Spacecraft position estimating system and method

FIELD: radio engineering, communication.

SUBSTANCE: system includes receiving stations (4) for receiving signals transmitted from the spacecraft (6) and a processing station (2) for receiving data from the receiving stations (4), where each receiving station (4) records, during a recording window (8), signals transmitted from the spacecraft (6) and transmits, to the processing station (2), data representing the recorded signals. The recording windows (8) associated with each of the receiving stations (4) are offset and/or have different size with respect to each other. The processing station (2) correlates the recorded signals to estimate the distance difference between the spacecraft (6) and each of a plurality of receiving stations and to estimate the spacecraft (6) position.

EFFECT: avoiding the need to send a reference signal pattern, emission by the spacecraft of any trigger sequence and the need to adapt the spacecraft, and improved estimation of the position of the spacecraft.

22 cl, 10 dwg, 1 tbl

 

The technical field to which the invention relates

The present invention relates to a system for estimating the position of the spacecraft, in particular to estimate the position of a satellite revolving around the Earth. The invention also relates to a method for estimating the position of the spacecraft, to the receiving station and the processing station to participate in the assessment of the status of the spacecraft and to a computer program which should be executed at the receiving station or at the processing station to participate in the assessment of the status of the spacecraft. The invention also relates to the position tracking of the spacecraft.

The level of technology

The definition and knowledge of the satellite's orbit at any point at any time is highly important for the satellite operator. Orbit can be derived from estimates of provisions, certain dimensions. For example, a geostationary satellite is nominally (i.e. is located according to the plan or calculation) on the designated position in longitude on the geostationary arc revolving around the Earth.

Moreover, the system estimates the position of the satellite allows precise determination of the maneuver. The definition of maneuver includes planning and control affecting the orbit of the executable maneuvers, taking into account economical (i.e. calculating the (e) using a limited amount of fuel on Board the satellite. Maneuvers are especially necessary for maintaining the geostationary satellite in its assigned longitude. This allows reliable telecommunication reception and transmission through anisotropic antenna of the satellite. Such maneuvers are necessary, since the geostationary orbit is unstable, especially due to the gravitational forces of the moon and Sun. Maneuvers also performed to change the orbit of the satellite in a controlled manner, in order to modify, for example, its position in longitude, which is indicated by reference as the demolition of the satellite, as well as its inclination or eccentricity.

In the case of the joint distribution of multiple satellites in the same orbital longitude there is a slight difference in longitude, inclination and eccentricity between different satellites. Such a scenario is complex and requires continuous evaluation location almost in real-time orbit determination for each satellite.

In addition to the geostationary satellites, accurate assessment of the situation can be very important and appropriate for any other type of satellites or space vehicles, whatever their type or destination orbit.

The position of the satellite can be determined by measuring the two-way delay. Measurement of two-way delay involves the transmission of the signal is from the transmitting earth station to the satellite and back from the satellite to the receiving earth station and the measurement of the elapsed time between the transmission signal from the transmitting ground station and its reception on the receiving ground station. In any of the following ways the position of each ground station is assumed exactly known.

The known method, the so-called trilateration method includes three ground stations each able to transmit and receive the reference signal. Typically, each station independently measures the delay between the transmission of the reference signal to the satellite and receive signals back from the satellite after it was relayed by satellite. Set of three stations, perform this step in parallel, provides three absolute distance measurements from three stations to the satellite so that its position is calculated.

Alternatively, the method of trilateration can be converted in the way of the pseudorange. In this way two-way delay is not measured independently, but together between ground stations so that only one ground station transmits a single reference signal. This first ground station receives signals back from the satellite. Other stations also accept a single reference signal from the satellite, which was transferred to the first ground station to the satellite. The distance between the other ground stations and satellites, therefore, are calculated implicitly.

The way the pseudorange requires a total time binding between ground stations, while videoes the config trilateration method does not require mandatory.

The position of the satellite can be carried out, solving the problem of the intersection of three spheres or using an algorithm, such as described in D.E. Manolakis: Efficient solution and performance analysis of 3-D position estimation by trilateration, IEEE trans. on Aerospace &Electronic Systems, Vol. 32, No. 4, Oct. 1996, pp 1239-1248.

There is a continuing need for improved systems and methods for estimating position of a spacecraft such as a satellite.

Lexical note

Before the description of the invention will be explained the use of the phrase "and/or" in the materials of this application.

In each case, the phrase "and/or" is used to indicate that words, signs, or items, United should therefore be taken together or individually, thus providing three are shown or specified variant implementation. In other words, if a and B are two terms, signs or paragraphs, the expression "A and/or B" includes three alternatives: "A and B", "A" and "B".

When first used the phrase "A and/or B, and then use the second expression "A and/or B" (for example, in the claim or claims of the invention or one of its dependent claims of the invention), it covers five alternative solutions:

- the first "A and B", and then the second "A and B",

- the first "A and B", and then the second "A"

- the first "A and B", and then second is e "B '

the first "A", and then the second "A"

the first "B", and then the second "B".

Additional use of the phrase "and/or" shall be understood in accordance with these principles, which are not covered by the contradictory combination. For example, when A and/or B" follows "C and/or D, each expression covers three alternative solutions, thus covering nine alternative solutions. However, for example, when "C" is a substitute for "object A", and when "D" is a substitute for "object B", it will be clear that when A and/or B" follows "C and/or D, it covers only five alternative solutions.

The invention

The present invention is directed to meet the above needs improvement systems and methods for estimating position of a spacecraft, such as the location of the satellite.

According to the invention, the system for estimating the position of the spacecraft. It includes many receiving stations, configured to receive signals transmitted from the spacecraft, and the processing station is configured to receive data from multiple receiving stations. Each of the receiving stations is made with the ability to record during the time window, in the materials of this application indicated by reference as the recording window, the signal p is redania from the space vehicle, and pass into the processing station data representing the signals recorded during the open record. Open records associated with each of the receiving stations is configured to be pushed and/or have different sizes (i.e. different length or duration) in relation to each other. The processing station is configured to correlate the recorded signals to estimate for each of at least one pair among the many receiving stations to the difference in the distances between the spacecraft and each receiving station of the pair, and on the basis of this provision of the spacecraft.

Thus, in the first alternative solution, open records associated with each of the receiving stations is configured to be shifted in relation to each other. In the second alternative solution, open records associated with each of the receiving stations made with the possibility to have a different size relative to each other. In the third alternative solution, open records associated with each of the receiving stations is configured to be pushed and have a different size relative to each other.

Next it will be explained in detail. Many receiving stations performed with the opportunity to receive RF signals transmitted on the spacecraft. Each of the multiple receiving stations records during the open record RF signals transmitted from the spacecraft.

Let's look at two of these receiving stations. Each of the two receiving stations records during open account or interval sequence of RF signals coming from the spacecraft interface. The beginning and end of the window is known on the basis of binding time total for the two receiving stations. Further, both the sequence of RF signals recorded on the two host plants, are transferred into the processing station. Information about the beginning and end of the window corresponding to the sequence of RF signals transmitted from each of the two receiving stations, is either known a priori processing station or transmitted by the receiving stations to the processing station. The processing station does not require any information about when the sequence of RF signals has been transmitted from the spacecraft. Similarly, the processing station does not require any information about the nature of the sequence of RF signals. The processing station determines on the basis of the known common time base time difference between the moments of arrival of the signals (DOA) part of the radio-frequency sequence, which was adopted and recorded two receiving stations during the two corresponding Windows account.

The time difference between the moments of arrival of RF signals sequence on the first and second receiving stations corresponds to the difference in the distances between the spacecraft and the first receiving station and between the spacecraft and the second receiving station. This time difference or offset is determined by correlation to the processing station two sequences of radio frequency signals. The correlation peak corresponds to the time difference or offset.

Through correlation of the pair recorded RF sequence taken at the first and second receiving stations, taking into account the properties of the propagation medium can be determined as the difference in distance between the spacecraft and the first and second receiving stations. Within Windows account corresponding to the pair recorded the radio-frequency sequences should be overlapping the interval during which the same part of the original radio-frequency sequence transmitted from the spacecraft, was adopted on first and second receiving stations. The spacecraft is located on two of the hyperboloid, the corresponding set of points in space, the La which the difference in distance between the spacecraft and the first and second receiving stations is constant.

Repeating the same process at the same time or essentially at the same point in time for the second pair of receiving stations and, if necessary, to the third pair of receiving stations can be defined two other hyperboloid, which can be located spacecraft. The spacecraft can be estimated as being at the intersection of these hyperboloids.

As explained above, the recorded signals are correlated pair on the processing station. Identification of the intersection of hyperboloids provides an assessment of the status of the spacecraft. This process, also known as three-dimensional hyperbolic positioning, requires actual transmission of sequences of recorded signals into the processing station. In addition, the sequence of signals must be recorded within a sufficiently long window records to obtain meaningful correlation peak. Win when the correlation processing is extracted from the available bandwidth of the signal multiplied by the sampling time.

The method is preferred in that the spacecraft does not require submission template reference signal or physical level, or modulated payload. The method also requires no start sequence, sluchennoe spacecraft, in order to enable recording at the receiving stations. Moreover, the spacecraft does not have to be specially adapted. In this sense, the method is passive. No need carrying out the interaction of the spacecraft. From the space vehicle is only required to send multiple electromagnetic signals that can be detected by the receiving stations. Already mentioned, but the method can handle and use patterns of the reference signals and the start sequence, emitted by the spacecraft, to enable the record to the receiving stations.

When designing this method and system, there is a need for transmission of sequences of recorded signals corresponding Windows account that has sufficient length to account for the difference in distance between the spacecraft and each of the first and second receiving stations, while still including enough temporal overlap with respect to the originally transmitted sequence to ensure meaningful correlation. Currently recognized that the implementation of a method or system that satisfies this need, can significantly increase the load on the communication lines between each of the receiving stations and processing stations.

Additional is about consciously, it is especially the case when the position tracking of the spacecraft, which requires a sequence of frequent assessments of the situation, in order, for example, to properly and timely manage the maneuver. The location of the receiving stations at a great distance from each other (for example, carrying more than 500 kilometers) is preferred to increase the angular resolution process and forecast assessment of the position of the spacecraft. The distance between each of the receiving stations and processing stations can, therefore, be so large that lines the range between the host station and the processing station does not exist. This further increases the network load caused by the transmission of the recorded sequences.

When performing shift Windows account deliberate and controlled manner the amount of data that must be transferred into the processing station is reduced. In addition or in the alternative (thus providing three alternative solutions), when installing a deliberate and controlled manner the size of each window record individually, so that the Windows account running with the ability to have a different size relative to each other, the amount of data which should be transferred into the processing station, also can be reduced. Instead write the received sequence of signals during the same Windows account (the same in relation to the total binding time) on each of the receiving stations, open records are shifted and/or size of the various sets in relation to each other. From the detailed description of specific embodiments with reference to the drawings (for example, fig.3b) it will be obvious, as in some versions of the implementation, which can be calculated shifts between the Windows account and/or the individual size of each window.

System measurement range disclosed in US 2004/0140930 Al (materials of the present application specified by the link as "c.[1]"), also applies to the estimation of the position of the spacecraft. It is interesting to highlight the differences between c.[1] the system and method of the invention, but it is better to understand the invention. In the system c.[1] the distance between the spacecraft and each of the at least three receiving stations is determined at the receiving stations. The values of certain distances are sent to the Central processing station, and based on the estimated position of the spacecraft. The assessment is based on the trilateration calculation on the distance values.

In one embodiment, in c.[1], as illustrated in his 6, the transmitting article is ncia (figure 605 figure 6) and the receiving station (figure 613 figure 6) together are used to provide two-way delay (difference between the time of emission and reception), providing the measured distance.

The invention is markedly different from c.[1] in that in the invention the signal actually recorded on the two host plants, are sent into the processing station to be correlated there in pairs. In addition, the invention uses the implementation of managed time offset between the Windows account and/or installation of individual size boxes of records at each receiving station to reduce the load on the network caused by the transmission of the recorded signals. Implementation of shift and/or sets the size of the window record as not solved, it is even not necessary in c.[1]. The problem of reducing the load on the network caused by the measurement system range, does not rise in c.[1]and, in fact, received and recorded signals are not sent over the network to a Central processing station in order to calculate the difference in time copies of the signals recorded at the receiving stations. Leave only the distance values and timestamps (for example, one of the time of emission and reception time figure 6 c.[1]).

In the above described embodiment of the invention of the window is configured to be shifted in time and/or vary in size in relation to each other. How aware of the specialist in the art, this does not exclude the episodes is systematic time shift, which would be closest to the value "0" between two Windows entries (for example, the shift between the beginning of two Windows accounts). Also, this does not exclude arise from time to time almost equal size between the two Windows entries. The aspect of the invention, which consists in the fact that the Windows account is configured to be shifted in time and/or vary in size in relation to each other, displays the ability from the point of view of the configuration prospects positioning system to perform the shift and/or individually to change the size of the Windows account deliberate and controlled manner, in order to reduce the amount of data that must be transferred into the processing station. Deliberate and managed the implementation of shift and/or sets the size based on a priori knowledge of the difference in distance between the first receiving station and spacecraft and the second host station and spacecraft.

The shift associated with a pair of receiving stations, is offset relative to the common reference time. In one embodiment, the receiving station is provided with a clock, synchronized with each other.

In one embodiment, some of the receiving stations are not synchronized in time with respect to each other. Components and structure of some of animusic stations can also be different, thus, causing a temporal offset relative to each other due to individual inherent delays of the station. The amount of desynchronization between the receiving stations known to the processing station, so that the processing station capable of sending important commands shift (important from the point of view of time binding). In other words, even if there is no time synchronization, and/or there is a difference in components and structure between host plants, since the processing station knows the length of time of the timing or the difference of the components or structures between the receiving stations, the processing station may consider the desynchronization and difference components and structures, in order to properly generate commands shift window and/or size (or run) to the receiving stations and the proper way to handle the results (recorded data) for significant correlation.

The problem addressed by the invention, are essential for determining the position of the spacecraft and are not applied directly (or, at least, with great difficulty are used to determine the position of the aircraft, as for example in the context of air traffic control. In air traffic control receiving stations are located only on the distance is several kilometers (more than 50 km), often having radioligist between the receiving stations and the Central processing station. Moreover, the current position of the aircraft can be anywhere in the geographical area covered by the transmission range of the receiving stations. In addition, the trajectory of the aircraft can be extremely dynamic and unpredictable in height or direction. Implementation of shift and resize Windows account solves the problems that are inherent in the spacecraft, and especially geostationary satellites. This is due to the geometric arrangement of the receiving stations (located at a large distance from each other, preferably more than 500 kilometers) and with the fact that the satellites are in a geostationary or quasigeostrophic orbit at 36000 km above the Earth's surface (the position of the satellite can be quite accurately predicted). Because of the significant distances between the receiving stations and the satellite, the time of receiving the satellite signal differ much more in time than the resulting window size required to obtain a good correlation peak. Implementation of shift and/or resizing Windows account optimizes the costs of window size and addresses the question of transferring large amounts of data in the Central processing station./p>

In the private embodiment, the spacecraft is limited within a particular "cell space". This cell space can be quasigeostrophic arc and thereby limits the place where it can be located spacecraft, and directly transfers it to the difference in distance between the receiving stations and spacecraft in the window size and the time offset for the various receiving stations.

In one embodiment, one of the receiving stations located in conjunction with the processing station.

In one embodiment, data transmitted from the receiving station to the processing station, are digitized for transmission. This increases the reliability of the system.

In one embodiment, the correlation processing station includes the correlation of pairs of the recorded signals, the detection position of the correlation peak representing the offset in time between the two copies, the calculation of the three-dimensional hyperbola or two hyperboloid corresponding to each pair, and calculating the intersection of hyperboloids that is the location of the spacecraft. To cope with cases in which the intersection of more than two hyperboloidal does not lead to a single point, the calculation may include an optimization in the with in themselves, for example, the method of least squares to find the nearest (most appropriate) the point of intersection and, thus, position.

In one embodiment, the correlation processing station includes the correlation of pairs of the recorded signals, the detection position of the correlation peak representing the offset in time between the copies of the two signals, the calculation result of the difference in time of the signal from the satellite to the respective receiving stations with known positions. These data are provided in a separate system for calculating the location of the spacecraft.

In one embodiment, the clock of each of the multiple receiving stations are synchronized.

In one embodiment, the shift between the Windows account associated with the two receiving stations, and/or the corresponding size of the Windows recording made with the possibility to be calculated on the basis of the position information of the spacecraft and the position of the two receiving stations. Time shift and/or window sizes can be calculated by the manufacturing station.

In one embodiment, the appropriate window size and/or time shift between the Windows account associated with the two receiving stations made with the possibility to be known a priori ratio is estwanik receiving stations and have no need to be provided by the manufacturing station.

In one embodiment, the system serves not only to assess the condition of the spacecraft, but also to track its position in time. In this embodiment, the shift between the Windows account associated with the two receiving stations made with the possibility to be calculated on the basis of, or in addition to the basis (if the shift is already calculated on the basis of knowledge, in advance, the position of the spacecraft) information about the position of the spacecraft, as the estimated processing station (on one or more previous operating stages).

In one embodiment, the position tracking of the spacecraft in time administered by each receiving station independently, using a priori information provided by the predictions of the shear box and/or sizes, and does not need to be provided to the processing station.

Tracking or feedback circuit may be provided as follows. Based on knowledge of the position of the spacecraft, obtained in advance, or the difference in distance between the receiving stations and spacecraft (the position of the spacecraft is not necessary, the difference between the distance/time DL the pair of receiving stations is sufficient for a feedback circuit, in order processing also acted in isolation for a single pair of receiving stations) and on the basis of pre-defined knowledge of the position of the receiving stations, processing station transmits commands shift window and/or size in the receiving station.

The term "range" indicates the link in the materials of this application on the distance between the spacecraft (or, in one embodiment, the satellite and the receiving station.

Each receiving station writes, on the basis of shifting the window and/or sizing, adopted from the processing station, the sequence of signals received from the spacecraft, and the sequence is sent into the processing station. Processing station receives the newly recorded signal sequence. It counts, i.e. it updates the estimate of the position of the spacecraft, re-calculates the difference in distance between the receiving stations and spacecraft, and finally calculates the new developments of Windows and/or window sizes, which must be passed. The cycle track is then executed again. The system and method makes it possible to reduce considerably the amount of data that must be transmitted over the communication lines between the host and the processing stations.

The window size W is recorded can be adapted and managed the manufacturing station, largely on the basis of the degree of accuracy relative to a priori knowledge of the position of the spacecraft. In this embodiment, the processing station is not only sends commands shift in the receiving station, but also commands window size. Command shift determines the start of the window, and the team size is its size. In one embodiment, the dimensions of the window are not adapted, and is preferably determined in advance taking into account all or most of the known time-related system parameters, including, for example, the temporary difference caused by the circular movement of the satellite during the day or after a maneuver or change the delays introduced by the atmosphere.

The position tracking of the satellite and the effective use of knowledge about the latest position to determine shifts and, optionally, recording window size is closely related.

In one embodiment, tracking is performed in real time. "Real time" here means operating timing of completion of the system response, to give a quick and successful definition of maneuver. Tracking in real time and the position control can be extremely necessary to control the position and maneuvers, using the on-Board engine(s) of the satellite.

In one embodiment, the receiving stations is one speed write operations per second and one is th evaluation of the resulting position for tracking. In one embodiment, is used to track the speed between one write operation for 0.1 seconds and one write operation per 24 hours.

When using the tracking window, the location of the correlation peak is detected, and the Windows are shifted to maximize their respective overlapping content for the next iteration in order, therefore, to track the time difference between the signals. For such tracking satellites allowed the prediction of the position, as they are typically exposed to relatively slow and constant movement in time relative to the receiving stations.

In one embodiment, uses a tracking shift is able to be calculated between the first write operation and the second write operation on the basis of the estimated position of the spacecraft, extracted from the first write operation. The first and second write operations can be, for example, separated by 0.1 seconds to 12 hours. The first and second write operations can be two consecutive write operations.

In one embodiment, at least one of the receiving stations located outside the service area of the descending line of the main lobe of the spacecraft. This configuration, frequent in the spine, well adapted to estimate the position of the spacecraft, which uses anisotropic or directional antenna with a narrow radiation pattern for communication towards the restricted area on Earth, with this allowing the receiving stations to be at a great distance from each other to provide good angular resolution to determine the position of the spacecraft. The farther receiving stations are from each other, the better the resolution.

This can be further explained as follows. The system is based on the correlation of the recorded signals. Thus, because of the inherent gain in the correlation processing technology, signals with low or negative S/N ratio (signal/noise) can be used in the correlation process, as the winning correlation paramount is given by the bandwidth of the signal multiplied by the sampling time Windows account. Win the correlation, therefore, is used to compensate for low or negative attitude S/N of the original signals, and the correlation may nevertheless provide significant peak.

In one embodiment, each window has a sufficiently small duration so that the effect of PPRs the EPA, the effects of the atmosphere (which can cause distortion and imperfection receiving input stages of the receiving stations do not have a significant impact on the correlation performed by the manufacturing plant, or, in other words so that correlation processing is not significantly affected by the frequency offset caused by Doppler effect caused by the atmosphere distortions and imperfections in the input stages of the receiving stations.

In one embodiment, at least one of the Windows account has a size between 4 microseconds and 10 milliseconds. In one embodiment, each window has a size between 4 microseconds and 10 milliseconds. These options provide implementation for applications in space vehicles, a good compromise between having enough long recording window to obtain a meaningful correlation peak and having a relatively short window entries to reduce the load on the communication lines between the receiving and processing stations.

In one embodiment, the estimated position of the non-geostationary satellite.

In one embodiment, the data sent from the receiving station to the processing station, contain any kind of information about the coordination in time, the contest is the action scene window.

The invention also relates to a method for estimating the position of a spacecraft using a number of receiving stations, configured to receive signals transmitted from the spacecraft, and the processing station is configured to receive data from multiple receiving stations. The method includes the procedure of recording and transmission, and the correlation procedure. The procedure of recording and transmission includes a record of each of the receiving stations during the open recording signals transmitted from the spacecraft, and transfer each of the receiving stations in the processing station data representing the recorded signals during the open record. Open records associated with each of the receiving stations, shifted and/or have different sizes (i.e., the length or duration) in relation to each other. The procedure of correlation comprises a correlation processing station recorded signals to estimate for each of at least one pair among the receiving stations to the difference in the distances between the spacecraft and each receiving station of the pair, and on the basis of this provision of the spacecraft.

The invention relates to a receiving station to participate in the assessment of the status of the spacecraft. The receiving station includes a first receiver, the second receiver is, the recording device and the transmitter. The first receiver is configured to receive signals transmitted from the spacecraft. A second receiver configured to accept an indication of a start time from the processing station as instructions for the beginning of the window and/or the size of the window as the instructions on the size of the window. A recording device configured to record during the Windows account that runs according to the indication of the start time and/or the instruction window size, the signals transmitted from the spacecraft. A transmitter configured to transmit to the processing station data representing the signals recorded during the open record.

The invention also relates to a manufacturing station to participate in the assessment of the status of the spacecraft. The processing station includes transmitter, receiver and correlator. A transmitter configured to transmit in each of the receiving stations is configured to receive signals transmitted from the spacecraft, specify the start time, referencing the beginning of the window, and/or the size of the window as the instructions to the size of the window. A receiver configured to receive from each of the multiple receiving stations data representing for vannie signals, transmitted from the spacecraft during the open record. Open records associated with each of the receiving stations is configured to be pushed or to have a different size relative to each other. The correlator is configured to correlate the recorded signals to estimate for each of at least one pair among the many receiving stations to the difference of the distance between the spacecraft and each receiving station of the pair, and on the basis of this provision of the spacecraft.

The invention also relates to a computer program configured, when executed on the receiving station or at the processing station, for implementation according to specific procedures of the receiving station or the specific procedures of the processing station of the above-described method of the invention.

Brief description of drawings

Next will be described embodiments of the present invention in conjunction with the attached drawings, on which:

Figure 1 schematically illustrates a system according to one variant of the invention, where the bottom of the drawing illustrates the implementation of the shift box and installing custom window size;

2, 3a and 3b schematically illustrate methods according to the options of carrying out the invention;

Fig.4 schematics which illustrates receiving station according to one variant embodiment of the invention;

Figure 5 schematically illustrates a processing station according to one variant embodiment of the invention;

6 shows an example of the differences between the ranges associated with the three pairs of receiving stations A-B, B-C and C-D for a period of 48 hours to facilitate the understanding of the problems associated with the size of the window;

Figa shows an example of the difference of the distances between the receiving stations B and C for 48 hours;

Fig.7b shows examples of Windows account for the two receiving stations B and C; and

Fig shows examples of Windows account for the two receiving stations B and C at time t and t+1 in the context of tracking the position of the spacecraft.

Detailed description

The present invention will now be described in conjunction with specific variants of implementation. It can be seen that the specific embodiments of serve to give the specialist in the art a better understanding and are not intended in any way to limit the scope of the invention, which is defined by the attached claims. In particular, an implementation option, described independently throughout the continuation of the description, may be combined for the formation of additional options for the implementation, if they are not mutually exclusive.

Figure 1 schematically illustrates the space is ical apparatus 6, receiving stations 4a, 4b, 4c, 4d, located on the Earth's surface at different positions, and the processing station 2 according to one variant embodiment of the invention. Spacecraft 6 radiates the RF signal toward the receiving stations, as illustrated by the dashed lines originating from the spacecraft 6. RF signals transmitted from the spacecraft 6, accepted on the receiving stations 4a, 4b, 4c, 4d.

Receiving stations 4a, 4b, 4c, 4d each record during a particular window 84a, 84b, 84c, 84dentries accepted sequence of RF signals. The nature or content of the sequence of signals is not known in advance receiving stations 4a, 4b, 4c, 4d, and therefore, there is no correlation performed at the receiving stations between sequences of received signals and a predefined sequence or a known template. Space apparatus 6 is not required to send any selected signal to measure distance, digital bit sequence or sequences to start recording. Any signal payload or communication channel emitted by the spacecraft 6, can be used for the evaluation process, including related digital and the analog signals of the payload, telemetry beacons or noise lamps transponder.

Received sequence of signals transmitted from the receiving stations 4a, 4b, 4c, 4d in the processing station 2. The sequence of signals may be digitized for transmission.

As schematically illustrated at the bottom of figure 1, each of the receiving stations 4a, 4b, 4c, 4d are made with the ability to record the received signals in time Windows 84a, 84b, 84c, 84drecords respectively. In relation to the total time (as illustrated by the vertical dashed line at bottom left of figure 1) Windows 84a, 84b, 84c, 84drecords respectively shifted by the shift Δt4a, ∆ T4b, ∆ T4c, ∆ T4d(where Δ is the Greek letter Delta and denotes here the shift). Therefore, the shift between Windows 84a, 84b pair of receiving stations 4a, 4b equal

Δt4b-Δt4a

a negative value in the exemplary illustration of Fig 1. The shift between the beginning of the Windows 84b, 84crecording of the second pair of receiving stations 4b, 4c is equal to

Δt4c-Δt4b

a negative value in the exemplary illustration of Fig 1. In conclusion, the shift between Windows 84c, 84drecording of the third pair of receiving stations 4C, 4d equal

Δt4d-Δt4c

and is a positive value in the exemplary illustration of Fig..

The sizes of Windows 84a, 84b, 84c, 84dentries are respectively size4asize4bsize4csize4d. The size can be set individually for each window 8 records and can, therefore, differ from each other, as illustrated. The use of different window sizes associated with the receiving stations 4, reduces the maximum overlap of the contents of the Windows 8 account for the correlation process.

Figure 1 illustrates the use of a shift Windows, and install a custom size. Use only one of these two techniques is also possible.

The number of receiving stations is not limited to four. If a priori information is available regarding the position of the spacecraft, the positioning system spacecraft may include only one pair of receiving stations or only two pairs of receiving stations. Similarly more than three pairs of receiving stations, forming more than four receiving stations, can be used to increase the precision of estimates.

The sequence of signals recorded on the receiving stations 4a, 4b, 4c, 4d, is sent into the processing station 2, which is a pairwise correlation. Can also be determined from the following shift, which should be the used for the Windows account on each of the receiving stations 4.

The determination of the position of the spacecraft 6 is based on calculating the time difference between the moments of arrival of the signal (TDOA; at the respective receiving stations located at known positions on the Ground). This can be visualized and solved mathematically as determining the intersection of two of hyperboloidal. Each hyperboloid receive the identification of the correlation peak associated with a pair of receiving stations 4, as described above. Determining the intersection of two of hyperboloidal to estimate the position of the spacecraft can be performed by solving a system of nonlinear equations. In the case where could not be found solving the system of nonlinear equations, optimal or most approximate solution in terms of the least squares method or the like can be selected as the position of the spacecraft.

Information about the position of the satellite may be provided on the computer screen (not illustrated) to facilitate the user in determining whether to be executed maneuver or maneuver was executed as planned, or in the calculation of the orbit of the spacecraft. Information about the position of the satellite can be in any form, including visualization or a mathematical expression. Moreover, information about the position of the satellite and/or RA is the values in the distances between the spacecraft and multiple receiving stations may be provided in any manner to any other system, using the information as input data for processing the combined or separated with the system of the invention.

Figure 2 illustrates the method according to one variant embodiment of the invention. The method includes 110 recording and transmission, which includes a record 112 of each of the receiving stations 4 during Windows 8 recording signals transmitted from the spacecraft 6, and the transmission 114 of each of the receiving stations 4 in the processing station 2 data, providing the recorded signals, which were recorded during the Windows 8 account. As explained above, Windows 8 records associated with each of the receiving stations 4, moved and/or have different sizes with respect to each other.

The method also includes 120 correlation, which includes the correlation of the processing station 2 recorded signals to evaluate the difference of the distance between the spacecraft 6 and each one of the receiving stations 4 pairs of receiving stations 4 (and so on, and similarly for other pairs of receiving stations, if necessary) and, based on this, the position of the spacecraft. The correlation is performed in pairs to identify the correlation peak. The position in time of the correlation peak, given deliberately set the offset corresponds to the time difference between the moments of arrival of signals between the near spacecraft 6 and each one of the pair of receiving stations 4 and thus, also for the difference in the distances between the spacecraft 6 and each one of the pair of receiving stations 4.

The method does not require knowledge of the actual distance between the receiving station 4 and spacecraft 6 as input for the evaluation process provisions. The method does not require knowledge or any information relating to the transmission time of signals from spacecraft 6, nor any information concerning the nature of the signals transmitted from the spacecraft 6, as the input data for the process evaluation of the situation.

Figa illustrates the method according to one variant embodiment of the invention. It differs from method 2 is the fact that as a result of the procedure 120 correlation not only get information about the position of the spacecraft and/or differences in the distance between the spacecraft and multiple receiving stations, as well as the team's new position and/or size of the window is calculated and sent from the processing station 2 in the receiving station 4. Therefore, the shift between the Windows account associated with the two receiving stations 4 and/or the size of the Windows account is calculated on the basis of the position information of the spacecraft 6 (and the known position of the two receiving stations 4).

Time shift Windows 8 account and install their size gave the e will be explained with reference to fig.3b in the context of the method according to another variant implementation, includes position tracking. The offset and size parameters iteratively adapted. Fig.3b shows the feedback circuit and illustrates the latest stages of shift, set the size (i.e. the size of the individual Windows) and tracking.

Next, let's look at two receiving stations 4a, 4b and their corresponding Windows 84a, 84brecords. The sizes of Windows 84a, 84brecords may be both set to be large enough to cover the maximum difference of distances associated with each one of the receiving stations 4a, 4b (referred to the range specified by the reference in the materials of this application as"Max diff A-B ranges"plus cost. The difference betweenMax diff A-B rangesequal ground distance along the baseline between the receiving stations 4a and 4b. If you use more receiving stations 4a, 4b, 4c, 4d, the window size should be considered the greatest difference ranges, such asMax diff C-D distance. If a priori information about the values of the difference of the distances is not known 131 ("No"), can be used to install 132 as the window size 84a, 84b, 84c, 84dwrite the sameMax diff C-D distanceas initial values (but not throughout the capture process).

A priori knowledge of testing the response difference of the distances can be extracted from any one of or any combination of:

- forecasts of the satellite's orbit (Kepler elements),

- information of the longitude of the satellite, located on the geostationary arc,

information approximate position (in the cell space) satellite in geostationary orbit

information extracted from any (past) measurements (e.g., pointing),

information learned from past correlations (which are a priori knowledge in the context of the current iteration).

If a priori information about the values of the difference of the distances of famous 131 ("Yes"), it can be used to set 133 size of the Windows 8 account and time shifts between the Windows 8 account. If there is no a priori information, the shift is not installed.

Then may occur optimization 134 input data for the correlation process. It may include:

a) scaling the window size associated with the receiving station 4A to the minimum required to obtain sufficient correlation peak (the available bandwidth of the signal multiplied by the sampling time or "BW*t product");

b) selecting a window size associated with the receiving station 4b, to match the accuracy of a prediction difference of the distances obtained in step 133.

Then there is a record 112, the transmission 114 and correlation of 120 sequences of signals, the backgrounds during the Windows 8 4aand 84brecords. Correlation 120 includes a detection position of the correlation peak. The difference between the ranges is the sum of the position of the correlation peak and the shift of the window (if any), as determined at step 133.

Then can generate 135 tracking parameters correlation. Once the position of the peak is found, the window size 84brecording can be reduced removal costs, bearing no relation to the case content to correlate with window 84arecords. The window size 84bentries can be reduced to the window size 84a. However, it is preferable to retain some border for window size 84bwrite to correct for movement of the spacecraft or satellite, over time, to the subsequent iteration record. The difference between the distances computed in step 120, provides the value of the updated parameter "shift box". Size computed in step 135, provides the value of the updated parameter "window size". These new values can then be used in the next iteration(s) either on the same data set or the second set of data recorded later in time ("tracking"). Using the values of the generated parameters for the next iteration(s) is illustrated by the arrow originating at the bottom fig.3b, for the beginning 135, and leading to the block 133.

Tracking can use one of the previous dimension or more previous measurements corresponding to multiple iterations.

Figure 4 illustrates the receiving station 4 according to one variant embodiment of the invention. The receiving station 4 is involved in the assessment of spacecraft 6. To do so, it interacts with the processing station 2. The receiving station 4 includes an antenna 42 or block 42 of the antenna, a first receiver 44 or block 44 of the first receiver, the recording device 48 or block 48 recording device and the transmitter 49 or block 49 of the transmitter and a second receiver 46 or block 46 of the second receiver.

The antenna 42 is configured to receive signals from the spacecraft 6, the position of which should be assessed. The antenna 42 is connected to the first receiver 44 which has a capability of receiving signals transmitted from the spacecraft 6 via the antenna 42. A second receiver 46 is configured to receive from the processing station 2 specify the start time (corresponding to a temporary shift in the quality of instruction for beginning Windows 8 account and/or the size of the window (corresponding to the duration) as instructions to the size of your Windows 8 account. The recording device 48 is configured to write at the time of the 8 entries, which starts in accordance with the indication of the start time and/or indicating the window size received from the processing station 2, the signals transmitted from the spacecraft 6. The recording device 48 may be adapted to activate the analog-to-digital Converter in accordance with the indication start time received from the processing station 2 at the time specified by specifying the start time in order to record the signal in the time Windows 8 account. Start analog-to-digital Converter can be performed based on the synchronized time base synchronized among the receiving stations 4).

The transmitter 49 is arranged to transfer into the processing station 2 data representing the signals recorded during the Windows 8 account.

Figure 5 illustrates the processing station 2 according to one variant embodiment of the invention. The processing station 2 is involved in the assessment of spacecraft 6. To do so, it interacts with the receiving stations 4. The processing station 2 includes a transmitter 22 or block 22 of the transmitter, the receiver 24 or block 24 of the receiver and the correlator 26 or block 26 correlator. The transmitter 22 is configured to transmit in each of the receiving stations 4, made with the ability to receive signals, before the nnye from spacecraft 6, specify the start time back to the beginning of Windows 8 account, and/or the size of the window as the instructions to the size of your Windows 8 account. In other words, specifying the start time is the instruction to the receiving station 4 to start recording of the signals received from the spacecraft 6. Specifying window size is the instruction to the receiving station 4 for recording signals received from the spacecraft 6 in the time window size. The window size is 8 entries can be a default value set within the receiving stations 4 (for example, within the block of memory) or may be sent to the processing station 2 as the instructions in the receiving station 4. The size of the window can also be adapted to account for a priori knowledge of the position of the spacecraft 6.

The receiver 24 is configured to receive from each of the multiple receiving stations 4 data representing the recorded signals transmitted from the spacecraft 6 during the Windows 8 account. Window 8 entries associated with each of the receiving stations 4, made with the ability to be shifted and/or have a different size relative to each other. The correlator 26 is configured to correlate the recorded signals to estimate the position of the spacecraft 6. The position of the spacecraft is what orrelation 26 in accordance with the above method of three-dimensional hyperbolic positioning.

The transmitter 28 offset and/or size or block 28 of the transmitter shift and/or size provided for the calculation of shifts and/or window sizes associated with Windows 8 entries, each of the receiving stations 4 based on the position of the spacecraft and/or the difference of the distance between the spacecraft and multiple receiving stations, calculated using the information received from the correlator 26.

Additional benefits provided by variants of the invention include:

- no need of measuring the two-way delay and no need for any structures downlink dedicated signals measurement range;

- lack of knowledge required to state the descending line (the line from the receiving stations to the space unit 6) in relation to the agreed time, load, Queuing, access, etc.;

- the lack of a time stamp transmitted signals required by the transmission unit of the satellite;

- lack of decoding and demodulation required at the receiving stations, thus reducing the delay introduced by the receiving stations 4, before associating the recorded sequence with information about the coordination in time and sending the recorded signals in the manufacturing stanciu (transformation with decreasing frequency and analog-to-digital (A/D) conversion can be yet implemented).

Next, referring to Fig.6, will be explained the problems associated with window size 8 entries. 6 shows the values of the differences between the ranges and the drift in the real system (illustrated sample; this explains the intermittent nature of the data). The system includes four receiving stations 4 (denoted here as A, B, C and D)that write and perform a mark on a time shared signal transmitted in the broadcast mode geostationary satellite.

The correlation process uses a Windows account, during which the receiving station 4 select the incoming signals. You can use a single, shared Windows account for all of the receiving stations and, therefore, the job total initial recording time and the total size of the recording (duration). However, using only common Windows account for satellite system generates constraints implementation due to the time of signal propagation between the satellite and the ground station (the distance the signal in two directions approximately 77000 km, two-way delay of about 258 milliseconds). Implementation limitations include various frequency drifts during the recording time, caused by the Doppler effect (causing distortion, which must be alleviated before correlation), and h is some amount of selected data, which should be transferred to the Central processing station. Using a single, shared Windows account is, therefore, unsatisfactory.

To illustrate the problems and solutions proposed by the invention, it provides a numerical example based on real data collected:

satellite is located on 19.2E on the geostationary arc;

four receiving stations distributed in Europe by 3000 km baseline (Luxembourg, Stockholm, Rome and Madrid) under the pan European beam satellite;

- 48-hour observation period.

In the example, only the total window accounts for all of the receiving stations would be approximately 2400 kilometers plus 10=percentage the border of reliability, requiring the capture window length of 9 milliseconds. Using different Windows for each receiving station makes it possible to reduce it to the desired recording time for each station and, thus, the external impact.

With reference to figa and 7b will be further explained in the shifted window and the location and size of the Windows account. Figa shows a plot of the difference of the distances between the receiving stations B and C (in the example in the case of high diurnal changes) within 48 hours. The average rating "Cf(C)" the difference of the distances determines the shift between the Windows account receiving stations B and C. Because the ku diurnal pattern can be identified from the movement of the satellite (from B-C equation difference ranges), the size of the Windows account must be defined in order to cover the daily change in the equation of the circle to the middle position.

Fig.7b shows open records to the receiving stations B and C, the shift corresponding to Cf(B-C) and the window size. The window size is retrieved from:

Window size = max(diurnal variation, boundary evaluation guideline) + border entries.

Diurnal variation for this example is equal to 3.9 kilometers. Border assessments should cover the possibility that the satellite is outside the daily forecast changes (e.g., maneuver, other orbit than geostationary). In this example, two specific host plants (B and C) can be shown geometrically that the movement of the satellite in the 200-kilometer cubic cell space in the geostationary arc causes the maximum difference of distances of 20 miles between the receiving stations B and C. Must be installed an additional border reliable records to ensure sufficient overlap of signals between a common part transmitted by the satellite signal for both Windows. The minimum number of samples to eliminate false correlation peaks is estimated at 200 samples (4 milliseconds at a sampling rate of 50 MHz) signal bandwidth of 25 MHz. The window size is equal then

PandCmmi> ep_aboutKnand[Km]=20+(200insbaboutpaboutK(fs=50MGC)with a=1,2Km)=21,2Km

With reference to Fig will be explained tracking. Method according to one variant embodiment of the invention includes the process of tracking changes in the position of the satellite and the difference of the distances for pairs of receiving stations, such as receiving stations B and C. For each iteration of the correlation window B and write the correlation process displays a peak at a particular "time shift", which was the first way is used to calculate the location of the satellite. These secondary "time-shift" are the inputs to the tracking system, which determines the prediction of the next position and, therefore, the next shift between the Windows account associated with the receiving stations b and C.

Update shift window at each iteration maximizes the number of overlapping signal between the Windows account. Thus, it can be reduced the size of the Windows account. Chart Fig shown for illustrative purposes a simple prediction by extrapolation of the first order.

In conclusion, without direct reference to any of the drawings the advantages of tracking, including in particular the reduction in the size of the window for real-time systems, can be further explained as follows. The availability of accurate short-term forecast of the difference between the delay based on recent measurements has the advantage that the size of the Windows account is no longer required to cover the daily pattern and can therefore be reduced. This reduction optimizes the amount of data that must be transmitted over the network to the Central processing station to meet the needs of real-time systems.

Reduced the capture window should allow to track changes equation difference of distances per second according to second to second basis. Therefore, in addition to the minimum number (represented by the symbol "#" in the equation below) of samples required to avoid ambiguity signal and spurious correlations (i.e. 200 samples or 4 milliseconds at a sampling rate of 50 MHz for a signal bandwidth of 25 MHz), the size of the window should include a boundary error in the estimation of the new position.

The window size of records = # of samples in order to avoid ambiguity (00) + limit evaluation errors.

The equivalence between the error in the estimation of the new position and the number of additional samples required for its coverage is calculated, assuming the frequency (fs) write 50 MHz and in the worst case, errors in the estimation of 1 metre:

GpandnandCanderror estimates=2|AboutCenKandaboutWandbKand|with afs=2insbaboutpKand

=> window size = 202 sample = 1,21 km

As shown below in Table 1, a tracking system according to the invention can reduce the influence of external factors and speed data rate in 2000 compared to a system based on a unique window.

td align="justify"> Shifts between 3 equations
Table 1
Performance technologies
Aspect/technologyUnique
window
The shifted windowTracking
Coverage from the signal-to-sampleDiurnal variation 1 equationsThe minimum number of samples, in order to avoid uncertainty in the signal
The window size2640 km21,2 km1,21 km
Data rate/second440 Kbit/station3.5 Kbit/station*202 Bits/station*
The system data rate/second1,76 MB14 Kbit808 Bit
Win1~1/125~1/2000

Note: the "window Size", "data Rate" and "System data rate can be deduced from each other by assumption 8 bit A/D and sampling frequency of 50 MHz.
*The same window at each receiving station (e.g., B) can be used in all the equations (for example, A-B, B-C).

Where the materials of the present application and which uses the term "block" (for example, in the case of the antenna unit 42, block 44 of the first receiver unit 48 recording device, block 49 of the transfer unit 46 of the second receiver unit 22 of the transmission unit 24 of the reception unit 26 of the correlation unit 28 of the transmitter shift and/or size), there is no restrictions on how can be distributed elements of the block. I.e. the constituent elements of the unit can be distributed in different software or hardware components or devices for implementing the intended function. Moreover, some of the blocks can be assembled together to perform their functions through the combined single unit.

The aforementioned blocks may be implemented using hardware, software, a combination of hardware and software, pre-programmed ASICS (application-specific integrated circuit), etc. Unit may include a unit of computer processing (CPU), a storage unit, an input/output (I/O)blocks network connections, etc.

Although the present invention has been described on the basis of detailed examples, detailed examples only serve to provide professionals in the art a better understanding and are not intended to limit the scope of the invention. Volume invented the I is much better defined by the attached claims.

1. System for estimating the position of the spacecraft (6), including:
many receiving stations (4)made with the ability to receive signals transmitted from the spacecraft (6); and
the processing station (2)which has a capability to accept data from a variety of host plants (4);
in which
each of the receiving stations (4) done with writing during a time window (8), as set forth below window (8) records the signals transmitted from the spacecraft (6), and pass into the processing station (2) data representing the recorded signals in the time window (8) record;
Windows (8) entries associated with each of the receiving stations (4)made with the possibility to be joined and/or have a different size relative to each other; and
the processing station (2) made with the possibility to correlate the recorded signals to estimate for each of at least one pair among the many host plants (4) the difference in the distances between the spacecraft (6) and each receiving station (4) of the pair and on the basis of this provision of the spacecraft (6).

2. The system according to claim 1, in which the shift between the Windows (8) entries associated with two receiving stations (4), and/or the size of each window (8) the recording made with the possibility to be calculated on the again
information about the position of the spacecraft (6) and/or at least one of a difference of distances, and
the position of the two receiving stations (4).

3. The system according to claim 2, in which the offset and/or size to be computed by the processing station (2).

4. The system according to claim 1 for estimating and tracking the position (6) of the spacecraft in which the shift between the Windows (8) entries associated with two receiving stations (4), and/or the size of each window (8) the recording made with the possibility to be calculated on the basis of, or in addition to using information about the position of the spacecraft (6) and/or at least one of a difference of distances as estimated processing station (2).

5. The system according to claim 4, in which the offset and/or size to be calculated between the first write operation and the second write operation on the basis of the estimated position of the spacecraft (6) and/or at least one of a difference of distances extracted from the first write operation.

6. The system according to claim 1, in which at least one of the receiving stations (4) is located outside the service area of the descending line of the main lobe of the spacecraft (6).

7. System according to any one of the preceding paragraphs, in which each window (8) the record has a size between 4 microseconds and 2 Milli is cundari.

8. Means for estimating the position of the spacecraft (6)using multiple receiving stations (4)made with the ability to receive signals transmitted from the spacecraft (6), and the processing station (2)which has a capability to accept data from a variety of host plants (4), and the method includes
procedure (110) recording and transmission, which includes a record (112) of each of the receiving stations (4) during the time window (8), as set forth below window (8) recording signals transmitted from the spacecraft (6)and (114) of each of the receiving stations (4) in the processing station (2) data representing the recorded signals in the time window (8) record;
in which window (8) entries associated with each of the receiving stations (4), shifted and/or have different sizes with respect to each other; and
procedure (120) correlation, which includes the correlation of the processing station (2) of the recorded signals to estimate for each of at least one pair among the many host plants (4) the difference in the distances between the spacecraft (6) and each receiving station (4) of the pair and on the basis of this provision of the spacecraft (6).

9. The method according to claim 8, in which the shift between the Windows (8) entries associated with two receiving stations (4), and/or the size of each window () entry is calculated on the basis of
information about the position of the spacecraft (6) and/or at least one of a difference of distances, and
the position of the two receiving stations (4).

10. The method according to claim 9, in which the shift and/or calculate the size of the processing station (2).

11. The method of claim 8 for estimating and tracking the position of the spacecraft (6), in which the shift between the Windows (8) entries associated with two receiving stations (4), and/or the size of each window (8) recording calculated on the basis of, or in addition to using information about the position of the spacecraft (6) and/or at least one of a difference of distances as estimated processing station (2).

12. The method according to claim 11, in which the shift and/or size is calculated between the first write operation and the second write operation on the basis of the estimated position of the spacecraft (6) and/or at least one of a difference of distances extracted from the first write operation.

13. The method according to claim 8, in which at least one of the receiving stations (4) is located outside the service area of the descending line of the main lobe of the spacecraft (6).

14. The method according to any one of PP-13, in which each window (8) the record has a size between 4 microseconds and 2 milliseconds.

15. The receiving station (4) to participate in the evaluation of the position of the spacecraft (6), containing
first the th receiver (44), made with the possibility of receiving signals transmitted from the spacecraft (6);
a second receiver (46), configured to receive from the processing station (2) specify the start time as instruction for the start of the time window (8) and/or the size of the window as the instructions for the size of the time window (8);
recording device (48)made writable during a time window (8)is started according to the indication of the start time and/or the instruction window size, the signals transmitted from the spacecraft (6), time window (8), as set forth below window (8) accounts; and
transmitter (49), made with the possibility of transfer into the processing station (2) data representing the recorded signals in the time window (8) record.

16. The receiving station (4) of clause 15, which is located outside the service area of the descending line of the main lobe of the spacecraft (6).

17. The processing station (2) to participate in the evaluation of the position of the spacecraft (6), containing
the transmitter (22), made with the possibility of transmission of each of the receiving stations (4)made with the ability to receive signals transmitted from the spacecraft (6), specify the start time, referencing the beginning of the time window (8)specified above as a window (8) recording and/or decree of the Oia window size as the instruction window size (8) entries;
the receiver (24)is made with the possibility of receiving from each of the multiple receiving stations (4) data representing the recorded signals transmitted from the spacecraft (6), in the time window (8) record;
in which window (8) entries associated with each of the receiving stations (4)made with the possibility to be joined and/or have a different size relative to each other; and
the correlator (26)made with the possibility of correlation of the recorded signals for evaluation for each of the at least one pair among the many host plants (4) the difference in the distances between the spacecraft (6) and each receiving station (4) of the pair and on the basis of this provision of the spacecraft (6).

18. The processing station (2) 17, in which the shift between the Windows (8) entries associated with two receiving stations (4), and/or the size of each window (8) the recording is made with the ability to be computed by the processing station (2) on the basis of
information about the position of the spacecraft (6) and/or at least one of a difference of distances, and
the position of the two receiving stations (4).

19. The processing station (2) on 17 or p for assessing and tracking the position of the spacecraft (6), in which the shift between the Windows (8) entries associated with two receiving stations (4), and/or the size of each isocon (8) the recording is made with the ability to be computed by the processing station (2) on the basis of, or in addition to using information about the position of the spacecraft (6) and/or, at least one of a difference of distances as estimated processing station (2).

20. The processing station (2) according to claim 19, in which the offset and/or size to be calculated between the first write operation and the second write operation on the basis of the estimated position of the spacecraft (6) and/or at least one of a difference of distances extracted from the first write operation.

21. The processing station (2) 17, in which each window (8) the record has a size between 4 microseconds and 2 milliseconds.

22. Machine-readable media containing a computer program configured, when executed on the receiving station (4) or on the processing station (2)for, respectively, the specific procedures of the receiving station or the specific procedures of the processing stations of the method according to any one of PP-14.



 

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15 cl, 6 dwg

FIELD: radio engineering, communication.

SUBSTANCE: network comprises an aeronautical segment (200) having an aeronautical user segment composed of a plurality of aircraft (2) having on-board radio-frequency receivers (21) capable of measuring delays of the navigation signals transmitted by the satellites (GNSS) and an aeronautical data communication means (5) between the plurality of aircraft (2) and the ground segment (300) in order to transmit measurements to the ground segment (300), and means, at the level of the ground segment (300), of receiving measurements used for calculating said grid, the measurements of delays coming from the plurality of aircraft (2) and from the plurality of ground stations (SBAS G).

EFFECT: high reliability in the communication structure of ionosphere corrections using existing aircraft communication lines directed towards a ground segment, high accuracy of corrections, enabling detection of small ionosphere perturbations, eliminating constraints for coverage of sea areas or mountain areas.

8 cl, 3 dwg

FIELD: radio engineering, communication.

SUBSTANCE: system has a measurement module having a GLONASS/GPS navigation antenna, a GLONASS/GPS navigation receiver, a controller with nonvolatile memory, a transceiving communication module, an accumulator battery, an accumulator battery charging device, sensor equipment for the measurement module, external sensor equipment, a personal computer-based automated operator workstation with a processor.

EFFECT: high accuracy of calculating characteristics of displacements of engineering structures and continuous monitoring of parameters of displacements of engineering structures.

2 dwg

Glonass receiver // 2491577

FIELD: radio engineering, communication.

SUBSTANCE: GLONASS receiver includes: a signal receiving unit (11) for receiving a plurality of signals, having different frequencies, from a plurality of artificial satellites, respectively; a temperature detector (33); a memory device (14) for storing group delay characteristics of each signal in the signal receiving unit (11) in form of group delay characteristic data and for preliminary storage of the temperature dependence for group delay of each signal in the signal receiving unit (11) in form of temperature dependence data; and a position computer (15) for correcting reception time of each signal using group delay characteristic data, for correcting the reception time of each signal based on temperature and temperature dependence data and for calculating the current position in accordance with the corrected reception time.

EFFECT: high accuracy of positioning a GLONASS receiver by reducing the effect of temperature without complicating performance, reducing efficiency of the manufacturing process, complicating the circuit, increasing dimensions and reducing sensitivity.

14 cl, 8 dwg

FIELD: radio engineering, communication.

SUBSTANCE: wireless device receives a first signal and obtains an identifier indicating a first location from the first signal. The first signal can be received from a cellular base station and the first identifier can be a mobile country code. The wireless device uses the identifier to determine accessibility of signals from a regional satellite system in the first location. If signals from the regional satellite system are accessible in the first location, the wireless device retrieves information associated with one or more artificial satellites in the regional satellite system. The information may include pseudorandom numerical codes and the search range in Doppler mode which corresponds to the first location. The wireless device receives a second signal and processes the second signal to obtain first satellite signal information. The wireless device determines its location at least partly based on first satellite signal information.

EFFECT: improved satellite search efficiency, shorter search time without using additional information such as ephemeral information, almanac or satellite time information.

22 cl, 6 dwg

FIELD: radio engineering, communication.

SUBSTANCE: mobile objects and a control station are fitted with navigation satellite system signal receivers which provide communication with satellites. Connections between base stations and mobile objects are provided through broadband radio access equipment. Connections between the control station and base stations are provided through synchronous fixed communication equipment and an optical link. Using a geoinformation system, coordinates of mobile objects obtained from satellites, calculated differential coordinate adjustments, measurement data from telecommunication equipment of a broadband radio access network and time synchronisation of the navigation satellite system with equipment of the broadband radio access network, the information processing unit of the control station determines the exact location of the mobile object in real-time using software.

EFFECT: high accuracy of locating mobile objects in real-time and improved functional capabilities of the system.

1 dwg

FIELD: radio engineering, communication.

SUBSTANCE: method includes steps of detecting a first navigation signal at a reference location; estimating timing of a bit edge of a data signal modulating a second navigation signal received at said reference location based on the first navigation signal; and performing pre-detection integration to detect said second navigation signal over an interval of said second navigation signal based, at least in part, on said estimated timing of said bit edge, wherein said first navigation signal is transmitted according to a first format and said second navigation signal is transmitted according to a second format different from said first format.

EFFECT: reduced ambiguities in received SPS signals.

26 cl, 15 dwg

FIELD: physics.

SUBSTANCE: network element (M) for generating backup data has a control element (M.1) for generating back up data relating to one or more base stations (S1, S2) of at least one navigation system, and a transmitting element (M.3.1) for transmitting back up data over a communication network (P) to a device (R). The positioning device (R) has a positioning receiver (R3) for positioning based on one or more signals transmitted by base stations (S1, S2) over at least one of the said satellite navigation systems; a receiver (R.2.2) for receiving back up data relating to at least one navigation system from the network element (M); and an analysis element (R.1.1) adapted for analysing the received back up data in order to detect information relating to the status of the said one or more signals from the base stations (S1, S2) of the navigation system. The said information relating to the status of the said one or more signals from the base stations (S1, S2) contain indicators to the base station (S1, S2) to which the signal relates, and the said status, which indicates suitability of the signal for using. The device (R) is adapted such that, the signal indicated as unsuitable for use is not used for positioning.

EFFECT: increased accuracy of determining location by providing the positioning device with a list of defective signals transmitted by a specific satellite.

29 cl, 6 dwg, 5 tbl

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