Method and system for navigation in real time scale which use three carrier radio signals, transmitted by satellite, and ionosphere corrections

FIELD: real time scale navigation with the goal of detecting position of mobile device.

SUBSTANCE: in the invention, radio-signals of three different carrier frequencies are used, transmitted by satellites. Method includes a stage for determining indeterminacy of carrier frequency phase of "especially wide phase track", stage for estimating indeterminacy of phase of "wide phase track" and stage for resolving phase indeterminacy of one of frequencies. Additional stage includes utilizing ionosphere corrections in real time scale during third stage, where these ionosphere corrections are based on continuously updated ionosphere model of aforementioned ionosphere layer, computed by stationary ground-based support station, combined with geodesic data, computed by the so-called leading stationary ground-based support station.

EFFECT: ensured capability for precise navigation at distances exceeding 100 kilometers from supporting satellite communication stations.

2 cl, 17 dwg, 6 tbl

 

The present invention relates to a method and system for satellite navigation in real-time when using transmitted by satellite three signals of the carrier frequency and ionospheric corrections and more accurate corrections received through the continuously updated ionospheric models in real time, and the model is based on data obtained from satellite navigation systems, for example, implemented as a spatial voxel model.

How, in particular, though not exclusively, applicable in the field of high-precision instant navigation, typically with an accuracy within one decimeter, as will be shown below, at distances of the order of hundreds of kilometers or more.

In further illustration below we will focus on the preferred use of the present invention without limiting its scope.

In one of the commonly used modern methods of obtaining accurate positioning of the object, stationary or moving, and in the latter case, data about its position, its movement, direction of movement and/or speed, you must use the radio signals transmitted by artificial satellites orbiting the earth. The term "object" should be understood in a very General sense, namely as the ground is, sea or air vehicle. For simplicity, below we will refer to this object as "mobile device".

There are various known methods for producing the above-mentioned positioning. In particular, they are based on knowledge of the instantaneous position of multiple satellites in space (or a combination of satellites, since these satellites may or may not be geostationary) and the velocity of propagation of radio waves. The satellites are installed high-precision clock generators, and the transmitted signals include data time stamps, which make possible precise knowledge of the time of transmission and reception of data. Thus, it is possible to determine theoretical distance that separates artificial satellite in view of the mobile apparatus from the latest in the moment, knowing the speed of propagation of waves and the time required to achieve mobile device. If amenable to observation of a sufficient number of satellites, it is therefore possible to determine coordinates of the mobile device relative to the reference system in two dimensions (longitude and latitude on the earth), or even in three dimensions (longitude, latitude and altitude/vertical).

However, as will be shown, AFL is stvie accumulation of errors in the measurements due to various reasons, the calculated distances are only approximate and determining the position of the mobile device in a more or less significant extent, suffers from inaccuracy, depending on the used methods.

One of the most well-known satellite navigation system is a system known as the system "GPS" (global positioning system or global navigation and positioning).

As a rule, artificial satellites "GPS" (or similar system) to ensure transmission in two frequency ranges, usually denoted by the L1(carrier frequency equal of 1.575 GHz) and L2(carrier frequency equal there were 1,227 GHz), therefore, dependent "dual frequency", which is applied to them.

The use of these two frequencies in accordance with defined methods, well-known qualified specialists in this field of technology makes it possible to improve the accuracy of the location of the mobile device relative to the reference system, but requires that receivers "GPS" were more complex and more expensive.

Positioning can be done using two main methods: real-time or after the Commission, by performing what is known as "post-processing". The first case is usually called the resolution "one of periodicitatea" (a term which will be used below) or an instant resolution, and calculations are performed during the "sampling period" of one observation. The second method ("post-processing") makes it possible to improve the accuracy. However, while the latter does not have any major drawbacks for slow-moving mobile devices (e.g., ships), it is not suitable for mobile objects that move very quickly (for example, for aircraft).

The accuracy can be further improved by combining the signals transmitted by artificial satellites with signals emanating from stationary ground reference stations for satellite communications, the provisions of which are well known. However, if the mobile unit is subjected to large distances, it is necessary that the network of stations was relatively dense, especially in cases where high accuracy is required for positioning of the mobile device, which correspondingly increases the cost of the global system.

In addition, among the many reasons error differential ionospheric refraction when considering distances equal to tens of kilometers or more, is one of the main problems that affect the ability of instantaneous resolution of uncertainty phase of the carrier frequency and the investigator is about, the ability to provide navigation, in which accuracy is of the order of one centimeter with dual-frequency global navigation satellite systems, for example with the above system "GPS". This feature will remain true in the future trichostatin systems, like the system "GALILEO" and "MODERNIZED GLOBAL POSITIONING SYSTEM".

Essentially, currently planned systems that use the three carrier frequencies, offer the potential advantages of high success rate and high reliability in an instant resolution of uncertainty with the minimum number of geodetic calculations. That is, in particular, due to the fact that becomes available higher amount of data (i.e., in connection with the above three frequencies), which consequently increases the chances of getting instant resolution of uncertainty (one sampling period).

But in this case, this resolution may have a serious impact ionospheric refraction, as explained below.

To achieve high accuracy in an instant the position of the mobile device, in particular a mobile unit that travels long distances, there is still a need to implement methods that make it possible, in particular, reduce the harmful effects of ionospheric refraction.

In the prior art have been proposed various ways that meet such needs.

For example, there is a method known as "TCAR" ("the resolution of uncertainty three carrier frequencies"). This method is described in the article Ovulate and others, entitled "analysis of the WAY the UNCERTAINTY of the THREE CARRIER FREQUENCIES (TCAR) FOR PRECISE RELATIVE positioning IN the GLOBAL NAVIGATION SATELLITE SYSTEM GNSS-2", published in "Proceedings of the ION GPS 1998, IX-O-13, pages 1-6.

There is also a method known as "CIR" ("cascade integer resolution"). This method is described in the article Jaeva jhang and others, entitled "OPTIMIZATION of CASCADE INTEGER RESOLUTION WITH THREE CIVIL FREQUENCIES GPS SYSTEMS", published in "Proceedings of the ION GPS 2000".

These two methods use one common approach: uncertainty of the double-difference integers sequentially solved by computing cycles frequency waves. This calculation is carried out on the longest and shortest clock wavelength, including combinations of the phases of the carrier frequencies, the so-called "wide" phase track and "extra large" phase paths (wavelengths 7,480 m and 0,862 m, respectively) and the first carrier L1the frequency (wavelength 0,190 m).

The way TCAR, in particular, is the issue of the attitude, trying to solve the whole set of uncertainties instantly (in the mode of "one sampling period"). But on performance "TCAR" is strongly influenced by the decorrelation of the ionospheric refraction, which depends on the distance. In fact, as described below, the ionospheric delay is a problem if (as in the case of two-frequency systems) is its dual differential is more than 0,26 TECU (which corresponds to 4-cm delay for L1).

"TECU" is a unit used to describe certain electrical characteristics of the ionosphere. Essentially, the ionosphere can be described using a map, which represents the total number of electrons or "TEC" ("General content of electrons"). Map is the integration of the number of electrons in the vertical direction as a function of latitude and longitude. Unit TES called "TECU" (for "unit TES"), where 1 TECU=1016electrons contained in the cylinder, the cross section of which is 1 m2combined on-line monitoring of the artificial satellite. Charged particles in the ionosphere generated by the sun, the intensity of the radiation which varies naturally depending on the time of radiation. As the earth rotates on its axis below the ionospheric layer, it is usually considered that the map "TEC" is on the Alo reference which is fixed relative to the sun, but which varies in function of time.

As can be seen from a consideration of the ionosphere ("TEC") cards vertical delays calculated from data "GPS", the above threshold can be easily exceeded. Such cards are issued, for example, "jet propulsion Laboratory", University of Berne, and so forth, and published in the Internet, "University Corporation for atmospheric research" and other similar organizations.

Therefore, for an even better way to "TCAR" was developed integral method, known as "ITCAR" ("Integral TCAR"). This method is described, for example, in the above-mentioned article of Vallata and other

In this method, use the search algorithms and the navigation filter, in which the uncertainties are part of the output signals, and approximately estimated residual errors caused by ionospheric reflection. For a more detailed description of the method used it would be useful to turn to this article.

However, although it provides a significant improvement in the way "ITCAR" is still under the influence of the lack of knowledge of the double-difference ionospheric refraction, limiting thus the magnitude of the success of the resolution of uncertainty for distances greater than several tens of kilometers, as described in the article of Vallata, etc, entitled "RESOLUTION of UNCERTAINTY WHEN USING THREE CARRIER FREQUENCIES - PERFORMANCE ANALYSIS by using the DATA IN REAL TIME", published in "GNSS Symposium, Seville, May 2001.

It was also proposed, and in this case, due to improved accuracy in determining the position of the mobile device relative to the beginning of the countdown for combining the ionospheric model in real time, obtained from the data of the two frequencies generated by a network of fixed stations, with data from geodetic programs, and to use such data to perform ionospheric corrections. This method has been used with some success in resolving uncertainties in real-time in two-frequency systems of the type "GPS".

One method of this type, called "WARTK" ("global kinematics in real time"), described, for example, article Hernandez-Pajares and others, called "TOMOGRAPHIC MODELING of the IONOSPHERIC CORRECTIONS GLOBAL NAVIGATION SATELLITE SYSTEMS: EVALUATION AND USE IN REAL TIME", published in "ION GPS, 19-22 September 2000, pages 616-625. This method makes it possible to attenuate the harmful effects of noise caused by radio waves propagating in the ionosphere, and hence significantly improve the amount of success of phase uncertainty about which determine the position of the mobile device relative to the origin, but it requires a large number of computations to obtain the above-mentioned model in real time and to determine, in real-time ionospheric corrections for use in measuring distances.

The present invention is to eliminate the disadvantages of the methods and systems of the relevant prior art, some of which were mentioned above.

The present invention is the provision of a method for precise positioning in real-time (determining the position of the mobile apparatus, generally better than one decimeter) when using three-carrying signals transmitted by artificial satellites and ionospheric corrections derived from data in ionospheric model, which describes the area, walkable radiation, in combination with survey data.

Ultimately, in accordance with a first important characteristic of the present invention uses a simple way of instant permission (one sampling period) uncertainties that are transmitted to the artificial satellite of the three load-bearing phases above "TKAR" type. Accurate ionospheric corrections in real time, based on descriptive ionospheric models are generated stationary reference stations satellite tie is. These ionospheric corrections are transmitted to users, which include in their "TKAR".

The present invention has three important advantages.

Ability characteristic of the present invention, making it possible to obtain better performance than the method "ITCAR", at large distances, the situation is very far from the nearest reference station satellite communications. The method corresponding to the present invention, generally, provides instant resolution of over 90% uncertainties in more than 100 kilometres from the station, and almost 100% at a distance of about 60 km, even if not very favorable working scenarios: low ionospheric values and the conditions of maximum sunlight.

In comparable conditions, the methods corresponding to the prior art, in which there are three carrier frequencies, reaching typical values of success, which is only about 60%.

Just understand that this last characteristic is very advantageous because it does not require installation of a very dense network of fixed ground reference stations of satellite communication stations, spaced from each other for hundreds of kilometers). The result is a very significant total savings, for example, in the case of Europe: for coverage of this pin is the component can reduce the number of reference stations, satellite communications 99% compared with the network, in which the reference station satellite communications are separated from each other only at a distance of about ten kilometers, while maintaining the same accuracy in determining the position of the mobile device, which is obtained by using methods corresponding to the prior art. That is, in fact, the density required to obtain navigation accuracy better than one decimeter, in accordance with the method corresponding to the present invention, in its preferred application. In addition, a network of fixed ground based reference stations of a satellite communication required in a manner consistent with the present invention, very similar to the network, usually set for the European satellite navigation system, known by the acronym "EGNOS GNSS" (European geostationary navigation overlay system - a Global navigation satellite system"). This system is based on a combination of artificial satellites "IMMERSAT III", which suggests that there is substantial compatibility with the facilities that currently exist or that are in the installation process.

However, the method corresponding to the present invention is quite simple, like the way "TCAR". In particular, it requires the user of the receiver mobile devices is a) only a small number of computations compared to the ways "ITCAR" and "WARTK", which were developed for dual-frequency positioning systems as described above.

In addition, descriptive ionospheric model the field in real time, followed by radiation transmitted observable artificial satellites, uses only the data phase of the carrier frequency, and these data are combined with geodetic estimates calculated in the same centre, which can be one of the stations in the network of reference stations, satellite communications, called the leading radio station of satellite communication.

Therefore, the main objective of the present invention to provide a method of navigation in real-time using three bearing of the radio signal of the first, second and third different frequencies, which increase in value from the specified first before the specified third frequency, to determine the location of the user, called mobile device, and these signals are transmitted by a given number of transmitters installed on Board the satellites orbiting around the earth and in the mind of the specified mobile device, these signals are then received by a receiver associated with the specified mobile device and a receiver associated at least one ground station satellite communication among the set of stationary ground when Anzi, called reference stations, and these signals pass through the so-called ionospheric layer of the atmosphere surrounding the specified land, and have perturbations that generate the phase uncertainty in these carrier frequencies, characterized in that it includes at least the following steps:

the first phase, consisting in the determination specified in the mobile apparatus of the so-called uncertainty "extra-wide phase paths of the phase difference between the said third and second specified carrier frequency from the combination of pseudorange using one code value;

the second step consists in the evaluation in the specified mobile device, the so-called uncertainty "wide phase paths of the phase difference between the first and second carrier frequency from the specified uncertainty "extra-wide phase paths defined within the specified first stage;

the third stage, namely, in the specified mobile device, the resolution of uncertainty one of the frequencies above the specified uncertainty "wide phase track, valued within the specified second stage; and

an additional stage for use in real-time ionospheric corrections within a specified third stage, and these ionos Ernie correction based on continuously updated in real-time ionospheric model of the specified layer.

Another objective of the present invention to provide a satellite navigation system that implements this method.

Hereinafter the present invention will be described in more detail with reference to the accompanying drawings, where

Figa is a schematic illustration of a partial cross section of the earth and the ionosphere layer, which surrounds it, cut into voxels, and radiology generated by transmitters "GPS" on three artificial satellites, and three satellite earth stations receiving these signals;

Figw - schematic illustration of the architecture of a complete navigation system for implementing the method corresponding to the present invention, visible from a GPS receiver of the mobile device;

Figure 2 - schematic representation of the base line and the positions of the ground control station, satellite communication and mobile device relative to one of the coordinate axes;

Figure 3 - the increase in figure 2, illustrating the trajectory of the mobile device relative to one of the coordinate axes;

4 is a graph illustrating examples of delays expected from ionospheric models in real-time, relevant to the present invention, in comparison with the actual delays of the signals in the ionosphere;

5 is a graph illustrating examples of double differences "Inclined General electronegative" ("STEC"), measured in real time using descriptive ionospheric model, in comparison with the actual values;

6 is a graph illustrating examples of errors in determining ionospheric models in real-time double-difference "STEC" in comparison with two ionospheric rapids;

Figga-7D - graphs illustrating examples of the estimated error (in meters) in various navigation components;

Figga-8D - graphs illustrating examples of real errors (in meters) in some navigation components;

Fig.9 is a graph illustrating an example of the success rate for identifying instantaneous ionospheric double difference, which is large enough to resolve all uncertainties ("TECU" better than 0,26) for corrections with time delay in the range of 1-30 seconds; and

Figure 10 is a graph illustrating an example of a success rate in the instant determining ionospheric double difference for corrections with a lag time of up to 900 seconds.

Below without any limitation of the scope of the present invention, we will focus on the context of its preferred use, unless otherwise specified, that is, the method of high-precision satellite navigation using three carrier waves of different frequencies transmitted by artificial satellites, and corrections in real scale is e time, derived from descriptive ionospheric models in real-time area, the sensed radio frequency radiation of artificial satellites.

Next will be described the main stages of the method corresponding to the present invention when using typical numerical values for their illustrations. The method involves three main stages, which are similar to the steps of the abovementioned method "TCAR" and explained below:

Stage 1

To resolve the so-called uncertainty "extra-wide phase paths" (with a typical wavelength of 7.5 meters in the dataset of this experimental example) enter the combination code, known as the "pseudorange".

Among the known causes of errors is the phenomenon of so-called "multipath". Although multipath propagation of the pseudorange can reduce the percentage of successful attempts, this error is, in General, is low-amplitude compared to the large wavelength "extra-wide phase paths and, as a rule, possible to overcome this problem.

Actually, at the first stage of the model method "TCAR" (see, for example, the above-mentioned article by Vallat and others, 1998) to evaluate the double difference of uncertainty (between pairs of satellite receiver), hereafter referred to as ▿ΔNewfrom the double phase difference chosen to replace the th frequency "extra wide" phase track, called below ▿ΔLew(Lewis the wavelength of the carrier frequency is particularly wide phase tracks)when using a combination of pseudorange (or codes) Pewwho share the same magnitude and sign depending on the ionosphere, and combinations of phases. This perhaps gives greater wavelength, resulting from a combination of especially wide phase track. Values of Lewand Pewcan be determined using the following equations:

equation, where Lxis the measured phase of the carrier frequency (in units of length) with frequency fxand with a wavelength of λx. The values of X given in the attached TABLE I at the end of the present description, and it is clear that the numbers 1-3 are associated with the three frequencies in the described example. In TABLE I put together a certain amount of related data: frequency, wavelength dependence of the ionosphere and the maximum error of multipath propagation and various measurements that are useful for a good understanding of the method corresponding to the present invention. This data is associated with three lanes L1-L2frequencies, respectively, and phases (Lewand Lw) the carrier frequency is particularly broad and wide phase paths, respectively. pxis the appropriate measure of pseudodomain the STI". Errors multipath and measurement for the phase of the carrier frequency and the "pseudorange" marked as mx, Mxthat λxand Exrespectively (TABLE I also shows the maximum multipath propagation and typical error of measurement). Undifferentiated uncertainty λxbxthe phase of the carrier frequency, which contains the instrumental delay, after double differentiation becomes animated integer value wavelength λx▿ΔNx. Ionospheric delay αxI proportional inclined total electron content or "STEC", and the integration of the electron density along the beam emitted from an artificial satellite, typically measured in units of TECU, as described above. In equations (1) and (2) the symbol ρ*is a member that does not depend on frequency (the distance error of the clock signals, tropospheric refraction, and so forth).

From equation (2), which details not presented secondary members, for example, the end of the phase of the carrier frequency can be estimated double difference uncertainty particularly wide of the phase paths, referred to belowin the sampling period of the same dimension by subtracting the corresponding code as shown in the equation, privedennaya:

If no significant multipath spread, affecting the receivers (usually less than 3.7 m), the limit of error of this estimate is less than 0.5 cycle (as shown by the values given in TABLE I), which enables instant identification of uncertainty to the exact integer values.

Stage 2

The combination of wide uncertainty phase track estimate of the uncertainty of the phase of the carrier frequency is particularly wide phase paths obtained during the first stage. Most of the time the difference between these two forms of uncertainty particularly wide phase paths and differential ionospheric refraction (approximately 0,006 cycles/TECU operating frequencies of the presented example). Redispersible members are excluded. The main problems in this case are measurement error and multipath signals of the phase of the carrier frequency. Although typical values of the differential ionospheric refraction in the middle latitudes and with baselines less than 100 km are only a few TECU, using ionospheric correction can significantly increase the proportion of successful attempts at greater distances and more difficult ionospheric conditions.

Now will be described the main parts of this stage.

Once p is ruinae uncertainty ▿ ΔNew"a large wavelength resolved when the corresponding pseudorange, secondary uncertainty, for example, the combination of Lw "wide phase paths described by the following equation

(equation, in which φ1and φ2are the phases and frequencies of L1and L2), can be estimated from ▿ΔNewand from the phase difference of the carrier frequencies (see the corresponding constant values in TABLE I) in accordance with the equation:

Essentially, in the presence of medium multipath spread, erroneous member corresponding to equation (5), which also includes measurement error, normally less than 0.3 meters, i.e. less than 0.4 cycle. Wrong member remaining from the uncertainty corresponds to the ionospheric refraction when the value 0,0580 cycles/TECU for frequencies in this example (see TABLE I). This member can reduce the success rate, but is not critical member at mid-latitudes and at distances less than a few hundred kilometers, for which the double-difference values "STEC", hereinafter referred to as ▿ΔI, in General, less than 10 TECU.

A detailed example will be given below with reference to the diagram illustrated in figure 5.

In this Conte the CTE using ionospheric models in real-time improves the conditions for the success of the resolution of uncertainty "extra-wide phase paths in lower latitudes and for conditions with longer lines.

Stage 3

Uncertainty phase L1comes from the difference between the L1and unambiguous "extra-wide phase track," received previously. At this stage, the main problem is the corresponding differential ionospheric refraction (estimated 1.9 cycles/TECU), which may lead to errors of several cycles in the middle latitudes.

The third step is to implement an approach similar to the approach used in the second stage, but when using the phase difference of the carrier frequencies between the short and medium wavelengths, instead of medium and large wavelengths, as is evident from the following equation (6):

equation, where α1and αw(in General, αxare ionospheric coefficients defined in TABLE I, in the described example.

During the third stage, the combination of errors in the phase measurement of the carrier frequency and the average multipath propagation introduces another error, usually less than 0.2 cycle (see TABLE I). However, in this case, a critical issue is the ionospheric refraction, which can also introduce errors greater than 0.5 cycle (-1,945 cycles/TECU) for short baselines.

The main limitation can be overcome by calculating the ionospheric corrections in real time better than 0,26 TECU (0.5 C is (x TECU/1,9475) to ensure the correct integer estimation uncertainty. These corrections enter at stage 4, which will be described below.

Stage 4

To overcome the problem that occurs at the third stage (i.e. to determine the uncertainties of the shortest wavelength)to estimate differential ionospheric refraction define the model in real-time. This model calculates data from dual-frequency carrier phase at fixed locations in the network of reference stations for satellite communications. It is assumed that in this way a description of the ionospheric region passed through the radiation transmitted by the artificial satellite. The data of this model are combined in a known manner commissioned obtained from simultaneous geodetic calculations, the latter may preferably be performed on one of the stationary satellite earth stations in the network, called the leading radio station. The main advantage of this method is that it makes possible the assessment of differential refraction with standard error less than 0.25 TECU, even at distances of hundreds of kilometers from the nearest reference station and unstable ionospheric conditions. This accuracy, typically involves errors of less than 0.5 cycle when the instantaneous definitions of uncertainty L1for among them over long distances.

Distribution of free electrons in the ionosphere can be approximately determined using a lattice of volume units of resolution or "voxels", in which the density distribution of electrons in the system centered inertial earth is assumed to be constant at the moment.

A typical device of this type is described in figa. On figa schematically illustrated Meridian section of voxels VOXijk(i, j, k are the coordinates representing longitude, latitude and height, respectively), in which the density distribution of electrons in the ionosphere destroyed in accordance with equation (7) to define the data ionospheric model in real time.

This figa earth GT shown in partial section surrounded by a layer of CIONthe ionosphere, which was arbitrarily divided into two intermediate layers Withi1and Ci2, respectively. The lower layer height Withi1in the described example is 60 km, and the upper height is 740 km of lower layer height Withi2is 740 km, and its top height is 1420 km Angled surfaces bills VOXijkare 5×2 degrees each.

As an illustration, we introduced artificial satellites SAT1-SATn(three of which are shown in the drawings)on which the transmitters, GPSE1-PS En, respectively. These companions SAT1-SATnare referring to all or some of the ground stations of satellite communication, for example, three fixed reference stations ST1-STmshown in figa that contain GPS receivers, GPSR1-GPSRnand integrated computing means (not shown).

On FIGU schematically illustrates the architecture of a complete navigation system corresponding to the present invention, as viewed from a mobile device SUR.

This system requires a computer, interfaces, and physical resources, such as those used in some of today's deployed systems, such as EGNOS or WAAS.

This system to implement the method corresponding to the present invention includes a GPS receiver, SURGPSthat receives signals transmitted by artificial satellites, for example, artificial satellites SAT1-SATnshown in figa. From these signals of three frequency bands implemented a three stage method TCAR, as shown above, when using integrated computational means (not shown).

He also receives the data signals from the ionospheric model in real time, the designated reference station REF (from the nearest stations of a satellite communication network of ground reference stations ST1-STMshown in Fi is A) of the signals received from the satellites SAT1-GPSE1-SANn-GPSEnwhen using a GPS receiver, REFGPS. Station REF transmits data from the mobile apparatus SUR when using the transmitter REFE1.

Data geodesic configurations that can be defined in one of the so-called master station REFMtransmitted via the transmitter REFMEand distributed to the mobile apparatus SUR to be combined with data from the ionospheric model. Typically, this station also has a GPS receiver, REFMGPSas other stationary ground reference station satellite communications. Data geodetic configuration is calculated simultaneously with geodetic data model.

By the way, which is a well-known ionospheric calculations can be obtained by solving in real time, using a Kalman filter, the average electron density Neeach irradiated cell i, j and k (the symbols i, j and k indicate the coordinates of the three dimensions, as defined above)that are processed similarly to process arbitrary distribution, and standard functional noise 109-1010electrons/m3/√the hour. For example, the process of using a Kalman filter described in the book Gedman "Methods of allocation factors for discrete sequential assessment is key", published in Mathematics in Science and Engineering, Vol. 128, Academic Press, New York, 1977.

In accordance with an important feature of the method corresponding to the present invention, used only the data phase of the carrier frequency. Therefore, prevents interference code pseudorange and multipath. The polarization of the B1the phase of the carrier frequency (constant in each continuous arc data phase of the carrier frequency for each pair of satellite-receiver) are estimated simultaneously as random variables (which are random processes, white noise, when there is slippage of the cycle). The polarization filter decorrelated in real time from the values of the electron density, because the satellite geometry changes and changes of two types of unknowns become smaller, as shown in equation (7)below, which represents the model for the ionospheric information between a pair of the satellite receiver of a global navigation satellite system, and L1and L2are the phases of the carrier frequency, expressed in units of length, Li=L1-L2and Neis the electron density). L1is given by the following equation:

in which the value of "REC" and "SAT" refers to the receiver and the GPS satellite, respectively, a pair of "when the MSC-satellite" dl is an elementary distance on the line of sight between this couple, and Δsi,j,kis an elementary coordinate surface STEC, a i,j,k denote the coordinates in three dimensions, as specified above.

This approach is particularly suitable for determining the local characteristics of the electron density distribution, and the use of two layers with ground data from the global navigation satellite system (abbreviated as "GNSS") instead of a single layer, as in conventional methods, significantly reduces the risk of poor modeling of electronic content.

In the case of networks "WADGNESS" ("Differential global navigation satellite system for servicing a large area) is possible from the content of these corrections in real-time oblique total electron content or "STEC", obtained using equation (7):

first, for the formation of double-difference ▿ΔSTEC station-satellite with an error less than 1 TECU for obtaining secondary uncertainty (i.e., "broad diffraction paths") in the reference station satellite communications; and

secondly, for the interpolation in the receiver mobile device clear (unambiguous) values of L1that is very accurate values ▿ΔSTEC at the level of a few hundredths of TECU obtained after resolving the uncertainty the values.

If the interpolated value is better 0,26 TECU, the receiver of the mobile device may allow both uncertainty in real-time.

This method is essentially similar to the so-called method "WARTK", published in the above article, Hernandez-Pajares and others (2000). The results obtained so far using the method of "WARTK" in a few experiments, summarized in another article hernández-Pajares and other "Tomographic modeling of the ionospheric corrections global navigation systems: evaluation and use in real time", published in "ION GPS 2001", September, 2001. It will be useful to refer to these two articles for a more detailed description of this method.

In the kinematic method is one of the most important limitations is the existence of local ionospheric irregularities, for example, propagating ionospheric perturbations or TID ("Mobile ionospheric disturbances", which can give incorrect results when using linear interpolation of the ionospheric correction between the reference stations in the network. Performance can be improved by introducing data obtained using two frequencies from a mobile device.

In addition, in the case of calculations on the base station, long distance and most of the gradients electronic content can also limit the performance of this method. For this reason, in accordance with the characteristics of the method corresponding to the present invention was developed further procedure to provide stationary case and/or base stations, separated by thousands of kilometers, using the so-called code smooth "wide phase paths, to improve ionospheric model and, consequently, to facilitate the determination of uncertainty in real-time. This procedure is described, for example, article hernández-Pajares and other "Improved ionospheric calculations in real time on the GPS stations at very large distances across the equator", published in the Journal of Geophisical Research, 2002.

However, the methods used in the prior art, to solve real-time uncertainty in the receiver of the mobile device when using dual frequency global positioning system require a large number of geodetic calculations to ensure relatively good positioning, at about twenty centimeters, to allow combinations of free-floating ionospheric polarization and, consequently, the ability (using the above method "WARTK") resolution of uncertainty in real time, after the convergence time in a few minutes.

The present invention makes it possible to overcome these disadvantages of the prior art, in particular the way "WARTK". It makes it possible for the improvement of the instant ways to resolve uncertainties phase three carrier frequencies at medium and long distances between the reference stations (ranging from tens to hundreds of kilometers) and with a minimal number of geodetic calculations. The main improvement lies in the third step of the above method "TCAR" when using ionospheric corrections in real time, apply through ionospheric model, computed continuously in the reference stations.

Further improvement of the above-mentioned stage is also implemented in the method corresponding to the present invention. This improvement consists in using three different codes pseudorange, referred to in this application R1, R2, R3instead of a single code, which makes it possible to reduce the effects of multipath propagation in the resolution of uncertainty "extra-wide phase tracks.

In addition, in the preferred embodiment, performs verification using the pseudorange, "broad phase paths and codes frequency band C to determine the jumps in the estimation uncertainty associated with an error of allowing the attachment of the uncertainty of the longest waves. Essentially within the above-mentioned first and second stages, it is clear from equations (5) and (6)that one cycle in the error uncertainty "extra-wide phase track" gives approximately eight cycles of errors "wide phase track", and one cycle error "wide phase paths are converted into approximately four cycles of the error L1, which is the carrier frequency with the shortest wavelength in the described example. Very often these jumps in assessing the uncertainties are large enough for detecting and filtering when using the code.

This method corresponding to the present invention makes it possible to directly overcome the main limitations that make it impossible to navigate with a typical error of less than a few centimeters at large distances (>100 km).

In TABLE II, presents at the end of the present description, summarized comparative characteristics of the main ways of dealing with uncertainty in real-time, relevant prior art ("TCAR", "ITCAR", "WARTK"), and the method corresponding to the present invention.

For better illustration of the main characteristics of the method corresponding to the present invention, we now describe an example of an experiment performed on the Nove multiple datasets, transmitted modified signal generators installed on artificial satellites in the existing system the above global navigation satellite system ("GNSS", with simulated aircraft, ground-based users of mobile devices (e.g., ground vehicles or stationary objects. Take into account the different dynamic and ionospheric conditions.

As an illustration, and to provide significant example was a detailed study of the resolution in real time uncertainty of the receiver ground vehicle, hereinafter referred to as a mobile apparatus SUR, a relatively stationary reference station satellite communications, hereinafter referred to as REF, separated from the mobile apparatus SUR approximately 129 kilometers, in different situations. In the described example, the two carrier frequencies (GPS 1575,42 and 1227,60 MHz, respectively) and 24-channel carrier system "GLONASS" frequency 1615,50 MHz are three frequencies, adapted the simulator system "GNSS" for the four visible satellites for 20 minutes at 1 Hz, using twelve available channels to be valid receiver of the type known as "AGGA" ("Improved type of GPS/GLONASS ASIC"). "AGGA" is a digital integrated circuit, which enables high is kokorono digital signal processing for space applications, for example, badiozamani signals "DNSS and definitions of low earth orbit. This scheme is based on a standard integrated circuit "ASIC" (or "Integrated circuit private use"), (in the described example, the ATMEL T7905E). "GLONASS" (global orbiting navigation satellite system") is the Russian satellite navigation system, which is comparable with the system "GPS".

In the described example considered two main dataset, hereafter referred to as set "P5-M0 associated with the minimum signal strength and without multipath propagation, which represents the ideal case and dial P3-M1, associated with average power and the presence of multipath propagation.

In addition to the receivers of the reference stations, the simulated data sets, for ionospheric calculations we have added three stations existing in the network "IGN" ("the International GPS service"), at distances of more than 200 kilometers, which makes it possible to simulate a more realistic situation, containing a larger network of stationary points of contact.

Now we will show the results of a detailed study of the most difficult case, that is the longest baseline pair mobile apparatus SUR - station REF", or approximately 129 kilometers. The reference station REF is one of the stations ST1-STMshown n figa.

Figure 2 illustrates this example, the baseline and the station position REF and mobile apparatus SUR respect to the axes of coordinates, ellipsoidal latitude and longitude expressed in degrees.

Figure 3 is a magnified image of figure 2, illustrating the trajectory of the mobile device SUR and in this case with respect to the axes of coordinates, ellipsoidal latitude and longitude expressed in degrees.

The first aspect of the results relates to performance in real-time ionospheric filter. 4 shows examples of the estimated ionospheric delay model in real time, indicated on the chart by the symbol Tm, in comparison with the real ionospheric delays specified by the symbol Vv. These values correspond to the measured values from the experiment, made to illustrate the capabilities of the method corresponding to the present invention.

For accurate navigation is more important parameters, values, and the difference (error) between the estimated double difference "STEC",for mobile device SUR and their real values ▿ΔI, as shown in figure 5 and 6, in which the ordinate is expressed in units of TECU, and the abscissa represents the delay in seconds.

More specifically, figure 5 illustrates the double difference "STEC", as indicated by the symbols "ddSTEC", about Inanna in real-time using ionospheric models, corresponding to one of the most important aspects of the present invention, in comparison with the true values for the receiver of the mobile device SUR relatively farthest receiver, or REF (approximately 129 kilometers).

Figure 6 illustrates the error in the determination of ionospheric models in real-time double-difference "STEC", and in this case, the specified symbols ddSTEC". The actual values of the ionospheric model is compared with two ionospheric rapids, "Threshold1" (+0,26 TECU) and threshold "Threshold2" (-0,26 TECU), making possible the determination of the third uncertainty ▿ΔN1.

More than 92% of the ionospheric definitions have errors below limit threshold ±0,26 TECU. Therefore, they are precise enough to allow resolution of the three uncertainties in the absence of multipath spread and not taking into account the measurement error. The majority of the remaining 8% of the estimates with errors more 0,26 TECU, come from an artificial satellite, which was observed at low altitude and in a southerly direction for which ionospheric gradients are greatest. These results were slightly improved by adding to the four reference stations fifth station, performing calculations of the ionospheric corrections to the South.

As soon as the ionospheric correction were calculated and p is the steps from the core network, the described method for estimating the instantaneous resolution (in the mode of "one sampling period") of three uncertainties in the beam can be performed the steps of the method corresponding to the present invention, in the mobile apparatus SUR.

Summary of the main results of the uncertainty for the above sets P5-M0" and "P3-M1 data, respectively, provided in the form of two tables, TABLE III and TABLE IV, at the end of this description. The success rate of the three stages of the way "TCAR" is shown in the following three cases:

(a) without ionospheric corrections;

(b) with corresponding corrections of the model ionospheric correction of Klobuchar transmitted modern system "GPS",

(c) correction of ionospheric models in real time in accordance with the method corresponding to the present invention.

More specifically, in the example described in connection with TABLE III, the success rate (in %) applies to all 3834 checks permissions in real-time for uncertainty "extra-wide phase track, wide phase paths and frequency bands L1(respectively, ▿ΔNewthat ▿ΔNwthat ▿ΔN1for the mobile receiver apparatus SUR relative to the most distant fixed station REF (approximately 129 kilometres from th is s) and with the above set P5-M0 ideal data (the maximum power of the reception and without multipath spread).

TABLE IV is similar to TABLE III, but for the above set of P3-M1 data (average power level of the reception and multipath spread). The numbers in parentheses indicate the percentage of successful attempts relative to the total number of observations.

From TABLE III and TABLE IV it is evident that the method corresponding to the present invention, which combines a three stage method "TCAR" phase, the precise ionospheric models in real time, makes possible a significant increase in the share of successful attempts instant definition of uncertainty is not only the ideal scenario (set P5-M0 data: 0 to 92%), but also in more difficult scenarios (set P3-M1 data) with multipath propagation (35% even when using correction model Klobuchar, whereas the success rate reaches 92% to ▿ΔN1with the correction of ionospheric models obtained in accordance with the method corresponding to the present invention).

From TABLE IV it is evident that one of the important problems that arise when using a set of P3-M1 data subjected to multipath propagation, is the lack of reliability of the uncertainty estimates in accordance with the method "TCAR", ▿ΔNewand ▿ΔNwapproximately 10% and 4% incorrect instant definitions relevant to the military.

To increase validity, that is, to reduce the possibility of factoring in the incorrect ambiguities in this case, in the presence of the phase of the carrier frequency and to encode each of the multipath spread, you can use the appropriate pseudoallele, "broad-phase track and codes L1to attempt to identify errors, identify potential uncertainty preceding the longest wavelength in the way "TCAR" (uncertainty "extra-wide phase track" and "broad phase track", respectively), errors are amplified in 9 and 4 times the wavelength in the wide phase track" and "broad phase track", respectively, as shown in equations (5) and (6).

A summary of the relevant results are presented in two tables, TABLE V and TABLE VI, located at the end of the present description, respectively, when using the pseudorange and the smoothed pseudorange to filter out such important errors.

TABLE V is similar to TABLE II, but in this case the success rate of resolution of uncertainty after the validation, i.e. comparison with the uncertainty derived from the pseudorange to filter large surges in uncertainty "wide phase track" and L1and this is the races take place due to previous errors uncertainties larger wavelength. The last column shows the availability, i.e. the percentage 3834 observations that take place prior to the validation with the pseudorange. The number in parentheses "*" indicates the percentage uncertainties calculated after passing validation. As before, the numbers in brackets indicate the percentage of successful attempts relative to the total number of observations.

TABLE VI is similar to TABLE III, but to perform validation instead of "pure" pseudorange using the smoothed pseudorange.

It is obvious that the method corresponding to the present invention, provides a significant improvement of approximately 20%, the reliability (from 79% in TABLE IV to 91% in TABLE VI), with a relatively small decrease (16%) availability (which is reduced from 100% to 84%), due to the use of validation-aligned code. If, instead, use instant codes, reliability additionally improved (84%) and greater availability (90%). When using known models of GPS data, type of Klobuchar instead of the correction of ionospheric models in real time, corresponding to the method of the present invention, there has been a significant deterioration in results, accompanied by an almost complete absence of availability.

Available sets of data is x just described for experiment, despite their suitability for instant resolution of uncertainty, however, were very limited in determining the instantaneous position. Actually, for this experiment only four artificial satellites in sight within 20 minutes of data, so instant navigation solution for mobile device SUR had to calculate when using a set of "P5-M0" data without multipath spread and highly available signal-to-noise ratio to be used for navigation the minimum number of four satellites. In addition, he was expelled tropospheric delay, the calculation of which would require at least the fifth artificial satellite. In addition, the first interval from approximately 7200 seconds up to 7500 seconds was skipped in determining the relative positioning of certain configurations cutoff phase of the carrier frequency, potentially due to problems of measurement in the receiver during this period. On the other hand, from the point of view of the ionospheric corrections and the corresponding success rate of resolution of uncertainty the results almost similar to the results obtained for a set of "P5-M0" data (see TABLE III).

These limitations are due to the use of data sets, before the by existing systems, which have been subjected only to the minimum number of adaptation. Under the more realistic data set, for example, passed six or more artificial satellites, will disappear these important limitations on the definition of positioning. Actually, you can get a better geometry (geometric factor affecting accuracy), and the ability to detect and filter out artificial satellites, with errors of uncertainty. This will allow the navigation filter or Autonomous control algorithms of the receiver.

The results that correspond to the four artificial satellites contained in the set P5-M0 data shown in figa-7D, which illustrate the residual error to adjust (figa), and Eastern (pigv), North (figs) and vertical (fig.7D) components of the error instant positioning after the implementation of the method corresponding to the present invention, the mobile apparatus SUR, about 129 km from the reference station REF. The ordinate of the graph is specified in meters, and the abscissa (delay) in seconds.

For comparison on figa-8D presents the relevant data, but for real uncertainties.

The main characteristic of the residual errors before adjusting ▿ΔLc(Fi is A) errors are approximately 10 cm, associated with the error of the first cycle in L1(approximately 8%: see TABLE III), which generate errors navigation that is similar to the races. They are also shown in Fig. 7B-7D. They intensify the appropriate geometric factor affecting accuracy. These incorrect estimate the uncertainty of L1usually influence one double difference out of three that are available on the sampling period (the minimum number to determine positioning)so that this error affects the positioning of the three times (approximately 24% of the sampling period, with 76% of errors in three dimensions less than 5 cm and 100% less than 21 cm). Although the error distribution is not Gaussian, the resulting effective three-dimensional root-mean-square values are 7 cm, 3.5 cm and 2 cm for the East, North and vertical components, respectively.

To summarize these results, the root mean square error of 1.1 and 2 cm obtained for the East, North and vertical components, respectively, when the uncertainty is resolved correctly (approximately 92% of the trials and 77% of the sampling periods), and the root mean square error of 3.5 and 3 cm are to the East, North and vertical components, respectively, with the inclusion of the sampling periods, with incorrect resolution of uncertainty.

Furthermore, measurements, reduced by the residual calculation, before adjustment, the double difference of carrier phase and frequency errors instant navigation presented on figa-8D. We can note a significant increase in phase noise of the carrier frequency, especially in the vertical component, creating an error of approximately 5 refer to This trajectory (with three-dimensional root-mean-square value of 3 cm, 1.1 cm and 2 cm to the North, East and vertical components, and levels of 95% at approximately 2.2 and 4 cm, respectively) very clearly represents a solution that can be obtained by using the filter in real time instead of instant decision after the correct resolution of uncertainties within primary sampling periods.

For characterization of the effect of time lag in the ionospheric correction (due to, for example, potential problems in communication) delay of 1-30 seconds (30 sampling periods) were considered for computation of the ionospheric corrections in stations of satellite communication. For each of these delays, the percentage of successful attempts to "ddSTEC" (in TECU) was calculated to obtain the absolute accuracy of 0.26 TECU for mobile device at a distance of 129 miles. This percentage is shown in Fig.9 a function of lag time (in seconds). Quite obviously, the influence of the belts lag is negligible up to 30 seconds when the proportion of successful attempts more than 90%, achievable for all time lags.

Figure 10 examines the longer the time lag, in this case, the core network and corrections of the mobile device at the same time, so that the ionospheric sharp points remain close to each other. It is clear that after 5 minutes, the success rate decreases from 90% to 85%. After 10 minutes, the success rate drops sharply additionally, reaching 75%. These values may fall more sharply in those cases in which the above change of the differential ionospheric delay.

It is obvious that the average longitude of the lag time does not create an important problem for the method corresponding to the present invention, which can support the typical time lag of up to approximately 5 minutes.

From the above description it follows that the present invention solves the task.

The method corresponding to the present invention makes it possible, thanks to the application of ionospheric corrections in real-time when using the tomographic model, followed by the minimum number of geodetic calculations, obtaining instant full resolution of uncertainty. It also provides the ability to navigate with accuracy on the order of one centimeter at distances of more than 100 kilometers from the reference stations of a satellite communication.

<> The preferred application of the present invention will be in the future satellite navigation system, for example, the "GALLILEO or Modernized GPS"that implement the transmission carrier frequencies in three different frequency bands.

In accordance with the main feature of the method corresponding to the present invention, this ability is instant navigation with an accuracy better than one decimeter, is ensured due to the fact that the method of resolution of uncertainty phase three carrier frequencies type "TCAR", which is not very complex, combined with the determination of ionospheric models in real time to create the possibility of applying ionospheric corrections.

Examples of the experiments described in the above description, show a significant improvement of the results obtained by using methods corresponding to the prior art, under equivalent conditions:

instant success rate of approximately 60% or less increases to approximately 90% at distances of more than 100 kilometers from the nearest stationary ground reference station satellite communication and context in which it is difficult to obtain ionospheric model (at noon in the period of maximum solar activity);

high efficiency with time-delay will bring the flax 5 minutes in ionospheric corrections;

the corresponding navigation, despite the limited number of available satellites, for the experimental conditions, supported, for example, in data sets can be achieved instantly in the mode of "one sampling period and makes it possible to obtain three-dimensional RMS values of 3.5 and 2 inches to the East, North and vertical components, respectively;

in a preferred embodiment, the validation uncertainty in real-time makes it possible to improve performance as long as the method provides a simple reduction of multipath propagation of the pseudorange; and

this good performance was also confirmed in difficult conditions:

at low latitude (35 degrees instead of 48 degrees) with higher ionospheric values;

in extreme conditions in relation to tropical stations below the Northern Equatorial anomaly" of the ionosphere, where, as a rule, are of the highest gradients. In the latter case the user must supply his own ionospheric filter and combining it with the corrections of support networks and their own ionospheric measurements;

at high dynamics, enabling obespechenie accurate ionospheric corrections, amenable to use by aircraft in flight approximately 140 km from the nearest reference station satellite connection.

However, it should be obvious that the present invention is not limited to the examples of embodiments described to illustrate the present invention, particularly in connection with figure 1-8.

Finally, numerical examples have been presented only to illustrate and not for any limitation of the scope of the present invention. They come from the simple technology of choice within the capabilities of a qualified specialist in this field of technology.

2,1
TABLE I
X=1X=2X=3X=ewX=w
Frequency (fxMHz)1575,421227,61615,540,08347,82
Wavelength (λxm)0,19030,24420,18567,47990,8619
Measurement error phase(εxm)0,0020,0020,0020,10,01
Measurement error code (Exm)3332,1
The maximum multipath phase (mxm)<<0,05 (0,01)<<0,06 (0,01)<<0,05 (0,01)<<2 (0,5)<<0,2 (0,005)
The maximum multipath code (Mxm)<<450 (10)<<450 (10)<<450 (10)<<450 (10)<<450 (10)
Ionospheric factor (αxm/TECU)-0,1623-0,2673-0,1543-0,2083-0,2031

TABLE II
AdvantagesDisadvantages
"TCAR"The low computational load of the computerThe ionospheric error, severely limiting the resolution of the third uncertainty
"ITCAR"Results improved by integrating the TCAR in the navigation filterIonospheric delay continues to limit the resolution of the third uncertainty
"WARTK"Accurate modeling in real time; allows you to navigate to one hundred kilometers from the nearest reference station.High calculate the nutrient load of the computer: the necessity of calculation of the first decisions without consideration of the ionosphere for a mobile device and a considerable convergence time.
The method corresponding to the present inventionThe low computational load of the computer and accurate modeling of real-time ionospheric enable precision navigation "one sampling period" at distances up to 100 km from the reference station.

TABLE III
P5-M0/SUR2-REF5 (129 km)The proportion of successful attempts▿ΔNewThe proportion of successful attempts ▿ΔNwThe proportion of successful attempts ▿ΔN1
Without ionospheric correction100%100%0%
Correction100%100%33%
Klobuchar
Ionospheric correction in real time100%100%92%
TABLE IV
P5-M0/SUR2-REF5 (cm)The proportion of successful attempts ▿ΔNewThe proportion of successful attempts ▿ΔNwThe proportion of successful attempts ▿ΔN1
Without ionospheric correction90%95% (86%)3% (2)
Correction of Klobuchar90%95% (87%)35% (31)
Ionospheric correction in real time90%95% (86%)92% (79)

100%
TABLE V
P5-M0/SUR2-REF5 (cm)The proportion of successful attempts ▿ΔNew*The proportion of successful attempts ▿ΔNw*The proportion of successful attempts ▿ΔN1*Availability
Without ionospheric correction99%95%(94)0% (2)38%
Correction of Klobuchar99%97% (96)33% (32)38%
Ionospheric correction in real time99%96% (92)91%(84)90%
TABLE VI
P5-M0/SUR2-REF5 (cm)The proportion of successful attempts ▿ΔNew*The proportion of successful attempts ▿ΔNw*The proportion of successful attempts ▿ΔN1*Availability
Without ionospheric correction100%100% (100)0% (0)0,002%
Correction of Klobuchar100% (100)37% (37)0,002%
Ionospheric correction in real time100%100% (100)91% (91)84%

1. Navigation in real-time using three bearing of the radio signal of the first, second and third different frequencies, which increase in value from the specified first before the specified third frequency, to determine the position of the mobile apparatus, and these signals are transmitted by a given number of transmitters installed on Board the satellites orbiting around the earth and in sight of the specified mobile device, these signals are then received by a receiver associated with the specified mobile device, and a receiver associated at least one ground station for satellite communications among a set of fixed ground stations, called the reference stations, and these signals pass through the so-called ionospheric layer of the atmosphere surrounding the earth, and have perturbations that generate the phase uncertainty in these carrier frequencies, characterized in that it includes at least the following steps:

the first phase, consisting in the determination of the specified mobile apparatus is ATA (SUR), the so-called uncertainty "extra-wide phase track, which is a phase difference in cycles between a specified third and the second carrier frequency from the combination of pseudorange, using a single code value;

the second step consists in the evaluation in the specified mobile device (SUR), the so-called uncertainty "wide phase paths, representing the difference between the phases of the cycles between the said first and the second carrier frequency from the specified uncertainty "extra-wide phase paths determined during this first phase.

the third stage, namely, in the specified mobile device (SUR), the resolution of uncertainty one of the frequencies above the specified uncertainty "wide phase paths, estimated during this second phase; and

an additional stage for use in real-time ionospheric corrections within a specified third stage, and these ionospheric correction based on continuously updated in real-time ionospheric model of the specified layer (CION).

2. The method according to claim 1, characterized in that during this third stage the specified resolution of uncertainty perform specified on the first carrier frequency.

3. The method according to the .1 or 2, characterized in that the specified model is descriptive of the ionospheric model specified ionospheric layer defined by at least one of these ground control stations (REF), receiving signals transmitted by a given number of these satellites (SAT1-GPSE1- SATn-GPSEn), moving in an orbit around the earth (GT) in sight, and these signals contain at least two carriers of different frequencies, and that the specified model is determined from the phase data of these transmitted signals, and the fact that it provides phase data corresponding to the specified ionospheric model.

4. The method according to claim 3, characterized in that the determination specified ionospheric model is carried out to estimate the distribution of free electrons in the specified ionospheric layer (CION), as well as the fact that this estimation is performed approximately by dividing the ionospheric layer (CION) on a lattice of volume units (VOXijk) permission called "voxels"irradiated by the radiation of these signals propagating in the specified ionospheric layer (CION), in which the ionospheric electron density distribution at the moment is assumed constant, and the fact that the above definition of get through resolution real-the belts, the average electron density in each of the specified volume units (VOX ijk)irradiated specified radiation, when using the so-called Kalman filter.

5. The method according to claim 4, characterized in that it includes an additional step consisting in combining the data associated with the specified ionospheric model with survey data, computed simultaneously, and the fact that these geodetic data are computed only one of these fixed ground reference stations (REFM-REFME), called the master station, and apply to a given set of fixed ground reference stations (REF).

6. The method according to claim 1, characterized in that it includes an additional step consisting in the use of the three codes pseudorange associated with these three carrier frequencies, during this first phase to determine the so-called uncertainty "extra-wide phase paths of the phase difference between the third and second carrier frequencies.

7. The method according to claim 2, characterized in that it includes an additional step consisting in performing a validation check when using the pseudorange and codes "wide phase paths and code specified second frequency to detect surges associated with an error in the specified resolution of uncertainty specified first frequency.

8. SPU is if the navigation system for implementing the method according to any of the preceding paragraphs, characterized in that it contains many artificial satellites (SAT1-GPSE1-SATn-GPSEn), moving in an orbit around the earth (GT), and each of the satellites transmits these signals three different carrier frequencies, at least one mobile device (SUR), containing the receiver (SURGPS) these signals and integrated computational tools that meet the above first through third stages and integrate these ionospheric corrections derived from descriptive ionospheric model region of the ionosphere through which passed the radio emission of these signals indicated by the many artificial satellites (SAT1-GPSE1-SATn-GPSEn), as well as a number of stationary ground stations, called reference stations (REF), and each station comprises a receiver (REFGPSaccepting these signals specified artificial satellites, integrated computing means for determining the specified descriptive ionospheric model of the ionospheric layer (CION) and the transmitter (REFEfor data corresponding to the specified ionospheric model to the specified receiver (SURGPSthe mobile device (SUR), and, in addition, the fact that at least one of these fixed ground reference stations, n is called the master station (REF M)contains a receiver (REFMGPS) these signals specified by many artificial satellites (SAT1-GPSE1-SATn-GPSEn), the means to calculate the geodetic data and the transmitter (REFME) for distribution to the specified number of stationary ground reference stations (REF).

9. The system of claim 8, wherein the mobile device (SUR) is at a distance of more than 100 kilometers from the nearest stationary ground reference station (REF).



 

Same patents:

FIELD: radio-navigation, possible use in signal receivers of satellite radio-navigation systems used to determine client location and current time from signals of GLONASS, GPS, and similar radio-navigation systems.

SUBSTANCE: in the method satellite signals included in search list are found, until number of detected signals, which is sufficient for navigation measurements, is produced. In first positions of the search list three satellites are included in arbitrary order which ensure maximal coverage of Earth surface. Further satellites are included into search list in order which is determined by maximal sum of average distances between each one of them and all satellites positioned in the list closer to the beginning. The search for signals of each checked satellite is performed simultaneously using all free channels of receiver with distribution of search range between the channels. Satellite signal search is performed serially based on aforementioned list, starting from first one in the list, until first detection of signal. The search for signals of further satellites remaining in aforementioned list is performed in order determined by maximal difference between the sum of average distances between the satellite selected for check and all earlier checked satellites with undetected signals and the sum of average distances between that satellite and all earlier checked satellites with detected signals.

EFFECT: creation of method for blind finding of signals in multi-channel receiver of satellite radio-navigation signals, ensuring reduction of average search time required to solve navigational problem of the number of satellite radio-navigation system signals.

2 cl, 3 dwg

FIELD: submarine, marine terrestrial and close-to-ground navigation, in particular type GPS and GLONASS systems.

SUBSTANCE: at a time instant, that is unknown for the receiver, a signal is synchronously radiated by several radiators with known co-ordinates. The radiated signals are received by the receiver, the signal speed square is measured in the current navigation session, the Cartesian co-ordinates of the receiver are computed according to the moments of reception of the radiated signal and the measured signal speed square.

EFFECT: enhanced precision of location of the signal receiver.

2 dwg

FIELD: radio navigation aids, applicable in digital correlators of receivers of satellite radio navigation system (SPNS) signals, in particular, in digital correlators of receivers of the SPNS GLONASS (Russia) and GPS (USA) signals.

SUBSTANCE: the legitimate signal in the digital correlator is detected by the hardware, which makes it possible to relieve the load of the processor and use its released resources for solution of additional problems. The digital correlator has a commutator of the SPNS signals, processor, digital mixers, digital controllable carrier-frequency oscillator, units of digital demodulators, accumulating units, programmed delay line, control register, digital controllable code generator, reference code generator and a signal detector. The signal detector is made in the form of a square-law detector realizing the algorithm of computation of five points of the Fourier sixteen point discrete transformation with additional zeroes in the interval of one period of the, c/a code with a subsequent computation of the modules of the transformation results and their incoherent summation and comparison with a variable threshold, whose value is set up depending on the noise power and the number of the incoherent readout. The signal detector has a controller, multiplexer, complex mixer, coherent summation unit, module computation unit, incoherent summation unit, noise power estimation unit, signal presence estimation unit and a unit for determination of the frequency-time coordinates of the global maximum.

EFFECT: provided acceleration of the search and detection of signals.

2 cl, 6 dwg

FIELD: aviation engineering.

SUBSTANCE: device has on-ground automated system for controlling air traffic made in a special way, interrogation unit and re-translator mounted on air vehicles and made in a special manner as well. Autonomous duplication is used for measuring distance between flying vehicles.

EFFECT: widened functional abilities.

6 dwg

FIELD: radio communication.

SUBSTANCE: in accordance with the invention, the device for radio communication provides for getting of first time base (for example, getting of the code time shift) from the signal received from the transmitter on the ground. The predetermined shift based at least on the delay of propagation of received signal is applied to the first time base for obtaining of the second time base. For example, the second time base may be equalized with the time base of the satellite system of position finding (for example, GPS NAVSTAR).

EFFECT: synchronizing signal is generated, with has a time code shift based on the second time base.

6 cl, 12 dwg

FIELD: satellite radio navigation, geodesy, communication, applicable for independent instantaneous determination by users of the values of location co-ordinates, velocity vector components of the antenna phase centers of the user equipment, angular orientation in space and bearing.

SUBSTANCE: the method differs from the known one by the fact that the navigational information on the position of the antenna phase centers of ground radio beacons, information for introduction of frequency and time corrections are recorded in storages of the user navigational equipment at its manufacture, that the navigational equipment installed on satellites receives navigational radio signals from two and more ground radio beacons, and the user navigational equipment receives retransmitted signals from two satellites.

EFFECT: high precision of navigational determinations is determined by the use of phase measurements of the range increments according to the carrier frequencies of radio signals retransmitted by satellites.

3 dwg, 1 tbl

FIELD: the invention refers to navigational technique and may be used at designing complex navigational systems.

SUBSTANCE: an integrated satellite inertial-navigational system has a radioset connected through an amplifier with an antenna whose outputs are connected to a computer of the position of navigational satellites and whose inputs are connected with the block of initial installation of the almanac of data about satellites' orbits. The outputs of this computer are connected with the inputs of the block of separation of radio transmitting satellites. The outputs of this block are connected with the first group of inputs of the block of separation of a working constellation of satellites whose outputs are connected with inputs of the block of computation of a user's position. The system has also a meter of projections of absolute angle speed and a meter of projections of the vector of seeming acceleration which are correspondingly connected through a corrector of an angle speed and a corrector of seeming acceleration with the first group of inputs of the computer of navigational parameters whose outputs are connected with the first group of the outputs of the system. The system also includes a computer of initial data which is connected with three groups of inputs correspondingly to the outputs of the meter of projections of absolute angle speed and the meter of projections of a vector of seeming acceleration and to the outputs of a block of integration of information and also to the outputs of the block of computation of a user's position. At that part of the outputs of the computer of initial data are connected to the inputs of the computer of navigational parameters and all outputs are connected to the first group of the inputs of the block of integration of information whose second group of inputs is connected with the outputs of the corrector of an angle speed and the corrector of seeming acceleration, and the third group of inputs is connected to the outputs of the block of computation of a user's position. One group of the outputs of the block of integration of information is connected to the second group of the inputs of the block of selection of a working constellation of satellites, the other group of the outputs are directly connected to the second group of the outputs of the system, the third group of the outputs are connected to the inputs of the corrector of seeming acceleration and the fourth group of the outputs are connected with the inputs of the corrector of an angle speed and the second group of the inputs of the computer of initial data.

EFFECT: increases autonomous of the system, expands composition of forming signals, increases accuracy.

4 dwg

FIELD: railway transport.

SUBSTANCE: proposed repair team warning device contains "n" navigational satellites, dispatcher station consisting of receiving antenna, satellite signals receiver, computing unit to determine corrections to radio navigational parameter for signals from each navigational satellite, modulator, transmitter, transmitting antenna and computer of standard values of radio navigational parameters, movable object installed on locomotive and consisting of satellite signals receiving antenna, satellite signals receiver, computing unit for determining location of movable object, first receiving antenna, first receiver, first demodulator, matching unit, modulator, transmitter, transmitting antenna, second receiving antenna, second receiver and second demodulator, and warming device consisting of receiving antenna, receiver, demodulator, computing unit for determining distance between movable object, warning device, modulator, transmitter, transmitting antenna, satellite signals receiving antenna, satellite signals receiver and control unit.

EFFECT: improved safety of track maintenance and repair teams in wide zone of operation.

6 dwg

FIELD: radio engineering, applicable in receivers of signals of satellite radio navigational systems.

SUBSTANCE: the micromodule has a group of elements of the channel of the first frequency conversion signals, group of elements of the first channel of the second frequency conversion of signals, group of elements of signal condition of clock and heterodyne frequencies and a group of elements of the second channel of the second frequency conversion signals.

EFFECT: produced returned micromodule, providing simultaneous conversion of signals of standard accuracy of two systems within frequency ranges.

4 dwg

FIELD: aeronautical engineering; determination of aircraft-to-aircraft distance.

SUBSTANCE: aircraft-to-aircraft distance is determined by the following formula: where position of first of first aircraft is defined by azimuth α1, slant range d1, altitude h1 and position of second aircraft is determined by azimuth α2, slant range d2 and altitude h2. Proposed device includes aircraft azimuth indicators (1,4), flying altitude indicators (2,5), indicator of slant range to aircraft (3,6), adders (7, 14, 15, 19), multiplication units (8-12, 16, 18), cosine calculation unit 913), square root calculation units (17-20) and indicator (21).

EFFECT: avoidance of collision of aircraft; enhanced safety of flight due to determination of true aircraft-to-aircraft distance with altitude taken into account.

2 dwg

FIELD: the invention refers to radio technique means of determination of a direction, location, measuring of distance and speed with using of spaced antennas and measuring of a phase shift or time lag of taking from them signals.

SUBSTANCE: the proposed mode of determination of coordinates of an unknown transmitter is based on the transmitter's emitting of a tracing signal to the satellite, on receiving of signals of an unknown transmitter and legimite transmitters which coordinates are known, on forming a file of clusters, on selection of the best clusters out of which virtual bases are formed for calculating coordinates of legimite and unknown transmitters according to the coordinates of legimite transmitters and the results of calculation of their coordinates one can calculate mistakes of measuring which are taken into account at calculating the coordinates of the unknown transmitter.

EFFECT: increases accuracy of determination of coordinates of an unknown transmitter in the system of a satellite communication with a relay station on a geostationary satellite.

2 dwg, 1 tbl

FIELD: aeronautical engineering; determination of aircraft-to-aircraft distance.

SUBSTANCE: aircraft-to-aircraft distance is determined by the following formula: where position of first of first aircraft is defined by azimuth α1, slant range d1, altitude h1 and position of second aircraft is determined by azimuth α2, slant range d2 and altitude h2. Proposed device includes aircraft azimuth indicators (1,4), flying altitude indicators (2,5), indicator of slant range to aircraft (3,6), adders (7, 14, 15, 19), multiplication units (8-12, 16, 18), cosine calculation unit 913), square root calculation units (17-20) and indicator (21).

EFFECT: avoidance of collision of aircraft; enhanced safety of flight due to determination of true aircraft-to-aircraft distance with altitude taken into account.

2 dwg

FIELD: radio engineering, applicable in receivers of signals of satellite radio navigational systems.

SUBSTANCE: the micromodule has a group of elements of the channel of the first frequency conversion signals, group of elements of the first channel of the second frequency conversion of signals, group of elements of signal condition of clock and heterodyne frequencies and a group of elements of the second channel of the second frequency conversion signals.

EFFECT: produced returned micromodule, providing simultaneous conversion of signals of standard accuracy of two systems within frequency ranges.

4 dwg

FIELD: railway transport.

SUBSTANCE: proposed repair team warning device contains "n" navigational satellites, dispatcher station consisting of receiving antenna, satellite signals receiver, computing unit to determine corrections to radio navigational parameter for signals from each navigational satellite, modulator, transmitter, transmitting antenna and computer of standard values of radio navigational parameters, movable object installed on locomotive and consisting of satellite signals receiving antenna, satellite signals receiver, computing unit for determining location of movable object, first receiving antenna, first receiver, first demodulator, matching unit, modulator, transmitter, transmitting antenna, second receiving antenna, second receiver and second demodulator, and warming device consisting of receiving antenna, receiver, demodulator, computing unit for determining distance between movable object, warning device, modulator, transmitter, transmitting antenna, satellite signals receiving antenna, satellite signals receiver and control unit.

EFFECT: improved safety of track maintenance and repair teams in wide zone of operation.

6 dwg

FIELD: the invention refers to navigational technique and may be used at designing complex navigational systems.

SUBSTANCE: an integrated satellite inertial-navigational system has a radioset connected through an amplifier with an antenna whose outputs are connected to a computer of the position of navigational satellites and whose inputs are connected with the block of initial installation of the almanac of data about satellites' orbits. The outputs of this computer are connected with the inputs of the block of separation of radio transmitting satellites. The outputs of this block are connected with the first group of inputs of the block of separation of a working constellation of satellites whose outputs are connected with inputs of the block of computation of a user's position. The system has also a meter of projections of absolute angle speed and a meter of projections of the vector of seeming acceleration which are correspondingly connected through a corrector of an angle speed and a corrector of seeming acceleration with the first group of inputs of the computer of navigational parameters whose outputs are connected with the first group of the outputs of the system. The system also includes a computer of initial data which is connected with three groups of inputs correspondingly to the outputs of the meter of projections of absolute angle speed and the meter of projections of a vector of seeming acceleration and to the outputs of a block of integration of information and also to the outputs of the block of computation of a user's position. At that part of the outputs of the computer of initial data are connected to the inputs of the computer of navigational parameters and all outputs are connected to the first group of the inputs of the block of integration of information whose second group of inputs is connected with the outputs of the corrector of an angle speed and the corrector of seeming acceleration, and the third group of inputs is connected to the outputs of the block of computation of a user's position. One group of the outputs of the block of integration of information is connected to the second group of the inputs of the block of selection of a working constellation of satellites, the other group of the outputs are directly connected to the second group of the outputs of the system, the third group of the outputs are connected to the inputs of the corrector of seeming acceleration and the fourth group of the outputs are connected with the inputs of the corrector of an angle speed and the second group of the inputs of the computer of initial data.

EFFECT: increases autonomous of the system, expands composition of forming signals, increases accuracy.

4 dwg

FIELD: satellite radio navigation, geodesy, communication, applicable for independent instantaneous determination by users of the values of location co-ordinates, velocity vector components of the antenna phase centers of the user equipment, angular orientation in space and bearing.

SUBSTANCE: the method differs from the known one by the fact that the navigational information on the position of the antenna phase centers of ground radio beacons, information for introduction of frequency and time corrections are recorded in storages of the user navigational equipment at its manufacture, that the navigational equipment installed on satellites receives navigational radio signals from two and more ground radio beacons, and the user navigational equipment receives retransmitted signals from two satellites.

EFFECT: high precision of navigational determinations is determined by the use of phase measurements of the range increments according to the carrier frequencies of radio signals retransmitted by satellites.

3 dwg, 1 tbl

FIELD: radio communication.

SUBSTANCE: in accordance with the invention, the device for radio communication provides for getting of first time base (for example, getting of the code time shift) from the signal received from the transmitter on the ground. The predetermined shift based at least on the delay of propagation of received signal is applied to the first time base for obtaining of the second time base. For example, the second time base may be equalized with the time base of the satellite system of position finding (for example, GPS NAVSTAR).

EFFECT: synchronizing signal is generated, with has a time code shift based on the second time base.

6 cl, 12 dwg

FIELD: aviation engineering.

SUBSTANCE: device has on-ground automated system for controlling air traffic made in a special way, interrogation unit and re-translator mounted on air vehicles and made in a special manner as well. Autonomous duplication is used for measuring distance between flying vehicles.

EFFECT: widened functional abilities.

6 dwg

FIELD: radio navigation aids, applicable in digital correlators of receivers of satellite radio navigation system (SPNS) signals, in particular, in digital correlators of receivers of the SPNS GLONASS (Russia) and GPS (USA) signals.

SUBSTANCE: the legitimate signal in the digital correlator is detected by the hardware, which makes it possible to relieve the load of the processor and use its released resources for solution of additional problems. The digital correlator has a commutator of the SPNS signals, processor, digital mixers, digital controllable carrier-frequency oscillator, units of digital demodulators, accumulating units, programmed delay line, control register, digital controllable code generator, reference code generator and a signal detector. The signal detector is made in the form of a square-law detector realizing the algorithm of computation of five points of the Fourier sixteen point discrete transformation with additional zeroes in the interval of one period of the, c/a code with a subsequent computation of the modules of the transformation results and their incoherent summation and comparison with a variable threshold, whose value is set up depending on the noise power and the number of the incoherent readout. The signal detector has a controller, multiplexer, complex mixer, coherent summation unit, module computation unit, incoherent summation unit, noise power estimation unit, signal presence estimation unit and a unit for determination of the frequency-time coordinates of the global maximum.

EFFECT: provided acceleration of the search and detection of signals.

2 cl, 6 dwg

FIELD: submarine, marine terrestrial and close-to-ground navigation, in particular type GPS and GLONASS systems.

SUBSTANCE: at a time instant, that is unknown for the receiver, a signal is synchronously radiated by several radiators with known co-ordinates. The radiated signals are received by the receiver, the signal speed square is measured in the current navigation session, the Cartesian co-ordinates of the receiver are computed according to the moments of reception of the radiated signal and the measured signal speed square.

EFFECT: enhanced precision of location of the signal receiver.

2 dwg

Up!