A rangefinding method for determining the location and components of the velocity vector of objects using radio signals from spacecraft of satellite radio navigation systems. Rangefinder method Location methods

Based on the totality of measured geometric parameters, the system for determining the location of EMR sources is divided into:

· triangulation (goniometer, direction finding);

· difference-rangefinders;

· angular-difference-rangefinders.

The type and number of measured geometric quantities determine the spatial structure of the system for determining the location of the EMR source: the number of spatially separated receiving points of EMR source signals and the geometry of their location.

The triangulation (goniometer, direction finding) method is based on determining directions (bearings) to the EMR source at two points in space using radio direction finders spaced at base d (Fig. 18, a).

Rice. 18. Explanation of the triangulation method for determining the location of the EMR source on the plane (a) and in space (b)

If the EMR source is located in a horizontal or vertical plane, then to determine its location it is enough to measure two azimuth angles μ1 and μ2 (or two elevation angles). The location of the EMR source is determined by the intersection point of straight lines O1I and O2I - two position lines.

To determine the location of the source in space, measure the azimuth angles qa1 and qa2 at two spaced points O1 and O2 and the elevation angle qm1 at one of these points or, conversely, the elevation angles qm1 and qm2 at two receiving points and the azimuth angle qa1 at one of them (Fig. 18, b).

By calculation, the distance from one of the receiving points to the source can be determined using the measured angles and the known base value d:

from here we equate two expressions for h:

Thus, the distance to the source

The triangulation method is easy to technically implement. Therefore, it is widely used in radio and RTR systems, in passive radar diversity systems for detecting and determining the coordinates of emitting objects.

A significant disadvantage of the triangulation method is that with an increase in the number of EMR sources located in the coverage area of ​​radio direction finders, false detections of non-existent sources may occur (Fig. 19). As can be seen from Fig. 19, along with determining the coordinates of three true sources I1, I2 and I3, six false sources LI1, ..., LI6 are also detected. False detections can be eliminated when using the triangulation method by obtaining redundant information about direction-finding sources - by increasing the number of spaced radio direction finders or by identifying the received information as belonging to a specific source. Identification can be carried out by comparing signals received by direction finders by carrier frequency, repetition period and pulse duration

Rice. 19.

Additional information about sources is also obtained through cross-correlation processing of signals received at spaced points in space.

Elimination of false detections when using the triangulation method is also possible by obtaining data on the difference in distances from the radiation source to receiving points (locations of radio direction finders). If the point of intersection of the bearing lines does not lie on the hyperbola corresponding to the range difference, then it is false.

The difference-range-measuring method of location determination is based on measuring, using RES, the difference in distances from the EMR source to receiving points separated in space by a distance d. The location of the source on the plane is found as the intersection point of two hyperbolas (two range differences measured at three receiving points) belonging to different bases A1A2, A2A3 (Fig. 20). The focal points of the hyperbolas coincide with the locations of the reception points.

Rice. 20.

The spatial position of EMR sources is determined by three range differences, measured at three to four receiving points. The source location is the intersection point of three hyperboloids of revolution.

The goniometer-difference-rangefinder method of location determination involves measuring, using RES, the difference in distances from the EMR source to two spaced receiving points and measuring the direction to the source at one of these points.

To determine the coordinates of the source on the plane, it is enough to measure the azimuth μ and the difference in the ranges of the arterial pressure from the source to the receiving points. The location of the source is determined by the intersection point of the hyperbola and the straight line.

To determine the position of the source in space, it is necessary to additionally measure the elevation angle of the EMR source at one of the receiving points. The source location is found as the intersection point of the two planes and the surface of the hyperboloid.

Errors in determining the location of an EMR source on a plane depend on the errors in measuring two geometric quantities:

· two bearings in triangulation systems;

· two range differences in difference rangefinder systems;

· one bearing and one range difference in angular-difference-rangefinder systems.

With a centered Gaussian law of distribution of errors in determining position lines, the root-mean-square value of the error in determining the location of the source is:

where are the variances of errors in determining position lines; r is the cross-correlation coefficient of random errors in determining the position lines L1 and L2; r - angle of intersection of position lines.

For independent errors in determining position lines, r = 0.

With the triangulation method of determining the location of the source

Root Mean Square Position Error

When using identical direction finders

The greatest accuracy will be when the position lines intersect at right angles (r = 90°).

When assessing errors in determining the location of a source in space, it is necessary to consider measurement errors of three geometric quantities. The location error depends in this case on the relative spatial orientation of the position surfaces. The highest accuracy of position determination will be when the normals to the position surfaces intersect at right angles.

The invention relates to the field of radio engineering, namely to radio monitoring systems for determining the coordinates of the location of radio emission sources (ERS). The achieved technical result is a reduction in hardware costs. The proposed method is based on receiving RES signals by antennas, measuring the difference in the time of signal reception from RES at several points in space by scanning radio receivers, converted into a system of equations, and is also based on the use of two identical, stationary radio monitoring posts (RP), one of which is taken as the leading one , connecting to another communication line, while calibrating the meter of the delay value of the arrival of signals at (RP), using reference radio electronic equipment (RES) with known signal parameters and location coordinates, then quasi-synchronous scanning and measurement of signal levels at specified fixed tuning frequencies is carried out at the RP and the amount of delay in the arrival of RES signals. Information from the slave RP is transmitted to the master, where the level ratio and the difference in the arrival delay of the RES signals are calculated, taking into account the results of the calibration of the meters, and two equations for the position of the RES are compiled, each of which describes a circle with a radius equal to the distance from the RP to the RES. Distances are determined through the ratio of signal levels and the difference in signal reception time measured at the RP using only one pair of antennas with a known azimuth of the main lobe axis and radiation pattern, the main lobe of each of which is located in different half-planes relative to the base line, and the coordinates of the IR are determined by a numerical method of solving the compiled equations, taking as true only the coordinates related to the half-plane relative to the base line in which the main lobe of the antenna with the highest level of the received signal is located. The device implementing the method contains two identical RPs, one of which is the master, and at each station contains directional antennas, a measuring scanning radio receiver, a signal arrival delay meter, a computer and a communication device connected in a certain way. 2 n.p. f-ly, 2 ill.

Drawings for RF patent 2510038

The invention relates to the field of radio engineering, namely to radio monitoring systems for determining the coordinates of the location of radio emission sources (ERS), information about which is not in the database (for example, the state radio frequency service or the state communications supervision service). The invention can be used in searching for the location of unauthorized means of communication.

There are known methods for determining the coordinates of PRIs, in which at least three passive direction finders are used, the center of gravity of the area of ​​intersection of the identified azimuths at the wave arrival front is taken as an estimate of the location. The main operating principles of such direction finders are amplitude, phase and interferometric. A widely used method is the amplitude direction finding method, which uses an antenna system that has a radiation pattern with a pronounced maximum of the main lobe and minimal back and side lobes. Such antenna systems include, for example, log-periodic or antennas with a cardioid characteristic, etc. With the amplitude method, mechanical rotation is used to achieve the antenna position at which the output signal has a maximum value. This direction is taken as a direction to Iran. The disadvantages of most direction finders include the high degree of complexity of antenna systems, switching devices and the presence of multi-channel radio receivers, as well as the need for high-speed information processing systems.

The presence in the federal districts of the state radio frequency service of radio control posts interconnected through the central point of an extensive network, equipped with means of receiving radio signals, measuring and processing their parameters, makes it possible to supplement their functions with the tasks of determining the coordinates of the location of those radioactive sources, information about which is not in the database, without resorting to the use of complex and expensive direction finders.

There is a known method in which to determine the coordinates of the RES location, N, at least four, stationary radio control posts are used, located not on the same straight line, one of which is taken as the base one, connecting with the remaining N-1 posts by communication lines, quasi-synchronous scanning is carried out at all posts at given fixed tuning frequencies, average the measured values ​​of signal levels at each of the scanned frequencies, and then at the base post for each of the C 4 N combinations (combinations of N by 4) based on the inversely proportional relationship between the distance ratios from the post to the radio source and the corresponding Based on the differences in signal levels, expressed in dB, three equations are made, each of which describes a circle of equal ratios, based on the parameters of any two pairs of which they determine the current average value of the latitude and longitude of the location of the radio emission source. The disadvantage of this method is the large number of stationary radio monitoring posts.

Direction finding methods and devices are known (4, 5), which can be used for the purpose of determining coordinates.

Method (4) is based on receiving signals by three antennas, forming two pairs of measuring bases, measuring the differences in the arrival times of RES signals and deterministic calculations of the desired coordinates.

The disadvantages of this method include:

1) A large number of antennas.

2) The method is not focused on the use of radio control posts.

3) Measuring bases for calculating the difference in arrival times of signals with pairs of antennas significantly limit the spacing of these antennas, not to mention the inexpediency and great technical complexity of implementing the method.

A spaced difference-range direction finder (5), consisting of two peripheral points, a central one and a single time system, aims to relieve the communication channel between points. Peripheral points are designed to receive, store, process signals and transmit signal fragments to the CPU, where the difference in signal arrival time is calculated. The unified time system uses a chronicler, which is a keeper of the current time scale (clock) tied to the unified time scale, designed to link the signal level values ​​​​recorded in the memory to the reception time value.

This direction finder has the following disadvantages:

1) Not adapted to radio control points used in branches of the federal districts of the state radio frequency service or the state communications supervision service.

2) A large number of specialized direction-finding (but not radio control) posts.

3) Unfounded and not disclosed (at least until functional diagram) the use of a unified time system on the CPU and chronicizers on the PP, synchronized with the unified time system.

4) The need for radio channels with high bandwidth (up to 625 Mbaud) to transmit even fragments of signals from PP1 and PP2 to the CPU.

5) To organize a radio channel, radio transmitting devices and obtaining permission to operate them under certain operating conditions are required.

There is a known difference-rangefinder method for determining the coordinates of a radio emission source and the device that implements it (6).

A method based on the reception of RES signals by four antennas forming three independent measuring bases at spaced points A, B, C, D in such a way that the volume of the figure formed from these points is greater than zero (V A,B,C,D >0 ). The signal is simultaneously received by all antennas; three independent time differences t AC, t BC, t DC of signal reception by pairs of antennas forming the measuring antenna bases (AC), (BC) and (DC) are measured. Based on the measured time differences, the distance differences from the IR to pairs of points (A, C), (B, C), (D, C) are calculated, for k-th triple antennas located at points A, B, C at k=1, B, C, D at k=2, D, C, A at k=3, the angle values ​​k characterizing the angular position of the position plane are calculated using the measured range differences RES k , k=1, 2, 3 relative to the corresponding measuring base, and the coordinates of point F k belonging to the k-th plane of RES position, calculate the required coordinates of RES as the coordinates of the intersection point of three planes of RES position k , k=1, 2, 3 each of which is characterized by the coordinates of points location k-th antenna triples and the calculated values ​​of the angle k and the coordinates of the point F k , display the results of calculating the coordinates of the RES in a given format.

This method and the device that implements it are closer to the claimed one, but also have a number of significant disadvantages:

1) The complexity of the practical implementation of the method due to the inability to measure the differences in the time of reception of the RES signal only by antennas (measuring radio receivers are absent in the block diagram).

2) The need to bring RES signals from EMD antennas spaced at an optimal distance of 0.6-0.7 R according to (2) to one point, which is practically impractical to implement.

3) It is very difficult to measure the difference in the time of reception of the RES signal at specific given frequencies directly from antennas (without using radio receivers, which are not shown in the block diagram).

4) To measure the difference in signal reception time directly from antennas, two-input meters are used.

5) The complexity of technical implementation due to the large number of different computers.

6) Uncertainty in constructing the position surface in the form of a plane perpendicular to the plane of the antennas, since the antennas at points A, B, C, D are not located in the same plane, as evidenced by the condition V A, B, C, D > 0 in the claims .

The closest to the claimed is the rangefinder-difference-rangefinder method for determining the coordinates of a radio emission source and the device (7) that implements it, adopted as a prototype.

The method is based on receiving a signal by three antennas, measuring the values ​​of two differences in the times of reception of the RES signal by the antennas, measuring two values ​​of the power flux density of the RES signal, and subsequent processing of the measurement results in order to calculate the coordinates of the point through which the position line of the RES passes.

This method involves performing the following operations:

Three antennas are located at the vertices of triangle ABC;

Receive the signal on all three antennas;

Two differences in the times t AC and t BC of reception of the RES signal by antennas are measured;

The power flux densities P 1 and P 2 of the signal are measured at the locations of antennas 1 and 2;

Calculate the values ​​of the differences in ranges from the RES to pairs of antennas using the expressions r AC =C t AC, r BC =C t BC, r AB = r AC - r BC, where C is the speed of propagation of the electromagnetic wave;

Calculate the coordinates using the resulting formula.

In accordance with (7), the device implementing the method includes:

Three antennas;

Two time difference meters;

Two power flux density meters;

Computing unit;

Display block.

The prototype has the following disadvantages:

1) The practical complexity of implementing the method due to the inability to measure the differences in the time of reception of the RES signal only by antennas (measuring radio receivers are absent in the block diagram).

2) The need to combine RES signals from antennas spaced several kilometers apart to one point for measurement with two-input meters, which is a significant problem that has not been solved by the authors of the patent.

3) Not adapted to the equipment of radio control posts (two time difference meters, two power flux density meters, a computing unit, an indication unit) available in the branches of the federal districts of the radio frequency service of the Russian Federation are redundant, and therefore cannot be used there.

4) Applicable receiving antennas can only be isotropic, since the formulas for calculating coordinates do not contain the parameters of their directional patterns.

The purpose of the present invention is to develop a method for determining the coordinates of the location of radioactive sources by two radio control posts, which will make it possible to apply this method in almost all branches of the federal districts of the Radio Frequency Service of the Russian Federation.

This goal is achieved using the features specified in the claims, common to the prototype: a method for determining the coordinates of the location of radio emission sources, based on the reception of irradiation signals by antennas, measuring the levels and time difference of signal reception from irradiation sources at several points in space by scanning radio receivers and converted into a system equations, and distinctive features: to determine the coordinates of the location of the RES, two identical stationary radio control posts are used, one of which is taken as the leader, connecting to the other by a communication line, the meter of the delay value of the arrival of signals at the posts is calibrated using standard RES with known signal parameters and location coordinates , then at the posts they carry out quasi-synchronous scanning and measurement of signal levels at given fixed tuning frequencies and the amount of delay in the arrival of PR signals, and then transfer them to the base post, where they calculate the level ratio and the difference in the arrival delay of RES signals, taking into account the results of calibration of the meters, and also compile two equations for the position of the RES, each of which describes a circle with a radius equal to the distance from the post to the RES, and these distances are determined through the ratio of signal levels and the difference in signal reception time, measured at posts using only one pair of antennas with a known azimuth of the main lobe axis and diagram directionality, and the coordinates of the RES are determined by a numerical method of solving the compiled equations. The inventive method is illustrated by drawings, which show:

In Fig.1 - the placement of two radio monitoring posts and the position of the RES, E - true position, Ef - fictitious; a, b - angles of position of the axis of the main lobe of the bottom; AB - base line; AE, BE - lines of azimuths a and b to the true position of the IRE; AEf, VEf - lines of azimuths af and bf to the fictitious IRE;

Figure 2 is a block diagram of the implementation of the proposed method,

The proposed method involves performing the following operations:

1) Calibrate the signal arrival delay meter (SAR) at the posts using an array of reference RES with known signal parameters and location coordinates. Each reference RES must be located in the EMD zone of both posts. Their number and distribution in the EMD zone must be sufficient to ensure the specified calibration accuracy both in distance and azimuth from the posts.

2) At each post, signal levels are measured using a radio receiver and the delay in the arrival of RES signals using an appropriate meter, using post antennas with a known radiation pattern, while tuning the receiver to specified fixed frequencies. The procedure for measuring the delay values ​​of the arrival of RES signals is carried out similarly to step 1. The results are entered into the data bank of your computer.

3) Send information from the slave computer to the master computer via the communication channel of the communication device.

4) Calculate the difference in the delay values ​​of the arrival of signals to the antennas of the posts both from the reference RES and from the RES, taking into account the results according to claim 1, and also calculate the ratio of the levels of signals from the RES, measured by the radio receivers of the posts.

5) Compose a system of two equations that determine the position of the IRE, and solve it numerically using the data from point 4.

The position equations will then have the form of circles

where: r a, r b are the distances from the posts to the desired RES, and 8 is their difference (Fig. 1).

We write the squares of the radius ratios in terms of the measured signal levels as

The ratio of the squares of the distances, determined through the difference in signal levels measured at radio monitoring posts A and B and expressed in dB, allows us to describe the position line of the PXR, while eliminating the dependence of this position line on the power of the desired source of radio emission. In this case, from (3), based on the calculated difference in distances, the squares of distances are determined in the form:

And .

Since the circles intersect at two points symmetrical with respect to the base line (see Fig. 1), ambiguity arises in the coordinates of the IRI. To remove the resulting ambiguity, repeated measurements can be performed using a directional (with a known beam pattern), for example, log-periodic or cardioid rotary antennas. But this option is associated with large time costs and complexity of automating such a solution. In the inventive method, determination of the coordinates of the RES with simultaneous elimination of ambiguity is carried out by measuring signal levels directly to the directional antennas. In this case, the directional antennas do not rotate in the direction of the maximum emitted signal, but the position of the axis of its main lobe at both posts must be known, and the lobes are oriented in approximately opposite directions relative to the base. This position of the axes of the main lobes of the antennas is shown in Fig.1. The dependence of the EMF at the antenna output E() is related to the field strength near it and the angle that determines the position of the axis of the main lobe of the bottom beam relative to the azimuth at the PXR, can be represented as E() = Em (), where Em is the maximum EMF corresponding to the direction of the main axis lobe to the source, () - a function that determines the antenna diagram. Now the ratio of signal levels for directional antennas n (a, b) can be represented in terms of the ratio of levels received from omnidirectional antennas n ab as, where

And - function of DNA relations.

Hence n ab =n( a , b)/ ( a , b) and the squares of the radii (4) of system (1) will be presented in the form:

To solve the system of equations (1) and (2), taking into account (5) and (6), it is necessary to determine the angles a, b and know (). From Fig. 1 they are defined as a = a - a, b = b - b, ,

where: af = af - a, bf = bf - b, a< /2, то ИРИ находится во второй полуплоскости (ниже линии базы). При априорно снятой неопределенности расположения ИРИ относительно линии базы (например, при выполнении операции поиска ИРИ силовыми структурами) применяют ненаправленную (например, штыревую или биконическую антенны) и вычисление координат ведут по формулам (1), (2) с учетом (3) и (4).

The composition of the inventive device that implements the inventive method includes two identical radio control posts - RKP A and RKP B, containing:

1. Antennas 1, 6;

2. Radio receivers (RP) 2, 7;

3. Meters of signal delay values ​​(IVZ) 3, 8;

4. Computers 4, 9;

5. Communication devices 5, 10.

One of the posts (for example, let this be post RKP A) is the leader. The outputs of the antennas 1, 6 are connected to the inputs of scanning radio receivers 2, 7, control computers 4, 9 are connected by bidirectional connections with a communication device 5, 10, intended for transmitting information, scanning receivers 2, 7 and meters of the delay in the arrival of signals 3, 8, input each of which is connected to the output of the corresponding scanning receiver. The RES signals measured by the receivers are sent via bidirectional communication to the computer at the corresponding post. In blocks 3, 8, the delay value of the arrival of signals from both reference RES to create a calibration file used in calculating coordinates, and RES signals is measured and the measured values ​​are transmitted at the request of the computer to its database. Under the control of the master post computer, all information from the slave post is transmitted via the communication channel of the communication device 5, 10 to the master post computer. There, the coordinates are calculated using the equations for the position of the RES, taking into account the radiation patterns of the antennas and calibration files. Coordinate calculations are carried out using the numerical method of successive approximations. Thus, the proposed method allows you to determine the coordinates of the RES in contrast to the prototype:

1) only two stationary radio monitoring posts;.

2) the RES signal is received only by two antennas;

3) directional antennas with pronounced maxima of the radiation pattern are used, and not with a circular radiation pattern;

4) measurement of the delay values ​​of the arrival of signals at the antennas of the posts is carried out at the location of the antennas with a single-input meter, using not the signals from the antenna outputs directly, but using amplified and filtered signals from the outputs of radio receivers;

5) the calculation of the difference in the measured signal arrival delay values ​​is carried out not by a two-input meter connected to the output of spaced antennas, but on one computer of the leading post using calibration files obtained by measurement;

6) the main lobe of each antenna is located in different half-planes relative to the base line. taking as true only the coordinates related to the half-plane relative to the base line in which the main lobe of the antenna with the highest level of the received signal is located.

7) calculation of location coordinates is carried out using a numerical method;

8) when the uncertainty of the location of the RES relative to the base line is a priori removed, an omnidirectional antenna is used (for example, a whip or biconical antenna) and the coordinates are calculated using formulas (1), (2) taking into account (3) and (4). This simplifies the implementation of the device using the proposed method

Such features have not been identified either in analogues or in the prototype and indicate the presence in the proposed invention of signs of novelty and an appropriate level of ingenuity.

Literature.

1. Korneev I.V., Lenzman V.L. and others. Theory and practice of state regulation of the use of radio frequencies and radio electronics for civil use.

Collection of materials for advanced training courses for specialists at radio frequency centers in federal districts. Book 2. - St. Petersburg: SPbSUT. 2003.

2. Lipatnikov V.A., Solomatin A.I., Terentyev A.V. Radio direction finding. Theory and practice. St. Petersburg VAS, 2006 - 356 p.

3. Method for determining the coordinates of the location of radio emission sources. Application No. 2009138071, publ. 04/20/2011 B.I. No. 11. Authors: Loginov Yu.I., Ekimov O.B., Rudakov R.N.

4. Difference-rangefinder method of direction finding of a radio emission source. RF patent No. 2325666 C2. Authors: Saibel A.G., Sidorov P.A.

5. Spaced difference-range direction finder. RF patent No. 2382378, C1. Authors: Ivasenko A.V., Saibel A.G., Khokhlov P.Yu.

6. Difference-rangefinder method for determining the coordinates of a radio emission source and the device that implements it. RF Patent No. 2309420. Authors: Saibel A.G., Grishin P.S.

7. Rangefinder-difference-rangefinder method for determining the coordinates of a radio emission source and the device that implements it. RF Patent No. 2363010, C2, publ. 10/27/2007 Authors: Saibel A.G., Weigel K.I.

CLAIM

1. A method for determining the coordinates of the location of radio emission sources (RS), based on measuring the levels and difference in the time of arrival of the signal from the RS to spaced antennas by scanning radio receivers and converted into a system of equations, characterized in that two stationary radio monitoring posts are used, one of which is taken as the leader, connecting with another communication line, calibrates the meter of the delay value of the arrival of signals at the posts, using standard radio-electronic means with known signal parameters and location coordinates, at the posts they carry out quasi-synchronous scanning to identify irradiated radiation, and then measure the signal levels at given fixed tuning frequencies and the delay values ​​of the arrival of the RES signals, transmitting them to the leading post, where the level ratio and the difference in the delay of the arrival of the RES signals are calculated using the results of calibration of the meters, and also two equations are drawn up, each of which describes a circle with a radius equal to the distance from the post to the RES, and these distances are determined through the ratio of signal levels and the difference in signal arrival delay values ​​measured at posts using only one pair of antennas with known azimuth of the main lobe axes and radiation patterns, the main lobe of each of which is located in different half-planes relative to the base line, and the coordinates of the IR are determined using a numerical method for solving the compiled equations, taking as true only the coordinates related to the half-plane relative to the base line in which the main lobe of the antenna with the highest level of the received signal is located.

2. A device for determining the coordinates of the location of radio emission sources, containing posts connected by bidirectional communication lines, including receiving antennas, scanning radio receivers controlled by a computer, characterized in that it contains two identical radio control posts, one of which is the master, and at each post a meter the magnitude of the signal arrival delay, and the outputs of the antennas are connected to the inputs of the scanning radio receivers, the control computer is connected by bidirectional connections to the communication device, the scanning receiver and the signal arrival delay value meter, the input of which is connected to the output of the scanning receiver.

Radiotechnical methods of external trajectory measurements

Equipment for external trajectory measurements, based on the radio engineering principle, has a greater tracking range and is more universal compared to optical equipment. It allows you to determine not only the angular coordinates of the aircraft, but also the distance to the object, its speed, direction cosines of the range line, etc.

Ranging in radio engineering systems comes down to determining the delay time t D arrival of emitted or reflected radio signals that are proportional to the range

D=ct D ,

Where With=3×10 8 m/s - speed of propagation of radio waves.

Depending on the type of signal used, the definition t D can be carried out by measuring the phase, frequency or direct time shift relative to the reference signal. The greatest practical application has been found pulse (temporary) And phase methods. In each of them, range measurement can be carried out as unsolicited, so request way. In the first case, the range D=ct D, in the second - D=0.5ct D .

At request-free pulse method High-precision timers are installed on board the aircraft and on the ground x 1 And x 2, synchronized before launch (Fig. 9.5). According to impulses u 1 chronicler x 1 onboard transmitter P emits pulse signals with a period T. Ground receiving device Etc accepts them through t D =D/c. Interval t D between pulses of the ground chronicizer u 2 and impulses u 1 at the receiver output corresponds to the measured range.

At request pulse method the signal is sent by a ground transmitter, received by an onboard receiver and relayed back.

Rice. 9.5. The principle of range measurement using a pulse-free method.

The accuracy of these methods increases with increasing pulse frequency.

Phase method range measurement is that the signal delay is determined by the phase shift between the request and response signal (Fig. 9.6).

Rice. 9.6. Phase ranging method

The ground transmitter emits vibrations:

u 1 =A 1 sin(w 0 t+j 0)=A 1 sinj 1 ,

Where A 1- amplitude,

w 0- circular frequency,

j 0- initial phase,

j 1 - signal oscillation phase.

On-board equipment relays the signal u 1, and the ground receiver receives the signal

u 2 =A 2 sin=A 2 sinj 2 ,

Where j A- phase shift caused by the passage of a signal in the equipment, determined by calculation or experiment.

Changing the phase of signal oscillations u 2 relatively u 1 is determined by the relation:

j D =j 2 -j 1 =w 0 t D =LpD/(T 0 s),

where is the range from?

Where l 0- wavelength.

When measuring angular motion parameters Amplitude and phase methods are most widely used in aircraft radio engineering.

Amplitude method is based on a comparison of signal amplitudes at different positions of the transmitting or receiving antenna. In this case, two options for implementing goniometric systems are possible: amplitude direction finders and beacons. In the first case, the transmitting device P is located on the aircraft, and the radiation pattern of the ground receiving device Etc periodically occupies position I or II (Fig. 9.7).

Rice. 9.7. Amplitude method for measuring angular parameters

If the angle a=0, then the signal level at both positions of the radiation pattern will be the same. If a¹0, then the amplitudes of the signals will be different, and from their difference the angular position of the aircraft can be calculated.

In the case when information about the angular position must be located on board the aircraft, use amplitude beacon. To do this, a transmitter is installed on the ground, and the radiation pattern of the ground antenna is scanned, periodically occupying positions I and II. By comparing the amplitudes of the signals received by the onboard receiver, the angular position of the aircraft is determined.

Phase method based on measuring the difference in distances from the aircraft to two reference points O 1 And O 2(Fig. 9.8).

Rice. 9.8. Phase method for determining angular parameters

In this case, the distance to the object R 1 And R 2 determined by phase difference DJ harmonic oscillations emitted by a source located at points O 1 And O 2. Cosine of direction angle q defined:

Where IN- distance between points O 1 And O 2.

An example of a complex of external trajectory measurements used in field practice is the “Track” system (Fig. 9.10). This equipment, developed and produced by the SKB measuring equipment NTIIM, uses the coordinate-goniometer-basic principle.

It consists of two tracking television theodolites 1, a control system 2, a unified time synchronization system 3, a recording and information processing system 4. The “Track” system allows you to receive information about coordinates, speed, drag coefficient, and also observe the behavior of an object on the monitor screen .

Rice. 9.10. System of external trajectory measurements “Track”:

1-tracking television theodolite; 2-control system; 3-unit time synchronization system; 4-systems for recording and processing information

The main characteristics of the “Track” system are given below:

Error in measuring angular coordinates at an elevation angle of up to 60 degrees:

Static - 15 arcsec

In dynamics - 30 arcsec,

Maximum object tracking parameters

Angular speed - 50 degrees/sec,

Angular acceleration - 50 degrees/sec 2,

The frequency of recording the angular coordinates of object images is 25-50 frames/sec.

The most important task of external ballistic research is to determine the spatial location of the aircraft’s center of mass, which is uniquely determined by three spatial coordinates. In this case, navigation uses the concepts of surfaces and position lines.

Under position surface understand the geometric location of the aircraft's location points in space, characterized by a constant value of the measured navigation parameter (for example, elevation angle, azimuth angle, range, etc.). Under position line, understand the intersection of two position surfaces.

The position of a point in space can be determined by the intersection of two position lines, three position surfaces, and a position line with a position surface.

In accordance with the type of measured parameters, the following five methods for determining the location of an aircraft are distinguished: goniometer, rangefinder, total and difference-rangefinder and combined.

Goniometer method is based on the simultaneous measurement of aircraft sighting angles from two different points. It can be based on both optical and radio engineering principles.

At cinetheodolite method application surface at a=const is a vertical plane, and the position surface at b=const- a circular cone with its apex at point O (Fig. 9.11, a).

Rice. 9.11. Determination of object coordinates using the film theodolite method,

a) surface and position line, b) coordinate determination scheme

Their intersection determines the line of position coinciding with the generatrix of the cone. Therefore, to determine the location of the aircraft, it is necessary to determine the coordinates of the point of intersection of two position lines OF 1 And OF 2(Fig. 9.11, b), obtained simultaneously from two measuring points O 1 And O 2.

In accordance with the scheme under consideration, the coordinates of the aircraft are determined by the formulas:

Where IN- distance between measuring points,

R- radius of the Earth in a given area.

Using rangefinder method aircraft coordinates are determined by the intersection point of three spherical position surfaces with radii equal to the range D. However, in this case, uncertainty arises due to the fact that the three spheres have two points of intersection, to eliminate which they use additional ways orientation.

Difference and total rangefinder method is based on determining the difference or sum of ranges from the aircraft to two measuring points. In the first case, the position surface is a two-sheet hyperboloid and to determine the coordinates of the object it is necessary to have one more (leading) station. In the second case, the position surface has the form of an ellipsoid.

Combined method Typically used in radar systems, where the aircraft's position is defined as the point of intersection of a spherical position surface with a radius equal to the range ( D=const), conical surface position ( b=const) and vertical surface position ( a=const).

Doppler method determining the speed and location of an aircraft is based on the effect of changing the frequency of the carrier signal emitted by the transmitter and perceived by the receiving device depending on the speed of their relative movement:

F d =¦ pr -¦ 0,

Where F d- Doppler frequency,

¦ pr - frequency of the received signal,

¦ 0 - frequency of the transmitted signal.

Doppler frequency measurements can be taken unsolicited or request method. At unsolicited method, the radial speed of the aircraft at the signal wavelength l 0, is defined:

V r =F d l 0,

at request method:

V r =F d l 0 /2.

To determine the range, you should integrate the results of measuring the flight speed over the time the object moves from starting point. When calculating coordinates, dependencies for total rangefinder systems are used.

Schemes for determining aircraft parameters based on the Doppler effect are shown in Figure 9.12.

Rice. 9.12. Scheme for determining aircraft coordinates using the Doppler method:

a) without signal relay, b) with signal relay

When carrying out external trajectory measurements of the movement of small aircraft (bullets, artillery and rocket shells), Doppler range radar stations DS 104, DS 204, DS 304 manufactured by NTIIM are used.

Rice. 9.13. Doppler range radar stations

DS 104, DS 204, DS 304

They use the query method and allow you to determine speeds on any part of the trajectory, current coordinates in the vertical plane, calculate accelerations, Mach numbers, drag coefficient, average and median deviations of the initial speed in a group of shots.

Basic specifications DS 304 stations are as follows:

Minimum caliber - 5mm,

Speed ​​range - 50 – 2000 m/s,

Range - 50000 m,

Speed ​​measurement error - 0.1%,

Probing signal frequency - 10.5 GHz,

The level of generated signal power is 400 mW.

Radio navigation methods for determining coordinates, rangefinder method, position lines, rangefinder method error.

Navigation

Orthodromy

Surface position

Position line

Rangefinder method.

This method is based on measuring the distance D between the points of emission and reception of a signal by the time of its propagation between these points.

In radio navigation, rangefinders operate with an active response signal emitted by the transponder transmitter antenna (Fig. 7.2, a) when receiving a request signal.

If the propagation time of the request signals t3 and the response t0 is the same, and the time of formation of the response signal in the transponder is negligible, then the range measured by the interrogator (radio rangefinder) is D = c(t3 + t0)/2. The reflected signal can also be used as a response, which is what is done when measuring the radar range or altitude with a radio altimeter.

Surface position rangefinder system is the surface of a ball with radius D. Position lines There will be circles on a fixed plane or sphere (for example, on the surface of the Earth), which is why rangefinder systems are sometimes called circular. In this case, the location of the object is determined as the point of intersection of two position lines. Since the circles intersect at two points (Fig. 7.2.6), ambiguity of reference arises, to eliminate which additional means of orientation are used, the accuracy of which may be low, but sufficient for a reliable choice of one of the two intersection points. Since the signal delay time can be measured with small errors, rangefinder RNS make it possible to find coordinates with high accuracy. Radio range finding methods began to be used later than goniometric methods. The first samples of radio range finders based on phase measurements of time delay were developed in the USSR under the leadership of L. I. Mandelstam, N. D. Papaleksi and E. Ya. Shchegolev in 1935-1937. The pulse ranging method was used in the pulse radar developed in 1936-1937. under the leadership of Yu. B. Kobzarev.

Radio navigation methods for determining coordinates, goniometer-rangefinder method, position lines, error of the goniometer-rangefinder method.

Navigation- the science of methods and means that ensure the driving of moving objects from one point in space to another along trajectories that are determined by the nature of the task and the conditions for its implementation.

Orthodromy- an arc of a great circle, the plane of which passes through the center of the globe and two given points on its surface.

In radio navigation, when finding the location of an object, the concepts of radio navigation parameter, surfaces and position lines are introduced.

Radio navigation parameter (RPP) is a physical quantity directly measured by the RNS (distance, difference or sum of distances, angle).

Surface position calculate the geometric location of points in space that have the same RNP value.

Position line there is a line of intersection of two position surfaces. The location of an object is determined by the intersection of three position surfaces or a surface and a position line.

The rangefinder method for determining the location and components of the velocity vector of objects using radio signals from spacecraft of satellite radio navigation systems can be used in space radio navigation and geodesy. According to the method, satellite navigation radio signals are received by an N-channel receiving device installed at the object, the distances from the objects to each satellite are determined by measuring the time shifts of the code sequences generated by the satellite generators relative to the code sequence generated by the object generators, as well as the components of the velocity vector by measuring the received Doppler frequency shifts using carrier tracking systems. In this case, in an N-channel receiving device, one of which is the master, and the others are slave channels, the difference in ranges is determined between the ranges measured by the slave receiving devices and the range measured by the master receiver, as well as the differences in the rates of change of ranges are determined between the rates of change ranges calculated from the Doppler frequency shift measurements of the slave receivers and the range rate of change calculated from the Doppler frequency shift measurements of the master receiver, then the double range differences and double range rate differences are determined by mutually subtracting the range differences and the rate of change differences from each other ranges. The technical result consists in increasing the accuracy of determining the location coordinates that make up the velocity vector of the object being determined using the navigation signals of the SRNS spacecraft; and using radio signals from ground-based air sources of radio emissions, as well as using radio emissions from spacecraft of other systems and simulators. 4 salary f-ly, 3 ill.

The invention relates to the field of space radio navigation, geodesy and can be used to determine the location coordinates and components of the velocity vector of objects. There is a known Doppler difference-rangefinder method for determining the location coordinates and components of the velocity vector of objects from navigation radio signals of spacecraft (SC) of satellite radio navigation systems (SRNS), based on measurements of the differences in topocentric distances between an object and two positions of the same navigation spacecraft (SV) in successive moments in time (P.S. Volosov, Yu.S. Dubenko and others. Ship satellite navigation systems. Leningrad: Sudostroenie, 1976). Practical implementation known method are the Russian SRNS "Cicada" and the American SRNS "Transit" - first generation navigation systems. In it, integration of the Doppler frequency shift of radio signals received over a time interval T from a navigation artificial Earth satellite (NES) makes it possible to determine the number of wavelengths that fit into the difference in distances from the phase center of the antenna of the object’s receiving device to two positions of the NES (two positions of the phase center of the NES antenna): where t 1 and t 2 are the time of transmission of NIS time stamps; R 1 (t 1) and R 2 (t 2) - distances between the phase centers of the antennas of the object and the satellite; c is the speed of light; f p - frequency of the received signal; f o - frequency of the reference signal, f p = f and f and +f io +f tr +f gr +f dr, where
f and is the frequency of the signal emitted by the satellite;
f and - instability of the frequency of the emitted signal;
f io, f tr - unknown frequency shifts caused by signal propagation in the ionosphere, troposphere;
f gr - unknown frequency shift due to gravitational forces;
f dr - unknown frequency shifts due to other factors,
f o = f and f+f o ,
Where
f o - known constant frequency shift (frequency bias);
f - instability of the reference signal frequency. Taking into account the above, the expression will take the form

It is clear from the expression that the integral Doppler frequency shift is determined by two terms. The first term is measurement errors caused by the conditions of radio wave propagation, the Earth's gravitational field, instability of the reference oscillator radiation frequency and other factors. They will enter the navigation equation as unknowns. The second term is a direct measurement of the change in slant range in the wavelengths of the reference frequency of the detected object. The addition error of the carrier tracking system (CSR), which is absent in the considered navigation equation, is also included in the measurement error of the radio navigation parameter (RPP). The monitored function of time - the frequency carrier has non-zero high order derivatives. Consequently, in addition to random errors (noise), a real servo circuit with finite order astatism will have dynamic errors caused by the presence of derivatives of the input action of a higher order than the order of the system astatism. Reducing the random error of the phase-locked loop (PLL) of the SSN requires the use of a more inertial loop feedback(narrowing the low-pass filter bandwidth), but at the same time the dynamic errors of the SSR increase and vice versa. Expressing ranges through the coordinates of a rectangular geocentric coordinate system, the navigation equation takes the form
,
Where
x 1, y 1, z 1, x 2, y 2, z 2 - coordinates of the phase center of the satellite antenna at times t 2 and t 1, respectively;
x 0 , y 0 , z 0 are the unknown coordinates of the phase center of the antenna of the object being determined. As you can see, three measurements of range differences in four consecutive positions of the satellite in orbit make it possible to determine the coordinates of the object x 0, y 0, z 0. During the measurement process, it is necessary to wait until the range to the satellite changes by a sufficient amount. The difference-range-measuring method shows its advantages at such distances (bases) between the positions of the satellite in orbit when they are commensurate with the distances between the satellite and the object being determined. In accordance with the above, the disadvantages of the known method are
errors caused by SSR;
errors due to instability of the radiation frequency of the satellite and the reference oscillator;
systematic and random errors;
low accuracy in determining the location coordinates and components of the velocity vector of objects when using satellite satellites in medium-high and high orbits. A rangefinder method is also known, which is adopted as a prototype. The practical implementation of this method is the second generation SRNS - the Russian Global Orbiting Navigation Sattellite System (GLONASS) and the American Global Positioning System (GPS). The geometric equivalent of the final algorithm of this method of solving a navigation problem is the construction of a set of position surfaces relative to the used navigation artificial Earth satellites (NES), the intersection point of which is the desired position of the object (On-board satellite radio navigation devices. /Ed. V.S. Shebshaevich. M. : Transport, 1988). To solve a navigation problem, the minimum required volume of functional dependencies must be equal to the number of estimated parameters. Determining the coordinates of an object’s location comes down to solving a system of equations

Where
R 1, . . . , R 4 - results of slant range measurements obtained using a delay tracking system (DSS);
x, y, z - object coordinates in a geometric rectangular coordinate system;
x 1 , y 1 , z 1 .... x 4 , y 4 , z 4 - coordinates of four travelers transmitted in the navigation message;
R t is the difference between the true range of the satellite object and the measured one, due to the shift in the time scale of the object relative to the time scale of the satellite;
R 1 ,..., R 4 - measurement errors caused by the atmosphere, ionosphere, and other factors. To determine the coordinates of an object's location, it is necessary that four satellites be simultaneously in the object's field of view. As a result of solving this system of equations, four known ones are determined: three coordinates of the object’s location (x, y, z) and the correction Rt to its time scale (correction to the clock). Similarly, using the results of measurements using the SSN, three components of the velocity vector and corrections to the frequency of the object frequency standard used to generate the time scale are determined:
,
Where
- speeds of change of ranges (radial speeds), measured using SSN;
- components of the object’s velocity vector;
- components of the velocity vector of four satellites;
- the difference between the true speed and the measured one, due to the discrepancy between the frequencies of the frequency standards of the satellite and the object;
- measurement errors due to radio wave propagation conditions and other factors. Range measurement in the object's equipment is carried out by measuring the time interval between the time stamps of the code received from the satellite and the local code of the object. The effectiveness of this method is determined mainly by the noise error in RNP measurement, since it is the noise error that limits the effect of compensation for highly correlated errors. To estimate the noise error, the expression is used (On-board satellite radio navigation devices. /Ed. V.S. Shebshaevich. M.: Transport, 1988)

Where
2w - measurement noise dispersion;
- duration of the rangefinder code element;
c/N 0 - ratio of signal power to noise power spectral density at the receiver input;
B CVD - one-way bandwidth CVD;
B IF - one-way bandwidth of the IF discriminator;
K 1 , K 2 are constant parameters depending on the chosen technical solution. The Doppler frequency shift measurement is based on measuring the range increment at the carrier frequency using a CCH. An estimate of the accuracy of measuring the range increment is determined by the expression for the dispersion of phase 2 f of the carrier tracking circuit, which has the form

Where
- carrier wavelength;
B CCH is the bandwidth of the carrier tracking circuit. The noise error in measuring range increments at the carrier frequency is almost an order of magnitude smaller than the noise error in measuring ranges using rangefinder codes. The rangefinding method does not allow, for example, due to differences in GLONASS and GPS SRNS, to use them together. Thus, the disadvantages of the known method, the prototype, are
errors of the tracking system due to the delay from the signal-to-noise ratio;
errors of the carrier tracking system from the signal-to-noise ratio;
errors caused by the conditions of radio wave propagation in the ionosphere, troposphere and other factors;
errors caused by a shift in the time scale of the object relative to the time scales of the satellite due to the instability of the frequencies of the satellite generators and the reference generator of the object;
impossibility of sharing sources of radio emissions from systems for various purposes. To eliminate the ionospheric delay, known methods use hardware compensation using dual-frequency measurements and compensation using corrections calculated from a priori data. The known method (prototype) is characterized by the following set of actions on received satellite radio navigation signals:
reception by an N-channel receiving device of two-frequency radio signals N NIS;
determining the distances from the object to each satellite by measuring the time shifts of the code sequences generated by the satellite generators relative to the code sequence generated by the object generator;
measuring range increments by measuring carrier phase increments;
determination of object location coordinates;
determination of the components of the object's velocity vector. The purpose of the invention is to increase the accuracy of determining the location coordinates, components of the velocity vector of the object being determined using the navigation radio signals of the SRNS spacecraft and using radio signals from ground-based air sources of radio emissions, as well as using radio emissions from spacecraft of other systems and their simulators. The goal is achieved by the fact that according to the proposed method, in an N-channel receiving device, one of which is the master and the others are slave channels, the difference in ranges between the ranges measured by the slave receiving devices and the range measured by the master receiving device is determined, as well as the determination differences in the rates of change of ranges between the rates of change of ranges calculated from measurements of the Doppler frequency shifts of the slave receiving devices, and the rate of change of range calculated from the measurement of the Doppler frequency shift by the master receiver, then the double differences of ranges and double differences of the rates of change of ranges are determined by mutually subtracting each other from each other between differences in ranges and differences in the speed of change of ranges. Additional differences of the proposed method are the following. The host and receiving devices determine the range differences between the object and two satellite positions, determined by the measuring interval by measuring the carrier phase increments using phase-locked frequency tuning systems for tracking the carriers of satellite navigation radio signals. Determination of double range differences is carried out between an object and two satellite positions defined by a measuring interval by measuring the Doppler frequency differences received by receivers using quadrature phase detectors, multiplying their average values ​​by the measuring interval. The master channel receiver receives signals from the satellite signal simulator. Isolation of signals with Doppler frequencies is carried out by squaring the received signals and then returning the frequencies to the desired ones using frequency dividers. The geometric interpretation of the proposed method is illustrated using the example of a constellation of four GLONASS spacecraft and one GPS spacecraft, Fig. 1. The navigation radio signal of the GPS spacecraft received by the receiver is the master signal, and the channel for receiving signals from the GLONASS spacecraft by the receiver is the slave. Accordingly, the navigation signals of the GLONASS spacecraft and the spacecraft receiving device are slaves. In accordance with the above

Where
- the difference in measured ranges between each slave GLONASS spacecraft - user and between the leading GPS spacecraft - user using rangefinder codes;
- double range differences. The geometric interpretation of determining the coordinates and components of the velocity vector from differences in range increments and double differences in increments measured using carrier phase increments is illustrated using the example of two spacecraft: a master spacecraft and one slave GLONASS spacecraft, Fig. 2. Points t 1 , t * , t 2 indicate the positions of the satellite in orbit, which are the boundaries of the navigation parameter readings (dimensional interval). The differences in range increments will be written as follows, respectively:

The double differences in range increments will take the form

The range differences in square brackets of the system of equations (1) show their advantages, as was shown above at such distances (bases) between the positions of the satellite in orbit when they are commensurate with the distance between the satellite and the object being determined. In our example, the bases are insignificant. To satisfy this condition, system of equations (2) is transformed into an identical system of equations for which this condition is satisfied:

Thus, from the system of range differences for satellite orbits with identical orbital parameters for a constellation of 5 satellites, one GPS is the master, four GLONASS are the slaves. The final systems of equations for double differences in ranges (1) and for double differences in range increments (3), expressed through coordinates in a geometric rectangular coordinate system, take the form
for double range differences
,
For double differences in range increments
;
;
,
Where
- coordinates of the slave satellites, transmitted in navigation messages at times t 1, t 2, respectively. Similarly, using the measurement results using the SSN, the components of the velocity vector are determined:
;
;
,
Where
- components of the NIS velocity vector transmitted in navigation messages at times t 1, t 2, respectively. Analyzing the systems of navigation equations of double differences in ranges (4), double differences in increments of ranges (5) and speeds (6) using the master, slave satellite radio signals and the corresponding receiving devices, channels, we see that in the equations the coordinates of the leading satellite GPS are compensated, and also compensated errors caused by discrepancies between the time scales and frequencies of GPS, GLONASS relative to the time scale and frequency of the object. If the navigation equations of the known method contain errors caused by the ionosphere and troposphere, then the equations of the proposed method using double range differences contain their differences. To ensure high accuracy in solving the navigation problem due to the geometric factor of determining the position in space, the position of the spacecraft in space is selected such that one spacecraft is at the zenith (providing high accuracy in determining the vertical position), and the remaining spacecraft are in the horizontal plane in the directions differing from each other by 120 - 180 o (providing high accuracy in determining the horizontal position) depending on the number of spacecraft used. Thus, the proposed method, despite, for example, serious differences in GLONASS and GPS, in the methods of specifying ephemeris, in the layout of superframes and structures of service information frames, in the non-identity of the spatial coordinate reference systems used and the differences in time scales formed from different frequency standards and time, allows their joint use without bringing them into the required compliance, i.e. without any organizational material modifications and modifications to the mathematical support of the systems. By receiving radio navigation signals from GLONASS and GPS spacecraft in parallel or sequentially, using a multiplex or multi-channel receiving device, and also taking GPS spacecraft as the master in one series of measurements, and GLONASS spacecraft as the slave and vice versa in another series, it is possible to determine the coordinates and components of the velocity vector object both in the GPS coordinate-time system and in the GLONASS coordinate-time system, without bringing them into compliance. Sharing the systems will ensure a certain universality of navigation definitions, reliability and reliable observation by comparing the results of definitions for different systems to identify cases of malfunction of one of the systems. The reliability of navigation support refers to the ability of a navigation system to provide an object with information to determine its location at any time with an accuracy guaranteed for the working area. Reliability is understood as the ability of a navigation system to detect deviations in its functioning, leading to a deterioration in the accuracy of determining the coordinates and components of the object’s velocity vector beyond the specified permissible values. If the system of navigation equations of double differences of the proposed method using measurements using rangefinder codes (1) is essentially a system of equations of range differences, then the system of navigation equations of double differences of range increments measured using carrier phase increments on the measurement interval (2) is a system equations of double range differences and also allows you to solve a navigation problem - to determine the location coordinates and components of the object’s velocity vector. Since, as was shown above, the accuracy of measuring double differences in phase increments at carrier frequencies is an order of magnitude higher than the accuracy of measuring differences in time shifts of code sequences, then the accuracy of solving a navigation problem using phase increments is also higher than the accuracy of solving using range differences. In order to further improve the accuracy of solving the navigation problem using phase increments at carrier frequencies by eliminating the error caused by the SCH from measurements, double differences in range increments are produced by isolating from received signals with frequencies equal to Doppler frequency differences using quadrature phase detectors, at the first outputs of which receive the master signal, and the second inputs receive the signals of the slave receiving devices, then the phase increment differences are determined by multiplying the average values ​​of the Doppler frequency differences by the measured interval and determining the double phase increment differences by their mutual subtraction. The above corresponds to the hardware implementation, the block diagram of which is shown in Fig. 3. Isolation of signals with Doppler frequencies when receiving phase-modulated signals with suppressed carriers is carried out by squaring them and filtering them, followed by returning the frequencies to the desired ones using frequency dividers. Signals from the outputs of the convolution devices, which are fed to the PLL systems of the receiving devices in Fig. 3, in the delay synchronization mode, the rangefinder codes are significantly narrowband signals - reconstructed carriers modulated with digital information. The ranges of changes in carrier values ​​are determined mainly by the Doppler shift (50 kHz at GPS, GLONASS spacecraft frequencies), and the signal spectrum width is determined by the spectrum of digital information (100 Hz). PLL signals can track signals corresponding to only one of the two sidebands, and therefore have an energy loss of 3 dB. Therefore, the connection of devices for extracting from the received navigation signals equal to the Doppler frequency differences of the proposed method in Fig. 3, excluding the second sidebands, does not introduce additional energy losses. Received and converted satellite navigation radio signals arriving at quadrature phase detectors already carry frequency shifts due to instabilities of the spacecraft generators, the object, due to the conditions of radio wave propagation (ionosphere, troposphere), shifts due to receiving paths and other factors. Therefore, in the process of isolating oscillations with frequencies equal to the Doppler frequency differences of the proposed method, the listed frequency deviations partially compensate each other. And even with triple differences, their contribution to the accuracy of navigation determinations will be insignificant. When phase increments are used to solve the navigation problem, the influence of phase increments on accuracy due to the ionosphere, the tropospheres for the extreme points of the measurement interval differ little and are practically eliminated when second differences are formed. A special distinctive feature of the proposed method is that when measuring differences in phase increments using oscillations equal to differences in Doppler frequencies, the signal of any radiation source can be used as a leading signal: ground-based, air-based or radiation from spacecraft of other systems. In this case, the main requirement for the receiving device of the detected object is the ability to receive the signal and convert it in such a way that it ensures the operation of the block of quadrature phase detectors. Moreover, the coordinates of radiation sources, their time systems, frequency instabilities and frequency increments due to the propagation of radio waves do not need to be known. They are compensated during navigation measurements. The most optimal option for the hardware implementation of the proposed method is the option when carrier signals modulated by the rangefinder codes of the simulators are used as the leading signal of the object's receiving device. Simulators make it possible to optimize the rate of change of frequencies specifically for each type of navigation systems and thereby ensure their optimal operation in terms of obtaining the potential accuracy of determining the location coordinates and components of the object’s velocity vector. Distinctive features of the proposed method:
reception by an N-channel receiving device of navigation radio signals from N satellites, one of the channels of which is the master, and the others are slaves;
determining range increment differences and range differences by subtracting from the measured carrier phase increments and code sequence time shifts by the slave receiving devices the carrier phase increments and code sequence time shift measured by the master receiving device;
determining double differences in ranges of increments of ranges and ranges by mutual subtraction of differences in double differences in carrier phase increments and differences in time shifts of code sequences in a sequence determined by the geometric factor for determining the position in space;
using differences in double differences in carrier phase increments to determine the coordinates and components of the object’s velocity vector;
measuring double differences in range increments by isolating signals with frequencies equal to the differences in Doppler frequencies received by the master and each slave channels of the receiving device using quadrature phase detectors, the first inputs of which receive signals from the master channel, and the second inputs receive signals from the slaves, and multiplying them average values ​​per measuring interval;
reception by the leading channel of the receiving device of radio signals from ground-based, airborne sources of radio emissions and radio emissions from spacecraft of other systems;
use of simulators by the leading channels of the receiving device as a signal;
isolating signals with Doppler frequencies when receiving phase-modeled signals with suppressed carriers by squaring them and filtering them, followed by returning the frequencies to the desired ones using frequency dividers. Thus, the proposed method for determining the location coordinates and components of the velocity vector of objects from the radio signals of the SRNS spacecraft has novelty, significant differences and, when used, gives a positive effect consisting in increasing the accuracy, reliability and reliability of navigation determinations of satellite and ground-based radio navigation systems.