RU2800227C1 - Air object ranging system - Google Patents

Abstract

FIELD: radar devices.

SUBSTANCE: invention can be used to accurately determine the distance from a radar station to an air object (AO). An unmanned aerial vehicle (UAV) is introduced into the ranging system with an active response to probing interrogation signals, the frequency of which differs from the main frequency of the radiation of the radar station. UAVs are proposed to be located in the area of the alleged appearance of the AO. It is proposed to control the position of the UAV using code control signals emitted by the ranging system. To receive signals about the coordinates of the location of the UAV, it is proposed to use the radiation of response signals from the UAV with information received by the onboard GPS system of the UAV. It is proposed to supplement the design of the known ranging system with the first and second antenna switches, two antennas, a UAV control unit, a UAV signal receiver, a UAV request signal transmitter and a second range converter.

EFFECT: providing in the system for measuring the distance to an air object the ability to compensate for inaccuracies in measuring the distance to an air object associated with the phenomenon of refraction.

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Description

The invention relates to radar devices and can be used to accurately determine the distance from a radar station to an air object.

A device for determining the range [1] is known, in which the synchronizer outputs a synchronization signal to the transmitter, allowing the radiation of a radio pulse into space, and also to the range converter to carry out the reference range. The signal reflected from the air object enters the receiving device, which converts electromagnetic energy into an electrical signal, which enters the range converter, which determines the time mismatch between the synchronizer pulse and the signal of the receiving device. The measured time mismatch according to known dependencies is converted into information about the range. The distance to the object is displayed on the indicator. The range accuracy in this device is not always sufficient. Devices similar to the above are presented in [2].

A system (device) for measuring the range of an air object [3] is known, containing a transmitting device, the input of which is connected to the output of the synchronizer and the first input of the range converter (TD), the second input of which is connected to the output of the receiving device, and the output is connected to the first input of the first subtractor and the input of the sensor for measuring the distance to the reference object, the output of which is connected to the second input of the second subtractor and the input of a permanent storage device, the output of which is connected to the first input of the second subtractor, the output of which is connected to the second input of the first subtractor, connected by its output to the input of the indicator.

This device allows you to measure the distance to the location object (air object) and refine it by reflected signals from the reference object (EO), which can be a local object (building, island in the ocean, power line tower, etc.). Due to the correction of the measurement, calculated between the current reflections from the EO and previously made accurate reliable measurements of the distance to the EO, the errors in determining the range associated with the refraction of radio waves and other negative factors in estimating the time delays of the radar signal are eliminated. However, the efficiency of this device cannot be considered high due to the following circumstances. First, there may be no EO in the direction of the object of interest. Secondly, local objects used as EO, as a rule, have a low height and can be used to clarify the range of only low-flying airborne objects (LO). Thirdly, the direction-finding AO can have a range close to the range of the EO existing in a given angular direction, which does not make it possible to distinguish between the signal reflected by an air object and the signal scattered by the EO, which leads to a methodological error in updating the range.

The objective of the invention is to improve the system for measuring the range to an air object, namely, to give it the ability to compensate for inaccuracies in measuring the range to an air object associated with the phenomenon of refraction, under any location conditions, including in the absence of reference reflectors in the direction of the direction-finding air object.

The solution to the problem of the invention is proposed to be built on the basis of the use of a specialized unmanned aerial vehicle (UAV) with an active response to probing interrogation signals, the frequency of which differs from the main frequency of the radiation of the radar station, on the basis of which the ranging system is implemented. A specialized unmanned aerial vehicle (UAV) is proposed to be located in the area of the alleged appearance of the VO. And it is proposed to control the position of the UAV with the help of coded control signals emitted by the ranging system (LED). For reliable reception of signals about the coordinates of the location of the UAV, it is proposed to use the emission of response signals from the UAV board with information received by the onboard GPS system of the UAV. This will allow taking into account the AO range measurement error associated with the refraction of radio waves from any direction, at any height in the UAV flight altitude range, in the absence of reflectors of natural or industrial origin.

To solve the problem of the invention, the design of the known AO ranging system [1] is proposed to be supplemented with the first and second antenna switches (AP), two antennas, a UAV control unit, a UAV signal receiver (PUSSBLA), a specialized UAV request signal transmitter (PSZSBLA), a second range converter (RD), as well as a specialized UAV. In this case, the input-output of the first antenna is proposed to be connected to the input-output of the first AP, the input of which is to be connected to the output of the transmitting device. The second input of PSZSBLA is proposed to be connected to the output of the synchronizer and the first input of the second PD, the output of which is to be connected to the second input of the second subtractor, and the second input to the second output of the PUSSBL, the input of which is to be connected to the output of the second AP. The first output of the UAV control unit is proposed to be connected to the first input of the PSZSBLA, and the second output - to the third input of the first subtractor, the first input of which is connected to the second input of the UAV control unit, the first input of which is connected to the first output of the PUSSBL and the first input of the second subtractor, and the mechanical input to the mechanical output of the first antenna. The output of the first AP is proposed to be connected with the input of the receiving device, the input of the second AP is connected to the output of the PSZSBLA, and the input-output of the second AP is connected to the input-output of the second antenna.

Structural diagram of the air object ranging system is shown in the drawing. The scheme includes the first antenna 1, the UAV control unit (BUSBLA) 2, the PUSBLA 3, the first AP 4, the receiving device 5, the transmitting device 6, the first PD 7, the UA request signal transmitter 8, the synchronizer 9, the second PD 10, the first subtractor 11, the second subtractor 12, the indicator 13, the SUVLA 14, the second antenna 15 and the second AP 16.

At the same time, the input-output of the first antenna 1 is connected to the input-output of the first AP 4, the output of which is connected to the input of the receiving device 5. The first output of the PUSBLA 3 is connected to the first input of the second subtractor 12 and the first input of the control unit of the SULA 2, the mechanical input of which is connected by its drive to the mechanical output of the first antenna 1. The first output of the control unit of the SULA 2 is connected to the first input of the PSZSBLA 8, the output of which is connected to the input of the second AP 16, the output of which is connected to the input of PUSSBLA 3, the second output of which is connected to the second input of the second PD 10, the output of which is connected to the second input of the second subtractor 12. The output of the synchronizer 9 is connected to the first input of the first PD 7, the input of the transmitting device 6, the second input of the PSZSBLA 8 and the first input of the second PD 10. The output of the receiving device 5 is connected to the second input of the first PD 7, the output of which is connected to the first input of the first reader 11 and the second input of BUSBLA 2, the second output of which is connected to the third input of the first subtractor 11, the output of which is connected to the input of the indicator 13, and the second input is connected to the output of the second subtractor 12. The output of the transmitter 6 is connected to the input of the first AP 4, and the input-output of the second antenna 15 is connected to the input-output of the second AP 16.

The system for measuring the range of an air object operates as follows. The synchronizer 9 generates clock pulses that are fed to the input of the transmitter 6, the first inputs of the first PD 7, the second PD 10, as well as to the second input of the PSSBL 8. The clock signals enable the launch and synchronization of the operation of the transmitters 6 and 8, using the signals of the corresponding different frequencies (f1 and f2). The time separation between the emitted signals of the transmitter 6 at a frequency fl and the signals of the PSSBL 8 at a frequency f1 is provided by a delay implemented in block 8 using the built-in delay line. Synchronizer signals 9 at the first inputs of the range converters 7 and 10 determine the delay time between the emitted and received signals. An example of using a range converter is presented in [4]. In the absence of the possibility of separating the signals of transmitters 6 and 8 in time, it is possible to alternately probing them with space signals, in which signals at a frequency f1 are used in even repetition periods, and signals at a frequency f1 are used in odd repetition periods.

The transmitter 6 generates a radiated microwave signal at a frequency f1 of the order of 10 ⁹ -10 ¹⁰ Hz and feeds it to the input of the first AP 4, which closes the receiving channel for the duration of the powerful radiated signal. After passing the first AP 4, the probing microwave pulse comes from the input-output of the first AP 4 to the input-output of the first antenna 1 and is radiated by it in the direction of the air object. The reflected VO signals can be received by the first antenna 1 only when the VO is in the beam of the directional characteristic of the antenna 1, that is, when the aperture of the antenna 1 is directed towards the VO. The antenna drive 1 is mechanically (by a gear-shaft transmission) connected to the input drive of the BUSBLA 2. Thus, the angular coordinates of the elevation angle ε _in and azimuth β _in the air object, associated with the angular position of the input drive of the BUSBLAH 2, are transmitted to the BUSBLAH by means of a mechanical connection of the input drive of the block 2 with the antenna drive 1.

The control circuit of the angular position of the first antenna 1 and the second antenna 15 is not shown in the drawing. It is assumed that they provide constant tracking by the first antenna 1 of the direction to the VO, and the second antenna 15 - the direction to the UAV 14. The order of tracking the VO in angular coordinates is known [5-7] and does not affect the essence of the proposed invention. Tracking the angular position of the UAV by the second antenna occurs according to the coordinates of the UAV known to the angular automation system (antenna control system), which are received in the LED in the form of messages from the UAV 14.

The reflected VO signals are received by the first antenna 1 and from its input-output are fed to the input-output of the first AP 4, after passing which they enter the input of the receiving device 5. The input filter of the block 5 does not pass signals at the frequency f2 to the receiver 5, which is used by the UAV request channel 14 and the UAV response signal processing channel. The receiving device 5, the input filter of which is tuned to the frequency f1, amplifies the received reflected signals and transmits them from its output to the second input of the first range converter 7. The purpose of block 7 is to determine the time mismatch between the pulses of the synchronizer 9 and the received reflected VO signals in each probing period. The time mismatch is associated with the well-known analytical dependence [5-7] with the distance to the AO. An example of using a range converter is presented in [4].

A signal proportional to the distance to VO D _in from the output of the first PD 7 is fed to the first input of the first subtractor 11. In the subtractors 11 and 12, the difference between the values of the ranges received at their different inputs is determined. An example of using a subtractor is given in [8]. Due to the presence of the refraction effect [9], the distance to the AO, extracted from the reflected signals by block 7, may not be accurate enough. To refine it, a correction signal ΔD _bla is used, which is fed to the second input of the first subtractor 11 from the output of the second subtractor 12. To obtain the correction signal ΔD _bla, UAV signals 14 are used.

The second antenna 15 during the operation of the LED constantly monitors the position of the UAV 14 according to the coordinates of the location of the UAV, which in the form of code sequences in the response signals of the UAV 14 enter the LED through the second antenna 15. In other words, the specialized UAV 14 periodically emits in the direction of the aperture of the second antenna 15 LED code signals at a frequency f2, which contain information about its own Cartesian coordinates X _bla ,Y _bla , Z _UAV obtained with the onboard GPS receiver UAV 14 [10, 11]. These signals are received by the second antenna 15 and are fed from its input-output to the input-output of the second AP 16, and then from its output to the input of PUSSBL 3. In block 3, the signals emitted by the onboard antenna of the UAV 14 are amplified, decoded, and information about the coordinates of the UAV 14 is extracted from them X _bla ,Y _bla ,Z _bla . This information is transmitted from the first output of PUSBLA 3 to the first input of BUSBLA 2. Since the Cartesian coordinates X ₀ ,Y ₀ , Z ₀ of the first LED antenna are known, based on the knowledge of the coordinates of the first LED antenna and the coordinates of the UAV X _bla ,Y _bla ,Z _bla in block 3 according to known dependencies [12-14], an accurate calculation of the slant range to the UAVS D _bla+ is carried out, the value of which is c the first output of PUSBLA 3 is fed to the first input of BUSBLA 2 and the first input of the second subtractor 12.

The selection by block 2 and block 12 of the signals required by their purpose can be provided by time gating, the amplitude value of the corresponding signal, the polarity of the signals with the necessary information, etc. Separate outputs of unit 3 can also be provided for range signals D _bla+ and coordinates X _bla ,Y _bla ,Z _bla .

The second antenna 15 periodically emits at a frequency f2 in the direction of the UAV 14 a special request signal U _to measure the distance to the UAV in terms of the delay time of the retransmitted (simulating reflected) signal, as well as code sequences with information about the coordinates of the VO, and more precisely about the magnitude of the discrepancies between the Cartesian coordinates of the UAV 14 and VO ΔX, ΔY, ΔZ. Signal U _to has a special duration or a special code mark that allows you to distinguish it from other information signals. The signal U _k received by the UAV 14 onboard equipment is amplified and retransmitted without delay in the direction of the second antenna 15. If there is a small delay Δτ between the received signal U _k and the signal U _cr relayed by the UAV, the time delay Δτ is always a priori known, and therefore can be taken into account when measuring the distance to the UAV by the delay time.

Принятый второй антенной 15 переизлученный (ретранслированный) сигнал U _кр с ее вход-выхода поступает на вход-выход второго АП 16 и далее с его выхода - на вход ПУССБЛА 3, где усиливается, проходит согласованную обработку и с второго выхода блока 3 поступает на второй вход второго преобразователя дальности 10. Путем определения временного рассогласования между синхроимпульсом (поступающим на первый вход) и ретранслированным сигналом U _кр (поступающим на второй вход) ПД 10 определяет наклонную дальность D _бла - ДО СБЛА 14, искаженную эффектом рефракции, и подает соответствующий этой дальности сигнал со своего выхода на второй вход второго вычитателя 12. На выходе блока 12 формируется сигнал, выражающий собой разность между значениями дальностей до СБЛА, полученными точным расчетом D _бла+ (на первом входе блока 12) и путем стандартной обработки D _бла- в ПУССБЛА 3 ретранслированного сигнала U _кр (на втором входе). From the output of block 12, the signal of the range difference ΔD _{of the UAV} is fed to the second input of the first subtractor 11.

The signal of the range difference ΔD _bla , arriving at the second input of the subtractor 11, is used by it to clarify the value of the distance IN _D in received at the first input from the output of the first PD 7.

As already noted, in the time intervals set by the signal reception mode, the UAV 14 periodically emits code signal constellations in the direction of the second antenna 15, which contain information about the location coordinates of the UAV X _bla ,Y _bla ,Z _bla . Эти сигналы, пройдя вторую антенну 15 и второй АП 16, поступают на вход ПУССБЛА 3, где дешифрируются и в виде значений координат Х _бла ,Y _бла ,Z _бла с первого выхода блока 3 поступают на первый вход БУСБЛА 2. Угловые координаты ВО ε _во , β _во определяются в блоке 2 по положению механического входного привода, а величина измеренной до ВО дальности D _во поступает в БУСБЛА 2 (на второй вход) с выхода первого ПД 7. Сферические координаты ВО (ε _во , β _во , D _во ) по известным выражениям [12, 14] пересчитываются в декартовы координаты ВО (X _во ,Y _во , Z _во ), что позволяет сравнить в блоке 2 декартовы координаты ВО и СБЛА 14, а затем выработать сигналы несоответствия ΔX,ΔY,ΔZ положений ВО и СБЛА 14. Эти сигналы несоответствия с первого выхода БУСБЛА 2 поступают на первый вход ПСЗСБЛА 8 и после соответствующего усиления через второй АП 16 на частоте f2 излучаются второй антенной 15 в направлении СБЛА 14. Синхроимпульсы, поступающие на второй вход ПСЗСБЛА 8 (они же поступают на вход передающего устройства 6), определяют величину периода повторения сигналов запроса СБЛА 14 и зондирующих сигналов блока 6, а также обеспечивают синхронизацию каналов обработки на частотах f1 и f2. The signals ΔX, ΔY, ΔZ received by the onboard equipment of the UAV 14 are used by it to move to the area where the VO is located, ensuring the adequacy of the effect of refraction on measuring the range to the UAV and VO. In addition, the discrepancy signals ΔX,ΔY,ΔZ in BUSBLA 2 are compared with the threshold values of approach X _p ,Y _p ,Z _p , and under the conditions ΔX<X _p , ΔY<Y _p , ΔZ<Z _n in BUSBLA 2, a signal is generated that allows the clarification of the measured range, which from the second output of BUSBLA 2 is fed to the third input of the first subtractor 11 , allowing him to issue from his output the value of the measured range to the indicator 13 or display on the indicator next to the mark from the VO a special form with the value of the measured range.

Thus, the use of a specialized UAV located in the vicinity of the AO (the degree of proximity is determined by the threshold values of approach X _p , Y _p , Z _p ), allows you to take into account and neutralize the negative effect of refraction on the signal reflected from the AO.

The transmitter 8 can be built according to a typical scheme similar to the transmitter 6 of the prototype. The UAV signal receiver 3 and the UAV control unit 2 must include analog-to-digital converters, processors for performing calculations, as well as digital-to-analog converters and controlled delay lines for generating output signals of the required polarity and located in the required time intervals. Such construction of blocks 2 and 3 is realizable [6, 15] at the present level of technology development. Equipping UAVs with a flight control system and an onboard radar station with the ability to actively respond to a request is also known [16-20]. Thus, the possibility of implementing the proposed invention is obvious.

The proposed system for measuring the range of an air object can be recommended for implementation in radar stations and bearing systems for air objects, where high accuracy in measuring coordinates, including slant range, is required.

Information sources

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Claims (1)

A system for measuring the range of an air object, containing a receiving device connected by its output to the second input of the first range converter, the first input of which is connected to the input of the transmitting device and the output of the synchronizer, and the output is connected to the first input of the first subtractor, the output of which is connected to the input of the indicator, and the second input is connected to the output of the second subtractor, characterized in that it additionally includes a specialized unmanned aerial vehicle emitting code signals in the direction of the second antenna, which contain information about its own Cartesian coordinates, as well as additionally introducing the first and second antennas, the first and second antenna switches, a control unit of a specialized unmanned aerial vehicle, a signal receiver of a specialized unmanned aerial vehicle, a transmitter of request signals of a specialized unmanned aerial vehicle, a second range converter, while the input-output of the first antenna is connected to the input-output of the first antenna switch, the output of which is connected to the input of the receiving device, and the input to the output of the transmitting device, mechanically th output of the first antenna is connected to the mechanical input of the control unit of the specialized unmanned aerial vehicle, the second input of which is connected to the output of the first range converter, and the second output to the third input of the first subtractor, the first output of the control unit of the specialized unmanned aerial vehicle is connected to the first input of the request signal transmitter of the specialized unmanned aerial vehicle, the second input of which is connected to the output of the synchronizer and the first input of the second range converter, the output of which is connected to the second input of the second reader, and the second input - to the second output of the signal receiving device of the specialized unmanned aerial vehicle, the input of which is connected to the output of the second antenna switch, the input-output of which is connected to the input-output of the second antenna, and the input - to the output of the transmitter of the request signals of the specialized unmanned aerial vehicle, the first output of the signal receiver of the specialized unmanned aerial vehicle is connected to the first input of the control unit of the specialized unmanned aerial vehicle and the first input of the second subtractor.

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