# Three-dimensional positioning apparatus and method

FIELD: radio engineering, communication.

SUBSTANCE: three-dimensional positioning apparatus (10) with a secondary radar base station (12), designed to measure range to repeaters (14) and has at least one radar antenna (16), has a GNSS receiver (18), designed to measure GNSS signals and has a GNSS receiving antenna (20), an inertial measuring unit (22), designed to determine the position of the GNSS receiving antenna, as well as at least one radar antenna in a common coordinate system relative a zero point, and an integrating processor (24, 30, 31), to which are transmitted psedorange measurements of the GNSS receiver, radar range measurements, and movements of the apparatus relative the axis of the common coordinate system measured by the inertial measuring unit (22), and which determines the three-dimensional position of the common reference point by combining the measurements and data, and arm compensation is carried out based on the measured movements.

EFFECT: high accuracy of positioning.

13 cl, 4 dwg

The invention relates to a device and method for three-dimensional positioning of the aircraft in accordance with paragraphs 1 and 10 of the claims, respectively.

Three-dimensional positioning of the aircraft with high requirements for accuracy, availability, continuity and integrity is important, for example, during landing of helicopters. In this case, first of all, in low visibility landing or in the absence of such visibility can cause problems. For three-dimensional positioning during landing approach known various technologies, which will be briefly explained along with their disadvantages.

For example, the integration of GPS (global positioning system) and INS (inertial navigation system). However, thus cannot achieve the accuracy requirements of the three-dimensional positioning, which, for example, required when the Autonomous landing. Moreover, different correction data is only limited available. This solution is also sensitive to the effects of stations active electronic countermeasures.

Further known a so-called landing radars, which leads to high operating costs. In addition, from the point of view of determining the position and integrity of the user segment is not fully Autonomous, because the control is proizvoditsa in the ground segment instead of the user segment. And finally, require expensive ground segment large mechanical size and large power consumption.

Following the known technology is a local two-dimensional radar system positioning, which is still limited to two-dimensional positioning, and usually has less availability and continuity than in the case of the combined approach for data from sensors with GNSS (global navigation satellite system) and IMU (inertial measurement unit). Due to the limited system of two-dimensional positioning, it is not considered as assistance when boarding and suitable only for taxiing.

Finally, the famous navigation subsystem on the basis of pseudo-satellites (Integrity Beacon Landing), which, however, easily affected stations active jamming, because it operates exclusively in the GNSS frequency band. High precision positioning can be achieved by using algorithms phases of the carrier frequency, which adversely affects the availability and complicates the integration of the concept. In addition, this technology leads to increased cost of ground segment due to land-based pseudo-satellites (Integrity Beacons).

Here are the following publications, which are solutions positioning:

- Thibaut G.: "Cost Benefit Analysis on Prcision Approach and Landing Systems (PALS) - Final Report", NIAG SG-99 final report, volume 2, document AC/224(ACG5)D(2007)0002, July 2007,

- C.E. Cohen, Pervan B.S., Cobb H.S., D.G. Lawrence Powell J.D., Parkinson B.W.: "Precision Landing of Aircraft Using Integrity Beacons, Global Positioning System:: Theory and Applications Volume II, volume 164, American Institute of Aeronautics and Astronautics, Washington, DC, 1996,

- Greenspan R.L.: "GPS and Inertial Integration," in Global Positioning System: Theory and Applications Volume II, volume 164, American Institute of Aeronautics and Astronautics, Washington, DC, 1996, and

- "SYMEO Local Positioning Radar System LPR-B 1D", product documentation, Symeo GmbH, 2009

The task of the invention is to provide an improved three-dimensional positioning, which makes possible the unification of requirements for accuracy, availability, continuity and integrity to the solution positioning.

This problem is solved by a device for three-dimensional positioning of the aircraft with signs of paragraph 1 of the claims and by way of the three-dimensional positioning of the aircraft with signs of paragraph 10 of the claims. Additional execution of the invention are subject of the dependent claims.

The invention provides for the integration of measurements of the secondary radar, GNSS measurements and IMU data in integrating the processor, which determines the three-dimensional position based on the combined measurements and data. With the goal of integrating the integrating processor can conduct Association change the events and data using non-linear filter. According to the invention the calculation of the three-dimensional position on the user side can occur independently in the integrating processor. This ensures the integrity monitoring solution positioning directly to the user, where the alarm information integrity is required first. Used for the purposes of the invention, the secondary radar, which can be made as operating in C-band (IEEE) FMCW (frequency-modulated radar CW) radar has a base station that is attached to a custom block, and several distributed in local limited area of transponders (stations). Measuring distances between the base station and the transponder is based on measuring the time delay of the signal. While the base station emits FMCW radar signal, by which the transponders are synchronized within a strictly defined time period. After successful synchronization, the transponders emit FMCW signal response. So when combining measurements and data in a nonlinear filter to achieve good observability of the States of the filter, as well as high availability and integrity of solving the problem of three-dimensional positioning, in a nonlinear filter may optionally be processed GNSS-source measurements and IMU data. Thus, with whom persons trouble-free to the shadows of the signal and the limitations of the geometric dimensions of the local system secondary radar.

One object of the invention is a device for three-dimensional positioning of an aircraft having a ground segment, which includes several transponders, and the user segment located on an aircraft and includes:

base station of the secondary radar, which is designed for measuring the distance to a transponder and has at least one radar antenna

- GNSS-receiver, which is designed to measure the GNSS signals, and has a GNSS reception antenna,

- inertial measurement unit, which is designed to determine the position of the GNSS-receiving antenna, and at least one radar antenna in the related aircraft General coordinate system, and

integrates the processor, which summarizes measurements of pseudorange GNSS receiver, the radar measurement of range, and the measured inertial measurement unit move GNSS receiving antenna and at least one radar antenna relative to the axis common coordinate system and which defines a three-dimensional position of a common reference point by combining the summed measurements and data, while taking into account measured GNSS receiving antenna and at least one radar antenna is compensation shoulders defined by the distance from overall pornostache to GNSS receiving antenna, at least one radar antenna and an inertial measurement unit.

By combining measurements and data from various sources it is possible to achieve trouble-free and very reliable determination of the three-dimensional position stored in the user segment of a reference point that is important for the safe approach of the helicopter on the landing.

The secondary base station can be made to operate in C-band (IEEE) and use FMCW radar signals to measure the distance.

The device may be provided by an inertial navigation system, which has an inertial measurement unit, and integrating the processor is made to run outside the operating region of the system of secondary radar three-dimensional positioning of the aircraft with first United navigation-based pseudorange measurements of the GNSS receiver and inertial navigation measurements of the inertial navigation system, and to perform within the operating area of the three-dimensional positioning of the aircraft with the second joint navigation on the basis of the radar measurement of range, pseudorange measurements of the GNSS receiver and inertial navigation measurements of the inertial navigation system.

Thus, while, for example, phase of flight in which BA is new station secondary radar too far removed from the transponder ground segment, determining three-dimensional position is based GNSS and inertial navigation, and during the phase of approach to the landing place near transponders for three-dimensional positioning is additionally enabled the measurement of the distance between the antenna/antennas and radar transponders, which has a higher weighting factor than the pseudorange measurement GNSS receiver, due to the lower variability of the measurements. Thus, in various phases of flight can achieve the optimal three-dimensional positioning on the available measurements and the corresponding variability of the measurements.

To solve the existing problems filtering the integrating processor may have a Sigma-point Kalman filter for processing the pseudorange measurement GNSS receiver, IMU data and the radar measurement range. Using Sigma-point Kalman filter prevents complete neglect terms of second or higher order, which would occur when the linearization of the measurement equation. Accounting for nonlinearities are important, especially for measurements using secondary radar due to the small distances between the user segment and transponder stations, as members of the second order in the ratio of the measured noise level without consequences cannot be neglected.

Sigma-point is iltr Kalman can be used to determine the correction data of the inertial navigation system of the pseudorange measurements of the GNSS receiver and the radar measurement range, and integrating the processor can execute the algorithm strapdown inertial navigation system (Strapdown-Algorithmus), which, based on the correction data and the measured inertial measurement unit movement of the device relative to the common axis of the coordinate system determines the three-dimensional position.

Alternatively, the Sigma-point Kalman filter can be performed to determine three-dimensional position based on the pseudorange measurements of the GNSS receiver, the radar measurement of range and INS navigation solution, and a certain three-dimensional position for calibration can be connected through a feedback system with inertial navigation system of the device.

First of all, the Sigma-point Kalman filter should not proceed from the linearization of slant range between the at least one radar antenna and one transponder, but also can take into account nonlinear terms, primarily members of the second order.

First of all, the slant range r can be approximated using the following nonlinear function, which also takes into account the members of the second order:

where

To solve the nonlinear filtering in nonlinear filter can be used optimization method for optimization can be used, first of all, the Sigma-point Kalman filter and the filter of the 2nd order.

Further, the non-linear filter can implement the state model, which depending on the application device has a linear or nonlinear equation of state.

The predominant use of the invention is its use on Board the aircraft for navigation when approaching landing in marginal areas where multiple transponders secondary radar base station of the secondary radar device.

Another object of the invention is a method of three-dimensional positioning of the aircraft, including:

- reception radar measurements range from installed on the aircraft base station of the secondary radar, which is designed for measuring the distance to a transponder and has at least one radar antenna

- receiving pseudorange measurements from installed on an aircraft GNSS receiver, which is designed to measure the GNSS signal and the GNSS has-receiving antenna,

- taking measurements move GNSS receiving antenna and at least one radar antenna from installed on an aircraft inertial measurement unit, which is designed to determine the position of the GNSS-receiving antenna, and at least one radar antenna in the related Letatlin the m machine the common coordinate system, and

- determination of the three-dimensional position of General control points by combining pseudorange measurements of the GNSS receiver, the radar measurement range, and the resulting inertial measurement unit measuring displacement GNSS receiving antenna and at least one radar antenna with offset shoulders defined by the distances from a common reference point to GNSS receiving antenna, at least one radar antenna and an inertial measurement unit. Compensation shoulders provides that in the end all measurements will be treated to the same anchor point. Compensation shoulders is required because the GNSS antenna, radar (radar) antenna (antenna), and an inertial measurement unit in the standard case of spatially separated.

The method can be implemented, for example, in the on-Board computer of the aircraft, such as aircraft or helicopter, which already have with a GNSS receiver and a GNSS antenna and an inertial measurement unit and, if necessary, the system of secondary radar. This allows you to equip and improve the existing flight navigation system, which when landing is assured of accurate and reliable three-dimensional positioning. The method can be implemented as software that can be executed in the on-Board computer is re.

Further, the method may differ in the following steps:

nonlinear filtering for determining the correction data of the INS navigation solution from the received pseudorange measurements and the received radar measurement of range, and

the algorithm strapdown inertial navigation system for determining the three-dimensional position based on the correction data and the received measurements of displacement or

nonlinear filtering for determining the three-dimensional position based on the received pseudorange measurements taken of the radar measurement of range, and adopted the INS navigation solution.

Nonlinear filtering can use the approximation slant range between the at least one radar antenna and the transponder through a nonlinear function, particularly in the case of quadratic functions, particularly in the case of approximation of slant range r using the following nonlinear functions:

where*
x _*

*- point approximation, where*$$\nabla r\left({\underset{\_}{x}}_{U,k}^{-}\right)$$ - private vector derivative of r at the point$${\underset{\_}{x}}_{U,k}^{-}$$ and where$$H\left({\underset{\_}{x}}_{U,k}^{-}\right)$$ the matrix is the second private derivative of r at the point$${\underset{\_}{x}}_{U,k}^{-}$$ .

*When nonlinear filtering to solve nonlinear filtering in nonlinear filter can be used nonlinear optimization method, first of all Sigma-point Kalman filter or a filter of the 2nd order.*

*The present invention according to the following form of execution refers to a computer program for performing the act is both according to one form of the present invention and a computer software product,
includes made with the possibility of machine readable media program, on which a computer program can be stored in the form of control signals from the electronic and/or optical reader.*

*The following advantages and possible applications of the invention result from the following description in conjunction with the drawings examples of execution.*

*In the description, claims, abstract and drawings are used in the bottom of the list of reference designations terms and the corresponding reference signs.*

*The drawings show*

*Figure 1 is an example system architecture of the device of the three-dimensional positioning according to the invention,*

*Figure 2 - availability and assignment of weights data from sensors in the user segment for glide path according to the invention,*

*Figure 3 - a combined approach for data from sensors secondary radar data GNSS receiver and IMU data from the sensors according to the invention, and*

*4 is a unified approach to data from sensors secondary radar data and GNSS receiver sensors, integrated navigation solutions inertial navigation system according to the invention.*

*In the following description, identical, functionally identical funkcjonalne interrelated elements can be provided with the same reference symbols.
Further, the absolute values are given only as examples, and should not be construed as limiting the invention.*

*The following describes the system architecture is based on secondary radar system of the three-dimensional positioning and the United nonlinear filtering based approach shown in figure 1, the device 10 for accurate three-dimensional positioning in a spatially limited region according to the invention. The architecture has a ground segment with the landing pad for the helicopter and the user segment, which is located on the helicopter.*

*System architecture*

*Ground and user segment of the device 10 for accurate three-dimensional positioning in a spatially limited area has the following elements:*

*1) Ground segment:*

*Variable number of transponders 14 secondary radar, the location of which can be agreed with the local conditions and the orientation of the antennas which can be optimized from the point of view of a particular application. Transponders can be located, for example, along the edges of the zone approach, figure 1 around helicopter landing pads 26, thus using radar to detect landing, especially in bad weather conditions, for example at ground fog.*

*2) User is Liski segment:*

a. The base station 12 secondary radar with at least one radar antenna 16, which can be optimized depending on the application in order to avoid shading of the radar signals and the effect of multiple lobes of radiation. Perhaps a seamless extension to two or more radar antennas. Although in the user segment can be applied also multiple radar antennas, the following descriptions to improve clarity comes from having a single radar antenna. Radiated by the base station radar signals (dotted lines in figure 1) pereklokayutsia transponders 14 ground segment in the form of a response signal.

b. GNSS (Global Navigation Satellite System) receiver 18 with a GNSS antenna 20. The GNSS receiver may be, for example, the receiver signals NAVSTAR-GPS, GLONASS or the future European GALILEO GNSS.

c. IMU (inertial measurement unit) 20 to determine the position of the GNSS receiving antenna and radar (radar) antenna (antennas) associated with the user segment coordinate system.

d. (Navigation) a computer 24, which is merging data from sensors and calculating a three-dimensional position of the user. The computer 24 also includes an integrating processor for data from the sensors using the above combined nonlinear what about the filter, which are described in detail next.

If the corresponding user segment in the standard implementation has additional sensors (e.g., altimeter), these additional data from the sensors can also be utilized to generate a solution positioning. Shown in figure 1 the structure of the sensors represents the minimum amount of devices in which the system 12, 14 of the secondary radar is a key component. Even in this minimal configuration, you can achieve quite good performance. In order to get the best results when modeling the delay time of the signal in the troposphere, it is possible to expand the temperature sensors, pressure and humidity.

The coordinates of the transponder antennas 14 in the absolute coordinate system of the user segment known that he could make good use of the measuring range of the radar in a nonlinear filter. Information about the coordinates of the transponders can either be statically stored in the memory of the user segment, or dynamically transmitted through the data line in the user segment. If the transponder 14 is located on a mobile platform, for example on the carrier, the absolute coordinates of the transponder must be dynamically adjusted.

The system 12, 14 secondary radar slave who melts in the C-band (IEEE) and to determine the range of uses FMCW (FMCW: Frequency Modulated Continuous Wave) - radar signals. Within the small to medium range from the transponder 14 ground segment at the base station 12 secondary radar user segment is available for accurate measurement of distance. Within this limited spatial region can be made highly accurate three-dimensional positioning. The task of positioning within the operating region is characterized by its high availability and continuity, as well as a very small integrated risk that will not be recognized unacceptably large positioning errors.

Along with the measurement range with a low noise level, the system 12, 14 secondary radar nonlinear filter are processed also GNSS pseudorange measurement with a higher noise level for the following reasons: secondary radar covers only a limited area of operations and, as a rule, is established only where, along with a small integrated risk requires high positioning accuracy, availability and continuity, figure 1 - the landing 26. Outside this area the requirements for solving the problem of positioning, as a rule, below. Using the appropriate invention device can improve the solution of the problem of three-dimensional positioning with approaching critical about erational region, such as shown in figure 1 helicopter landing 26. This concept is explained in figure 2 the sample path approach or glide path: Beyond the operating region 28 of the secondary radar (dotted line in figure 2) measurement range radar with a low noise level is not available, so the solution of the three-dimensional positioning is based solely on United (differential) GNSS/INS (Inertial Navigation System) navigation solution. Inside the operating region 28 is determined by the combined secondary radar/(differential) GNSS/INS navigation solution. This nonlinear filter for GNSS pseudorange measurements due to excessive dispersion measurements can be assigned significantly less weight than the radar measurement range, which have accordingly reduced the variance of the measurements.

In the operating region 28 of the secondary radar, that is, near the landing pad 26 in figure 1, the pseudorange measurement with a high level of noise still can be considered a nonlinear filter with a smaller weight coefficient, instead of treating only the measurement range of the radar with a low noise level. Therefore, the number of transponders 14 in the system can be maintained at a small level, and positioning are less susceptible to the absence of measurement is relevant between the base station 12 secondary radar and a separate transponders 14 from behind the shadows of the signal. If for positioning will be used solely measuring range of the radar, it may appear too large VDOPs (Vertical Dilution Of Precision) (error positioning vertical) due to the fact that the antenna of the transponder 14 and the radar antenna 16 user segment are approximately in the same plane. Combining measurements of the satellite signals and radar signals in the United filtering approach within the operating area out very good value HDOP (Horizontal Dilution Of Precision) (precision of positioning horizontally) and VDOP.

The user segment has three rotational degrees of freedom in space. For the concept of three-dimensional positioning requires knowledge of the angular position of a user segment, as on the user side using two spatially separated antennas (radar antenna 16 and a GNSS antenna 20 in figure 1) for GNSS signals and radar signals. The required information about the angles obtained by integrating IMU 20. Thus, GNSS measurements and radar measurements can be tied to a common zero or reference point due to the fact that will be compensated shoulder. Other positive aspects of using IMU 20 is that the inertial system has high availability, may b the th achieved high-speed data transmission, and can be found a complete solution of the navigation problem for all six degrees of freedom of the user segment.

United nonlinear filtering approach

To achieve highly accurate three-dimensional positioning on the side of the user combines the following data from the sensors. Based on the selected combination of sensors can be found a complete solution of the navigation problem, beyond just specifying a three-dimensional position. In order to combine data from sensors has led to a high-precision solution for positioning in the measuring model filter are taken into account spatial differences between the GNSS antenna position, position (position) radar (radar) antenna (antennas), and ISA (Inertial Sensor Assembly). Differences between the reference points of the sensor data (the phase center of the GNSS antenna phase center of the radar antenna, ISA) are defined when installing the system, for example, in the coordinates of the North-East-Down (NED). In the further description as a common reference point of the selected ISA, so after installation you specify both displacement vector

Below is a list of output data of the sensors separately. Processing some of the data is optional, so you can choose the filter between higher computational costs and increase productivity through the use of additional independent measurements.

System 12 secondary radar on the side of the user supplies resultfilename measurements:

- slant-range to the n transponders 14 ground segment,

- optional: the rate of change of the removal to the n transponders 14 ground segment,

- related to the measurement of quality factors and/or dispersion GNSS receiver 18 supplies the following values as sensor output:

- pseudodementia (slant range plus error) to m satellites

- optional: Doppler measurements to m satellites

- optional: ADR (Accumulated Doppler Range) to m satellites

- optional: differential correction data (e.g., SBAS), which are superimposed on the measurements of the GNSS receiver,

- standard deviation of the measurements.

IMU 22 supplies the measurement results for:

acceleration on the axis, the angular velocity on the axis.

Figure 3 shows the combined approach for data from the sensor secondary radar, GNSS receiver and IMU, where "initial" measurement of accelerations and angular rates from the IMU 22 are processed in integrating the processor 30. Measurement range, the dispersion of the measurements and, if necessary, measure the rate of change of range of the base station 12 secondary radar sends pre-filter 32 integrating data processor 30. Next, measure the pseudorange (PSR), the variance of the measurements and, if necessary, the differential correction data, ADR - measure the Oia and Doppler measurements are summarized in a preliminary filter 34 corrections and integrating data processor 30. The output of both filters 32 and 34 are summed in a non-linear filter 36 integrating processor 30, which on the basis of the measurement data and the INS navigation solution calculates correction data 38 for determining the three-dimensional positions are processed by the integrating processor 30 algorithm strapdown inertial navigation system. In the algorithm 38 strapdown inertial navigation system then adds the acceleration and angular velocity and, if necessary, dispersion measurements, which were measured by the IMU 22. These measured movement of the device 10 are also processed by the algorithm 38 strapdown inertial navigation system. As a result, the inertial processor 30, along with the three-dimensional position, may issue such additional data as the covariance, velocity, acceleration, position.

If the user IMU is integrated into the navigation computer, the INS navigation solution, as shown in figure 4 for the combined approach for data from sensors from the secondary radar and GNSS receiver, can be handled directly in integrating the processor 31. In the nonlinear filter 37 integrating processor 31 summarizes the filtered output of both filters 32 and 34, and a certain inertial navigation the system (INS) 23 three-dimensional position, speed, position, the matrix of covariance of the States and, if necessary, the acceleration of the device 10. Unlike shown in figure 3 approach, the nonlinear filter 37 on the basis of the received data determines no corrective data, and a three-dimensional position of the device 10, which generates an integrating processor 31, especially with such additional specific data, as of covariance, velocity, acceleration, position, time. Found the solution positioning is also used to support a separate inertial navigation system.

Next explained are both used in integrating the processors 30 and 31 ways to integrate data from sensors of the secondary radar, GNSS receiver and IMU in nonlinear filters 36 and 37. How you should use alternative to each other.

The nonlinear measurement model is used for measurements of the secondary radar because of the small distances between the user segment and transponder stations and rapidly changing geometry user/transponder operating region. Radar measurement range s_{k}between the transponder TR and the user U with a three-dimensional vector projection

with geometric slant range

When ν_{k}is measured by the level of noise in addition to these unadjusted their components the values,
as mnogonapravlennostj and the calibration error. R function at the current point approximation

*
k -*

*where $$\nabla r\left({\underset{\_}{x}}_{U,k}^{-}\right)$$the rector of a private derivative of r at the point$${\underset{\_}{x}}_{U,k}^{-}$$and$$H\left({\underset{\_}{x}}_{U,k}^{-}\right)$$the matrix of the second private derivative of r at the point$${\underset{\_}{x}}_{U,k}^{-}$$. For optimization can be used, for example, a filter of the 2nd order. To solve the existing problems of nonlinear filter is also well suited Sigma-point Kalman filter. In General, you should use a nonlinear optimization method to not proceed from a simple linearization of the equations of slant range.*

*Used in the model filter condition can be corrected with specific applications. Depending on the application of best suitability can show linear or nonlinear equation of state.*

*Uptime*

*The described method is reliable in terms of intentional killing, because not all the selected sensors simultaneously and equally influenced by one station is active jamming. While GNSS operates in L-band, the radar system is operated in C-band. The next significant difference is that the GNSS receiver in the user segment is passive, while the base station of the secondary radar in the user segment is the active component. Based on the high degree of duplication of measurements within critical operating region GNSS interference or radar system can Pro is th way to detect.
Next, the system reliability is increased by the application of the IMU, which is substantially impervious to the stations active jamming. The issue of integrating processor solving the problem of three-dimensional positioning is preceded by the integrity verification solution. Along with a clear recognition of error in integrating the calculator can also be implemented ways to eliminate the errors, thus achieving very high availability solutions positioning tasks.*

*By the present invention and forms of execution of the invention can be achieved, first of all, the following advantages:*

*along with high precision three-dimensional solution positioning is possible to simultaneously achieve high availability, continuity and integrity of solving the problem of positioning within a limited spatial region,*

*- there is a possibility of achieving a high speed upgrade solutions positioning tasks.*

*- the system is more reliable than other proposed systems for PALS (Precision Approach and Landing Systems) in relation to active suppression as a result of the amalgamation of data from sensors, which combines the different principles of measurement, and the United filtering approach.*

*positioning takes place independently h is the user side: integrity monitoring solution positioning can be performed directly in the user block.
It requires little effort from the operator, and does not require additional data transfer between the ground and user segment,*

*- small mechanical dimensions, low power consumption and low costs for the purchase and operation of additional local system, i.e. base stations of a secondary radar and transponder stations,*

*- GPS receivers and antennas, as well as IMU is already installed in many user segments of air transport, so that the user's extension is required only to the base station of the secondary radar antenna (the antenna). You can use the existing on-Board computers for implementation of the nonlinear filtering algorithms,*

*- ground segment of the secondary radar can easily be mounted on mobile platforms (e.g., aircraft carriers).*

*The invention has the potential to provide three-dimensional positioning solutions in a bounded spatial domain (for example, in the area of helicopter landing sites) with the required air traffic accuracy, availability and integrity. Thereby, it is possible to drastically minimize the risk of crashes, as well as to save time and costs so that you can perform an Autonomous landing in bad/missing visibility landing. To ensure redlagaemoe the invention is reliable in the presence of interference sources.*

Reference designations and abbreviations

10 | The device of the three-dimensional positioning |

12 | The base station of the secondary radar |

14 | Transponder secondary radar |

16 | The radar antenna |

18 | GNSS receiver/GNSS RX |

20 | GNSS-antenna |

22 | IMU |

23 | INS |

24 | The navigation computer |

26 | A helicopter landing pad |

28 | The operating region of the secondary radar |

30, 31 | Integrating processor |

32 | Preliminary data filter of the radar measurement of range |

34 | Pre-filter corrections and given the measurements of pseudorange |

36 | Nonlinear filter |

38 | The algorithm strapdown inertial navigation system |

FMCW | Frequency Modulated Continuous Wave/frequency-modulated radar CW |

GNSS | Global Navigation Satellite System/global satellite navigation system |

HDOP | Horizontal Dilution Of Precision/accuracy decrease horizontally |

IMU | Inertial Measurement Unit the inertial measurement unit |

INS | Inertial Navigation System/inertial navigation system |

ISA | Inertial Sensor Assembly/structure inertial sensors |

NED | North-East-Down/North-East-Down |

RX | Receiver |

SBAS | Satellite Based Augmentation System/based on additional satellites system |

VDOP | Vertical Dilution Of Precision/decrease vertical accuracy |

1. The us is the device (10) for three-dimensional positioning of the aircraft,
having a ground segment, which includes several transponders (14), and the user segment located on an aircraft and includes:

base station (12) secondary radar, which is designed for measuring the distance to a transponder (14) and has at least one radar antenna (16),

- GNSS receiver (18), which is designed to measure the GNSS signals, and has a GNSS reception antenna (20),

- inertial measurement unit (22), which is designed to determine the position of the GNSS-receiving antenna, and at least one radar antenna in the related aircraft General coordinate system, and

integrates the processor (24, 30, 31), which summarizes measurements of pseudorange GNSS receiver, the radar measurement of range, and the measured inertial measurement unit (22) move GNSS receiving antenna and at least one radar antenna relative to the axis of a common coordinate system, which defines the three-dimensional position of General control points by combining the summed measurements and data, while taking into account measured GNSS receiving antenna and at least one radar antenna is compensation shoulders defined by the distances from a common reference point to GNSS receiving antenna, at least one radar antenna and an inertial who smertelnogo block.

2. The device according to claim 1, characterized in that the base station (12) secondary radar is made to operate in C-band (IEEE) and use FMCW radar signals to measure the distance.

3. The device according to claim 1 or 2, characterized in that is provided by the inertial navigation system (23), which has an inertial measurement unit (22), and integrating the processor (24, 30, 31) is made to run outside the operating region (28) of the system of secondary radar three-dimensional positioning of the aircraft with first United navigation-based pseudorange measurements of the GNSS receiver (18) and inertial navigation measurements inertial navigation system (23), and to perform within the operating region (28) of the base station (12) secondary radar three-dimensional positioning of the aircraft with the second joint navigation on the basis of the radar measurement of range, pseudorange measurements of the GNSS receiver (18), and inertial navigation measurements inertial navigation system (23).

4. The device according to claim 1, characterized in that the integrating processor (24, 30, 31) has a non-linear filter (36, 37) for processing the pseudorange measurements of the GNSS receiver, IMU data, and the radar measurement range.

5. The device according to claim 4, characterized in that there is a nonlinear filter, the (36) for determining the correction data of the INS navigation solution from the pseudorange measurements of the GNSS receiver and the radar measurement range, and integrating the processor (30) performs the algorithm strapdown inertial navigation system based on the correction data and the measured inertial measurement unit (22) moves the device relative to the common axis of the coordinate system determines the three-dimensional position.

6. The device according to claim 4, characterized in that the non-linear filter (37) is performed for determining the three-dimensional position based on the pseudorange measurements of the GNSS receiver, the radar measurement of range, and the INS navigation solution, and a certain three-dimensional position calibration is combined on the feedback channel with inertial navigation system (23) of the device.

7. The device according to claim 4, characterized in that the non-linear filter (36, 37) approximates the inclined distance between the at least one radar antenna (16) and a transponder (14) through a nonlinear function, primarily in the special case of quadratic functions, particularly in the case of slant range r is approximated using the following nonlinear functions:

where

8. The device according to claim 7, characterized in that the non-linear filter (36, 37) for the solution of nonlinear problems of filtering optimizes a nonlinear optimization method, first of all Sigma-point Kalman filter or a filter of the 2nd order.

9. Device according to one of claims 4 to 8, featuring the be fact, that the non-linear filter (36, 37) implements the state model, which depending on the application device has a linear or nonlinear equation of state.

10. Method three-dimensional positioning of the aircraft, including:

- reception radar measurements range from installed on the aircraft base station (12) secondary radar, which is designed for measuring the distance to a transponder (14) and has at least one radar antenna (16),

- receiving pseudorange measurements from installed on an aircraft GNSS receiver (18), which is designed to measure the GNSS signal and the GNSS has-receiving antenna (20),

- taking measurements move GNSS receiving antenna and at least one radar antenna from installed on an aircraft inertial measuring unit (22), which is designed to determine the position of the GNSS-receiving antenna, and at least one radar antenna in the related aircraft General coordinate system, and

- determination of the three-dimensional position of General control points by combining pseudorange measurements of the GNSS receiver, the radar measurement range, and the resulting inertial measurement unit measuring displacement GNSS receiving antenna and at least one radar antenna based compensation the AI shoulders,
defined distances from a common reference point to GNSS receiving antenna, at least one radar antenna and an inertial measurement unit.

11. The method according to claim 10, characterized in that it performs the following steps:

nonlinear filtering (36) for determining the correction data of the INS navigation solution from the received pseudorange measurements and the received radar measurement of range, and

- implementation of the algorithm (38) strapdown inertial navigation system for determining the three-dimensional position based on the correction data and the received measurements of displacement or

nonlinear filtering (37) for determining the three-dimensional position based on the received pseudorange measurements taken of the radar measurement of range, and adopted the INS navigation solution.

12. The method according to claim 10 or 11, characterized in that the non-linear filtering (36, 37) includes an approximation of the slant range between the at least one radar antenna (16) and a transponder (14) through a nonlinear function, particularly in the case of quadratic functions, primarily in the special case of approximation of slant range r using the following nonlinear functions:

where