CN103116158A - Pulse passive bistatic radar target locating method - Google Patents

Abstract

The invention discloses a pulse passive bistatic radar target locating method and relates to the technical field of passive radar. The method is a method which provides a conventional pulse radar using circumference mechanical scanning as a non-cooperative irradiation source to carry out target locating for a onboard, a ship-bone and a submarine and other mobile platform The conventional pulse radar using the circumference mechanical scanning is used as the non-cooperative irradiation source, a movable receiving station adopts two universal antenna and two simple-structure receiving channels for processing direct waves and target scattered signals from a non-cooperative launch station, base line distance from the launch station to the receiving station, a target azimuth angle of the launch station and bistatic distance are calculated in real time, distance from the target to the receiving station and a target azimuth angle of the receiving station are solved thorough geometrical relationship of the bistatic station, and therefore the position relative to a receiver is confirmed. According to the pulse passive bistatic radar target locating method, a relative cheap receiving system is used for receiving radiating signals of enemy radar to achieve monitoring of a battle field area of enemy and an enemy scout surveillance system can not discover.

Description

A kind of pulse passive bistatic radar object localization method

One, technical field

The invention belongs to the passive radar technical field, relate in particular to a kind ofly under the receiving platform motion conditions, utilize the conventional pulsed radar of circumference mechanical scanning to carry out Technology for Target Location as non-cooperation irradiation source.

Two, background technology

As everyone knows, also can expose existence and the position of transmitter in the process of radar emission electromagnetic wave detection target simultaneously.This will threaten flat pad under hostile environment, even can worsen nervous international relations.And the emission of bistatic radar, receiving trap separate, and the receiver platform can keep mourning in silence.Bistatic radar is divided into cooperative and non-cooperative, but not the cooperative bistatic radar is divided into again based on the non-cooperation bistatic radar of the illuminators of opportunities such as broadcasting, TV or satellite with based on one's own side's non-cooperation bistatic radar of enemy radar radiation source even, also referred to as passive bistatic radar according to the difference of radiation source.

At present, the research of passive bistatic radar Detection Techniques mainly concentrates on the civilian illuminators of opportunity of continuous wave system, and especially the passive bistatic radar detection based on TV or frequency modulation broadcasting has obtained significant achievement, has caused widely to pay close attention to.Yet this type systematic still comes with some shortcomings: 1) for the mobile platform such as airborne, carrier-borne or latent year, due to the mobile platform limited size, can't load the antenna of the television broadcasting signal frequency range that need to reach certain gain; 2) survey for naval target, especially in the off-lying sea, the civil signal resource is very limited, almost can not receive television broadcasting signal in the marine site away from seashore hundreds of kilometer; 3) because the signals such as FM/TV or GPS are not custom-designed for target detection, its signal power (operating distance) and signal bandwidth (range resolution) are often not as radar signal.

Therefore, in the urgent need to exploring a kind of new radar detection system, seek more available signal and radiation source type, make system have more flexible to optional signal, pulsed radar signal this moment (comprising road, sea, sky, space based radar signal) is as non-cooperation radiation source, and the value that consists of bistatic radar with home reception system highlights.Especially the conventional pulsed radar of circumference mechanical scanning, the scan mode of this type of irradiation source is simple, regular, than being more suitable for as non-cooperation irradiation source, for the mobile reception platform situation such as airborne, carrier-borne or latent year, can greatly simplify receiving system complexity, reduce the difficulty of target localization.

Three, summary of the invention

1. the technical matters that will solve

Technical matters to be solved by this invention is: mobile platform provided a kind of conventional pulsed radar of circumference mechanical scanning that utilizes to carry out the method for target localization as non-cooperation irradiation source for airborne, carrier-borne or latent year etc., and it can obtain the two-dimensional coordinate of target.

2. technical scheme

For solving the problems of the technologies described above, the present invention adopts following technical measures:

A kind of pulse passive bistatic radar object localization method is provided, utilize the conventional pulsed radar of circumference mechanical scanning as non-cooperation irradiation source, for the mobile reception platform situation such as airborne, carrier-borne or latent year, receiving station adopts two omnidirectional antennas and two receiving cables simple in structure to process direct wave and target scattering signal from non-cooperation cell site, calculate in real time the cell site to parallax range, cell site's azimuth of target, the bistatic range difference of receiving station, and determine that by bistatic geometric relationship target is with respect to the position of receiver.

Wherein, for the mobile reception platform situation such as airborne, carrier-borne or latent year, the cell site is real-time change to the parallax range of receiving station, this moment, the cell site was by utilizing at a distance of being two omnidirectional antennas of d, by the time interval Δ T of inswept two antennas of measuring radiation source main beam to the parallax range L of receiving station ₁=T _{Antenna 2}-T _{Antenna 1}, one week of radiation source circumference mechanical scanning T.T. T and radiation source incoming signal azimuth angle theta calculate.

Wherein, cell site's azimuth of target θ _TThe time interval Δ T by the measuring radiation inswept receiver of source main beam and target ₂=T _Target-T _ReceiverCalculate with the T.T. T in one week of radiation source circumference mechanical scanning.

Wherein, bistatic range difference R _DBy measuring the time difference Δ t=t of direct wave and target scattering echo _Target-t _{Direct wave}Calculate.

Utilize the parallax range L, the azimuth of target θ of cell site that have calculated _T, bistatic range difference R _D, the bistatic triangle geometric relationship by cell site, target and receiving station consist of just can calculate the range-to-go R of receiving station _R, the azimuth of target θ of receiving station _RThereby, determine that target is with respect to the position of receiver.

3. beneficial effect

The invention has the beneficial effects as follows: only need to use relatively inexpensive receiving system, just can be the enemy radar of nearby working as unconscious non-cooperation radiation source, as long as enemy radar start, system just can work, complete the location to target, thereby realize the supervision to zone, enemy battlefield, and not by enemy's reconnaissance system such as ESM system discovery.This radar has the advantages such as with low cost, that viability is strong, will play a significant role in the future battlefield.

Four, description of drawings

Fig. 1 is enforcement principle schematic of the present invention.

Fig. 2 is parallax range computing method schematic diagram.

Fig. 3 is cell site's azimuth of target computing method schematic diagram.

Fig. 4 is bistatic range difference computing method schematic diagram.

Five, embodiment

Below in conjunction with Figure of description, the present invention is described in further detail.

as shown in Figure 1, the invention provides a kind of pulse passive bistatic radar object localization method, utilize the conventional pulsed radar of circumference mechanical scanning as non-cooperation irradiation source, for airborne, the mobile reception platform situation such as carrier-borne or latent year, receiving station adopts two omnidirectional antennas and two receiving cables simple in structure to process direct wave and target scattering signal from non-cooperation cell site, calculate in real time the cell site to the parallax range of receiving station, cell site's azimuth of target, bistatic range difference, and solve target to the distance of receiving station by bistatic geometric relationship, receiving station's azimuth of target, thereby determine that target is with respect to the position of receiver.

The parallax range computing method as shown in Figure 2, when radiation source adopted mechanical circular scan mode, receiver can adopt at a distance of being two omnidirectional antennas of d, by the time interval Δ T of inswept two antennas of measuring radiation source main beam ₁=T _{Antenna 2}-T _{Antenna 1}, radiation source antenna scanning speed omega and radiation source incoming signal azimuth angle theta are determined distance L, computing formula is as follows:

L＝dcosθ/(ωΔT ₁) (1)

In formula (1), two antenna distance d are known; Radiation source incoming signal azimuth angle theta can utilize the phase method angle measuring principle to record, and namely utilizes the phase differential of two antenna received signals to carry out angle measurement; The time interval Δ T of the radiation source main beam is inswept two antennas ₁Can be by the time interval T between the amplitude peak-peak of two antennas of the inswept receiving station in measuring radiation source _{Antenna 2}-T _{Antenna 1}Record; The corresponding time interval of adjacent peak-peak by same antenna of the inswept receiving station in measuring radiation source can record the scan period T of antenna, thereby can calculate radiation source antenna scanning speed omega=2 π/T.Formula this moment (1) can be write as:

L＝dcosθ/(2πΔT ₁/T) (2)

Cell site's azimuth of target computing method as shown in Figure 3, the transmitter azimuth of target can scan by track transmitter to be determined.As transmitter T _XInswept receiver R _XThe time, at T _ReceiverConstantly, receiver R _XCan receive a peak pulse; As transmitter T _XInswept target T _gAfter, the reflection wave of target is at T _TargetConstantly received machine receives.When radiation source during with constant speed circular scan, the azimuth of target θ of cell site _TDetermine can be by the time interval Δ T between the inswept receiver in measuring radiation source and target ₂=T _Target-T _ReceiverRealize with the T.T. T of radiation source run-down.With sweep spacing Δ T ₂Divided by scan period T, and then multiply by 2 π and just can calculate θ _T, computing formula is as follows:

θ _T＝2πΔT ₂/T (3)

Bistatic range difference computing method as shown in Figure 4, generally, target and receiving station generally are not launched the machine antenna main lobe and cover simultaneously, direct wave is often from the side lobe radiation of radiation source.In figure, base length is L, and the target scattering path again to receiver, longly is R from the transmitter to the target _T+ R _R, bistatic range difference R _D=R _T+ R _R-L.Transponder pulse is t along the time of direct wave propagated _{Direct wave}, be t along the time of target scattering propagated _TargetBistatic range difference R _DCan be by measuring the time difference Δ t=t of direct wave and target scattering echo _Target-t _{Direct wave}, then multiply by light velocity c and calculate, computing formula is as follows:

R _D＝cΔt (4)

By parallax range L, the azimuth of target θ of cell site _T, bistatic range difference R _D, the bistatic triangle geometric relationship by cell site, target and receiving station consist of can get following relational expression:

R _R ²＝R _T ²+L ²-2R _TLcosθ _T (5)

In formula (5), the range-to-go R of cell site _T=R _D+ L-R _R, can calculate the range-to-go R of receiving station _R, computing formula is as follows:

$R_R=\frac{{(R_D+L)}^2+L^2-2L(R_D+L)\cos {\mathrm{\θ}}_T}{2(R_D+L-L\cos {\mathrm{\θ}}_T)}---\left(6\right)$

By parallax range L, the azimuth of target θ of cell site _T, bistatic range difference R _D, the bistatic triangle geometric relationship by cell site, target and receiving station consist of can get following relational expression:

$\frac{R_T}{\sin {\mathrm{\θ}}_R}=\frac{R_R}{\sin {\mathrm{\θ}}_T}---\left(7\right)$

In formula (7), the range-to-go R of cell site _T=R _D+ L-R _R, the range-to-go R of receiving station _RDetermined by formula (6), can calculate the azimuth of target θ of receiving station _R, computing formula is as follows:

${\mathrm{\θ}}_R=\frac{R_D(R_D+2L)\sin {\mathrm{\θ}}_T}{{(R_D+L)}^2+L^2-2L(R_D+L)\cos {\mathrm{\θ}}_T}---\left(8\right)$

Above-mentioned formula is take bistatic geometrical plane model as prerequisite, and under this Model Condition, non-cooperation Radar emitter, target and receiving station are positioned at same plane.Even the consideration target is aerial target, because the horizontal range between non-cooperation Radar emitter and receiving station (being parallax range) is usually far away, the error that this moment, object height caused is less, and therefore this bistatic areal model stands good.

Claims (3)

1. pulse passive bistatic radar object localization method, it is characterized in that: utilize the conventional pulsed radar of circumference mechanical scanning as non-cooperation irradiation source, for the mobile reception platform situation such as airborne, carrier-borne or latent year, receiving station adopts two omnidirectional antennas and two receiving cables simple in structure to process direct wave and target scattering signal from non-cooperation cell site, calculate in real time the cell site to parallax range, cell site's azimuth of target, the bistatic range difference of receiving station, and determine that by bistatic geometric relationship target is with respect to the position of receiver.

2. a kind of pulse passive bistatic radar object localization method as claimed in claim 1, the computing method that it is characterized in that described parallax range, cell site's azimuth of target, bistatic range difference are: adopt at a distance of being two omnidirectional antennas of d, by the time interval Δ T of inswept two antennas of measuring radiation source main beam ₁=T _{Antenna 2}-T _{Antenna 1}, one week of radiation source circumference mechanical scanning T.T. T and radiation source incoming signal azimuth angle theta calculate parallax range L; Time interval Δ T by the measuring radiation inswept receiver of source main beam and target ₂=T _Target-T _ReceiverCalculate the azimuth of target θ of cell site with the T.T. T in one week of radiation source circumference mechanical scanning _TBy measuring the time difference Δ t=t of direct wave and target scattering echo _Target-t _{Direct wave}, then multiply by light velocity c and calculate bistatic range difference R _D

The calculating of parallax range L is based on following formula:

L＝dcosθ/(2πΔT ₁/T)

The azimuth of target θ of cell site _TCalculating based on following formula:

θ _T＝2πΔT ₂/T

Bistatic range difference R _DCalculating based on following formula:

R _D＝cΔt 。

3. a kind of pulse passive bistatic radar object localization method as claimed in claim 1, is characterized in that described target with respect to the computing method of the position of receiver is: utilize the parallax range L, the azimuth of target θ of cell site that have calculated _T, bistatic range difference R _D, the bistatic triangle geometric relationship by cell site, target and receiving station consist of calculates the range-to-go R of receiving station _R, the azimuth of target θ of receiving station _R

The range-to-go R of receiving station _RCalculating based on following formula:

The azimuth of target θ of receiving station _RCalculating based on following formula:

。

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