CN106950550B - High dynamic deviation on-line estimation method based on cross-fuzzy interval judgment under condition of range finding and speed measuring ambiguity - Google Patents
High dynamic deviation on-line estimation method based on cross-fuzzy interval judgment under condition of range finding and speed measuring ambiguity Download PDFInfo
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- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
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Abstract
The invention belongs to the field of radar signal and data processing, and provides a cross-fuzzy interval decision-based high dynamic deviation on-line estimation method aiming at the problem of high dynamic deviation real-time estimation under the condition of range finding and speed measurement. In the research on the problem, firstly, target radial velocity estimation at different moments is obtained by using a distance difference method; secondly, carrying out mutation judgment on the radial speed of adjacent moments, finding out the estimation of the radial speed across the fuzzy interval, and compensating the estimation; then, carrying out median filtering processing on the compensated multiple radial velocity estimates to obtain velocity ambiguity resolution measurement; and finally, carrying out online estimation on the high-dynamic distance delay deviation by using the speed ambiguity resolution measurement. The method can effectively solve the problem of high dynamic deviation estimation under the condition of range finding and speed measuring blur, and has a good effect when the target motion crosses the blur interval.
Description
Technical Field
The invention relates to the field of radar signal and data processing, and aims to solve the problem of high dynamic deviation real-time estimation under the condition of range finding and speed measuring ambiguity.
Background
In the research of early warning and detection of hypersonic speed targets in the adjacent space, LFM signals are widely selected by the current radar system due to the advantage of large time-bandwidth product. However, in the research of using LFM signals to early-warning and detecting an object in the near space, there is a certain dynamic deviation in radar measurement due to the distance-velocity coupling. The deviation may not be considered when the target radial velocity is small, but when the target has a large radial velocity, the radar detection and tracking performance of the target may be seriously affected. For this reason, how to realize the estimation of the high dynamic bias is a key problem which needs to be solved urgently at present.
In the research on high dynamic deviation estimation, the existing documents are mostly established under the assumption that radar measurement is not ambiguous, and the problems of ranging and speed measurement ambiguity in the detection of a high supersonic speed target in an adjacent space are not fully considered. On one hand, under the condition of radar ranging ambiguity, the return moments of different echoes cannot be effectively identified, and further the radar cannot lock the specific position information of the target; on the other hand, under the condition of radar speed measurement ambiguity, the speed measurement is confused due to the frequency spectrum overlapping phenomenon, and further the effective speed information of the target cannot be obtained. Particularly, under the condition that the target moves across the fuzzy interval, the composite influence of radar ranging and speed measurement fuzzy has important influence on the estimation and compensation of high dynamic deviation. However, studies on this aspect have not been found in the prior art.
Therefore, the invention provides an online high-dynamic deviation estimation method under the condition of range finding and speed measurement, which aims to mainly solve the difficult problem of high-dynamic deviation estimation when target motion crosses a fuzzy interval.
Disclosure of Invention
Aiming at the difficult problem of high dynamic deviation estimation under the condition of range finding and speed measurement ambiguity, the method for estimating the high dynamic deviation on line based on the cross-ambiguity interval judgment is provided. Firstly, obtaining target radial velocity estimation at different moments by using a distance difference method; secondly, carrying out mutation judgment on the radial speed of adjacent moments, finding out the estimation of the radial speed across the fuzzy interval, and compensating the estimation; then, carrying out median filtering processing on the compensated multiple radial velocity estimates to obtain velocity ambiguity resolution measurement; and finally, carrying out online estimation on the high-dynamic distance delay deviation by using the speed ambiguity resolution measurement. The method can effectively solve the problem of high dynamic deviation estimation under the condition of range finding and speed measuring blur, and has a good effect when the target motion crosses the blur interval.
The invention solves the technical problem, and adopts the technical scheme that the steps are as follows:
step 1: under the condition of fuzzy distance measurement and speed measurement, target radial velocity estimation at multiple moments is obtained by using a distance difference method;
satisfy when considering that the target motion does not cross the fuzzy interval
Wherein r (k) is the target blur measurement, and R (k) is the target non-blur measurement. Then the radial velocity estimate of the target at multiple time instances can be expressed as
Where T is the sampling interval and m is the number of times.
Step 2: on the basis of obtaining the radial velocity estimation at a plurality of moments, judging whether the target motion crosses the fuzzy interval, and compensating the velocity estimation information crossing the fuzzy interval on the basis.
Considering target radial velocity estimation
Satisfy the condition of crossing and not crossing the fuzzy interval (taking the case that the target is far away from the radar as an example) respectively
Wherein R ismaxFor maximum unambiguous range, R when the target moves away from the radarmaxIs positive, R when the target moves towards the radarmaxIs negative; then a statistical decision quantity can be constructed
Furthermore, the problem of whether the target motion at the time k crosses the fuzzy interval can be further analyzed and judged by the following hypothesis test:
H0if η (i)>λ, the target motion crosses the fuzzy interval;
H1if η (i) is less than or equal to lambda, the target motion does not cross the fuzzy interval.
Wherein, λ is a speed sudden change judgment threshold and satisfies 0<λ<Rmax/T。
At this time, when the object does not move acrossEstimating radial velocity during fuzzy interval
No treatment is carried out; when the target motion crosses the fuzzy interval, the following compensation is carried out:
and step 3: and on the basis of the measurement compensation of the cross-fuzzy interval, smoothing the target radial velocity estimation at a plurality of moments by using a median filtering method so as to further obtain the velocity-resolved fuzzy measurement of the target.
1) The method using median filtering will
And sorting according to the sequence from small to large, and selecting the sorted middle value as the median value estimation of the target radial speed.
2) Combine the above median estimate to further obtain a deblurred measure of the target radial velocity
Wherein,is a deblurred measure of the target radial velocity, vamb(k) For the ambiguity speed measured by the radar,for a median estimate of the target radial velocity, vmaxIs the radar maximum unambiguous speed.
And 4, step 4: and compensating the high-dynamic distance delay deviation by using the speed ambiguity resolution measurement.
Obtaining velocity deblurring measurementsBased on the distance and the speed, the highly dynamic distance delay deviation estimation can be obtained through the coupling analysis of the distance and the speed
The beneficial effects of the invention are illustrated as follows: the invention processes radar measurement data by utilizing a recursive HT-TBD technology, performs recursive real-time update processing on an accumulation matrix and a storage array on the basis of obtaining an initial accumulation matrix and the storage array, not only can utilize the detection result of the previous moment to the maximum extent, improve the arithmetic efficiency of the algorithm and reduce the calculated amount, but also can realize real-time detection on the target, avoid missing detection of the target and have better detection effect.
And 5: and (4) repeating the steps 1-4 along with the time until all measurement processing is finished so as to realize the real-time estimation processing of the high dynamic deviation.
The beneficial effects of the invention are illustrated as follows: (1) the invention can effectively realize high dynamic deviation compensation processing under the condition of uniform ambiguity of distance measurement and speed measurement by using a method of combining distance difference and median filtering; (2) the method can be used for carrying out real-time on-line estimation on the high dynamic deviation, does not need to carry out complex distance ambiguity resolution, and can effectively realize effective estimation on the high dynamic deviation only by using single-repetition frequency ambiguity distance measurement.
Drawings
FIG. 1 is a flow chart of the method steps of the present invention;
FIG. 2 is a graph of the effect of the high dynamic bias of the present invention on radar detection;
FIG. 3 is a graph of the effect of high dynamic bias + measurement ambiguity on radar detection in accordance with the present invention;
FIG. 4 is a graph of the target radial velocity estimation results obtained by the distance differencing process of the present invention;
FIG. 5 is a graph of the radial velocity compensation results of the cross-ambiguity region processing of the present invention;
FIG. 6 is a graph of the radial velocity estimation results of the median filtering and velocity deblurring of the present invention;
FIG. 7 is a diagram of the high dynamic bias real-time estimation result of the present invention.
Detailed Description
The high dynamic deviation online estimation method under the condition of range measurement and velocity measurement blur is described below with reference to the accompanying drawings.
The implementation conditions are as follows: assuming that the initial position of the hypersonic target in the near space is 300km,300km,20km, the flying speed is 5000m/s, and the flying direction is 30 degrees off the west in the north. Accordingly, the position of the observation radar is [0km,0km,0km ], the radar wavelength is λ 0.15m, the chirp signal width is τ 600 μ s, the chirp bandwidth is B1.5 MHz, the distance, azimuth and pitch measurement errors of the radar are 100m, 0.1 ° and 0.1 °, respectively, and the observation period is 1 s. Referring to the attached figure 1, the specific implementation steps are as follows:
(1) the radar detects a target by using an LFM signal to obtain 30 frames of measurement data, wherein the influence of high dynamic deviation and measurement blurring on target measurement is shown in the attached figures 2 and 3;
(2) according to the step 1, carrying out difference processing on the fuzzy distance measurement of the targets at the adjacent moments to obtain target radial velocity estimation at a plurality of moments, wherein the target moves across fuzzy intervals in a 14 th frame, which is specifically shown in fig. 4;
(3) according to the step 2, through speed mutation judgment, finding out the radial speed of the cross-fuzzy interval appearing in the 14 th frame, and compensating the radial speed, wherein the radial speed is specifically shown in the attached figure 5;
(4) according to the step 3, performing median filtering processing on each radial velocity estimation, and obtaining a velocity deblurring measurement of the target on the basis, wherein the velocity deblurring measurement is specifically shown in the attached figure 6;
(5) according to step 4, the high dynamic bias is estimated by using the velocity deblurring measurement, which is specifically shown in fig. 7.
As can be seen from the analysis of fig. 2 and fig. 3, the high dynamic deviation causes the target measurement to deviate from the real track of the target seriously, and the measurement ambiguity not only causes the position of the target measurement to deviate, but also splits the complete target measurement into two segments, so that the detection performance of the radar is seriously affected by the composite influence of the high dynamic deviation and the measurement ambiguity; as can be seen from the analysis of fig. 4, the distance difference processing at adjacent times generates a large radial velocity jump when the target moves across the fuzzy interval, that is, the distance difference processing cannot be directly used to compensate the high dynamic deviation, and further processing is required; as can be seen from fig. 5, by detecting and compensating the abrupt change of the speed, the influence caused by the motion of the target across the fuzzy interval can be effectively eliminated; as can be seen from fig. 6, relatively smooth target radial velocity measurement can be effectively obtained through median filtering and velocity-deblurring processing of the target measurement; finally, as can be seen from fig. 7, the real-time estimation of the high dynamic deviation can be effectively realized by using the target radial velocity after the velocity deblurring processing.
Claims (5)
1. The high dynamic deviation online estimation method based on cross-fuzzy interval judgment under the condition of both ranging and speed measurement fuzzy is characterized by comprising the following steps of:
step 1: under the condition of fuzzy distance measurement and speed measurement, target radial velocity estimation at multiple moments is obtained by using a distance difference method;
step 2: on the basis of obtaining the radial velocity estimation of a plurality of moments, judging whether the target motion crosses a fuzzy interval by utilizing a method for carrying out mutation judgment on the radial velocity of adjacent moments, and compensating the radial velocity estimation of the cross fuzzy interval on the basis;
and step 3: on the basis of compensating the radial velocity estimation of the cross-fuzzy interval, smoothing the radial velocity estimation of a plurality of moments by using a median filtering method so as to further obtain the velocity deblurring measurement of the target;
and 4, step 4: and compensating the high-dynamic distance delay deviation by using the speed ambiguity resolution measurement.
2. The high dynamic bias online estimation method according to claim 1, characterized in that the following method is specifically adopted in step 1:
satisfy when considering that the target motion does not cross the fuzzy interval
Wherein, r (k) is the target fuzzy measurement, and R (k) is the target non-fuzzy measurement; then the radial velocity estimate of the target at multiple time instances is expressed as
Where T is the sampling interval and m is the number of times.
3. The high dynamic bias online estimation method according to claim 2, characterized in that the following method is specifically adopted in step 2:
considering target radial velocity estimation
When the fuzzy interval is not crossed, the condition is satisfied
Satisfy when crossing fuzzy interval
Wherein R ismaxTo the maximum unambiguous distance, a statistical decision quantity is constructed
Furthermore, the problem of whether the target motion at the time k crosses the fuzzy interval can be further analyzed and judged by the following hypothesis test:
H0if η (k) > lambda, the target moves across the fuzzy interval;
H1if η (k) is less than or equal to lambda, the target motion does not cross the fuzzy interval;
wherein, lambda is a speed mutation judgment threshold and satisfies that lambda is more than 0 and less than Rmax/T；
At this time, when the target motion does not cross the fuzzy interval, the radial velocity is estimated
No treatment is carried out; when the target motion crosses the fuzzy interval, the following compensation is carried out:
4. the high dynamic bias online estimation method according to claim 2, characterized in that the following method is specifically adopted in step 3:
1) the method using median filtering will
Sorting according to the sequence from small to large, and selecting the sorted middle value as the median value estimation of the target radial velocity
2) Combine the above median estimate to further obtain a deblurred measure of the target radial velocity
Wherein,
is a deblurred measure of the target radial velocity, vamb(k) For the ambiguity speed measured by the radar,for a median estimate of the target radial velocity, vmaxIs the radar maximum unambiguous speed.
5. The high dynamic bias online estimation method according to claim 1, characterized in that, the following method is specifically adopted in step 4:
obtaining velocity deblurring measurements
Based on the distance-speed coupling analysis, the high dynamic deviation is completed
Real-time online estimation.
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