CN103777187B - Tracking before weak target detection based on traversal random Hough transformation - Google Patents

Abstract

The invention discloses a kind of based on traversal random Hough transformation weak target detection before tracking. First the present invention carries out clutter to all frame radar return data and suppresses the first threshold processing, and stores separately each frame and exceed the first threshold data; Secondly all radar return stacked datas that exceed the first thresholding are added to data space, in to data space, carrying out a little Hough when conversion the present invention proposes a kind of thought that travels through pairing, and all differences in data space are matched to the method for straight line parameter asked for one by one; Then to traveling through a little Hough conversion in data space, ask for straight line parameter; Then required straight line parameter is voted. Finally extract ballot and be worth maximum straight line parameter, realize flight path and recall. The present invention can realize detection and the tracking of weak target under complex background environment, has good detection performance and tracking accuracy simultaneously.

Description

Tracking before weak target detection based on traversal random Hough transformation

Technical field

The invention belongs to radar data process field, relate to a kind of based on traversal random Hough transformationTracking before weak target detection.

Background technology

The timely detection of low signal-to-noise ratio target and accurately Continuous Tracking problem are radar-probing system needsOne of key technology solving. After traditional detection, follow the tracks of, judge that by thresholding is set single frames target isNo existence, follows the tracks of detecting after target again. This method has in the time that target signal to noise ratio is higherDetect preferably tracking performance, but in the time that target signal to noise ratio is lower, because target is submerged in clutter letterIn number, utilize this kind of method to detect and follow the tracks of the loss that will cause echo signal target, unfavorableTarget detection under low signal-to-noise ratio environment is followed the tracks of. Before detecting, tracking TBD is radar weak targetDetect a kind of effective ways (TrackBeforeDetect, TBD) of following the tracks of, it does not do original metric dataThreshold processing or adopt less thresholding, by the mode of multiframe energy accumulation improve target signal to noise ratio fromAnd realize the raising of the detectability of surveillance radar to target, in the time obtaining testing result, announce to follow simultaneouslyTrack result. Its essence is and exchange energy for the time, improve the signal to noise ratio of target. Convert based on HoughTBD method do not need target prior information, can the backward energy that come from same target be carried out non-Coherent accumulation, strengthens target signal to noise ratio, and then detects weak target signal. Due to standard HoughConvert required computing time and memory space larger, thereby researcher is below this technical changingEnter, proposed random Hough transformation, revised the technology such as Hough conversion and Generalized Hough Transform.Tradition random Hough transformation detects targetpath from the cumulative echo data midplane of multiframe stack,The method of target data not being chosen in addition any constraint, can cause detection probability lower, false boatThe situation that mark is on the high side, the straight line parameter in the table of dynamic link simultaneously just can not change after selecting, to falling intoPoint in its certain error is voted, and finds optimal solution for traversal dynamic link table, recovers like thisWill there is larger deviation with true flight path in the flight path coming. For these problems, random based on traversalThe all threshold data excessively of Hough transfer pair travel through pairing and ask for straight line parameter, then from every frame radarIn echo data, choose and have the method for contribution point to realize recalling of flight path to straight line parameter. This methodThere is higher detection probability, and can also avoid occurring the situation of false dismissal.

Summary of the invention

The present invention is directed to the deficiencies in the prior art, provide a kind of based on traversal random Hough transformationTracking before weak target detection. The method has solved the existing target based on random Hough transformationThe detection probability existing in tracking before detecting is not high, easily occurs the problem of false-alarm. Can enter simultaneouslyOne step improves tracking accuracy.

The present invention includes following steps:

(1) Hough parameter space is carried out to quantification treatment.

(2) the radar return data that exceed the first thresholding different k frame in each emulation are stored respectivelyIn the different matrix of K, the storage matrix that wherein k frame exceedes the first threshold data is expressed asz_k。

(3) stacked data of all frames being crossed to the first thresholding is added in datum plane W, and to allTravel through and ask for straight line parameter (ρ, θ) with data point, and put into dynamic link Table A.

(4) the straight line parameter in dynamic link table is contrasted to ballot one by one, if both meet oneDetermine error range, the ballot value of selected parameter value in dynamic link Table A is added to 1.

(5) ask in A ballot value maximum point and extract last straight line parameter value (ρ, θ).

(6) according to straight line parameter (ρ, θ), each single frames cross in the first thresholding echo data, extract rightRequired parameter has contribution point.

(7) realize the estimation to dbjective state according to required point.

(8) flight path is recalled, and shows tracking results, prepares to accept next group multiframe data.

Key technology of the present invention is to travel through the different pieces of information in paired data space, asks for straight line ginsengNumber. Dynamic link table is relatively ballot mutually, chooses optimal straight line parameter; Single frames extracts data and recalls orderMark flight path. The present invention has two advantages compared with traditional random Hough transformation: (1), detect generalRate is higher, because its traversal has been matched all data in datum plane, thereby has utilized institute likelyBe the information of target position data, having avoided in traditional random Hough transformation is not target trajectory 2 pointsThe problem of parameter influence detection probability is asked in pairing; (2), single frames is recalled flight path. Tradition random HoughIn conversion, during to the recalling of targetpath, in datum plane, extract the side that targetpath is had to contribution pointMethod, when thresholding being set when too high, target actual position information is not stored, thereby causes the feelings of false dismissalCondition. Select single frames radar return data to carry out target while recalling, can store Multi simulation running metric data,And then the phenomenon of avoiding target location to be dropped.

Brief description of the drawings

Fig. 1 is flow chart of the present invention.

Detailed description of the invention

Below in conjunction with Fig. 1, step of the present invention is made the following instructions:

Step 1. parameter space quantizes.

Hough conversion is that θ asks for to straight line parameter ρ, so utilize based on Hough conversionFirst TBD method is carried out realize target detection tracking will carry out quantification treatment to Hough parameter space.

θ_n＝(n-1/2)Δθn＝1,2…,N_θ（1）

ρ_n＝(n-1/2)Δρn＝1,2…,Nρ

Wherein Δ θ=π/N_θ，N_θFor the hop count of cutting apart of parameter θ; Δ ρ=L/N_ρ，L＝sqrt(n_x ²+n_y ²)，n_xAnd n_yFor the corresponding dimension in radar data space, N ρ is that parameter ρ is cut apartHop count.

Step 2. echo data does threshold processing and single frames is exceeded to the radar return data of the first thresholdingBe stored in different matrixes.

Radar return data are carried out to Hough conversion, obtain target component. Realistic objective is being carried outWhen processing, in order to reduce computing time and to reduce false alarm rate, so introduce the first thresholding η.

The radar return data that each frame exceeded to the first thresholding are stored in respectively in different z matrixes.

z_k＝(x_i,k,y_i,k)1≤k≤K1≤i≤l_k（2）

z_kRepresent all the first threshold data positional information set, (x of exceeding of k frame_i,k,y_i,k) be k frameThe positional information of i data of data, l_kBe that k frame data exceed the first threshold data number.

Step 3. is all the first threshold data data spaces that are added to that exceed

All stacked datas are added to datum plane W. If different frame data are identical in additive processAll there is target in position, chooses in different frame target amplitude maximum as the amplitude of this positionValue, and its correspondence position information is stored in matrix U.

U_i＝(x_i,y_i)1≤i≤L（3）

In formula, L is the number of data space mid point.

Step 4. traversal is asked for straight line parameter, and putting into one by one dynamic link table

Then according to formula (4) and (5), the Hough that travels through a little in U is converted, will ask at every turnThe straight line parameter of getting stores dynamic link Table A successively into.

$\left\{\begin{array}{cc}\mathrm{\ρ}=x_i\cos \left(\mathrm{\θ}\right)+y_i\sin \left(\mathrm{\θ}\right)& 1\≤i\≤L-1\\ \mathrm{\ρ}=x_j\cos \left(\mathrm{\θ}\right)+y_j\sin \left(\mathrm{\θ}\right)& i\≤j\≤L\end{array}\right.---\left(4\right)$

$\left\{\begin{array}{c}\mathrm{\θ}={\mathrm{tg}}^{-1}\left(\frac{x_j-x_i}{y_j-y_i}\right)\\ \mathrm{\ρ}=\left(\begin{array}{c}{x}_i\cos \left(\mathrm{\θ}\right)+y_i\sin \left(\mathrm{\θ}\right)+\\ x_j\cos \left(\mathrm{\θ}\right)+y_i\sin \left(\mathrm{\θ}\right)\end{array}\right)/2\end{array}\right.---\left(5\right)$

Step 5. is voted to the straight line parameter in dynamic link table, extracts ballot value maximum point.

Traversal pairing finishes rear data in Table A to be voted one by one according to formula (6). If in Table A twoBetween straight line parameter, meet certain error α and β, its corresponding ballot value is added to 1.

|ρ_i-ρ_j|≤α,|θ_i-θ_j|≤β1≤i＜j≤N（6）

A(ρ_i,θ_i)＝A(ρ_i,θ_i)+1

In formula, i and j are respectively i and j parameter value in table, and N is number of parameters in Table A.

Extract maximum ballot value parameter (ρ, θ) in Table A, if there be M the ginseng that ballot is maximum in Table ANumber, is weighted and on average tries to achieve optimum (ρ, θ) it according to following formula.

$(\mathrm{\ρ},\mathrm{\θ})=\underset{i=1}{\overset{M}{\mathrm{\Σ}}}({\mathrm{\ρ}}_i,{\mathrm{\θ}}_i)/M---\left(7\right)$

Step 6. is extracted has contribution data to straight line parameter, estimating target state.

Utilize required straight line parameter to extract in each frame the contributive point of straight line parameter storage by formula (8)In matrix S:

|ρ-x_i,kcos(θ)-y_i,ksin(θ)|≤mΔρ1≤i≤l_k（8）

S_k＝(x_i,k,y_j,k)1≤i≤l_k,1≤k≤K

In formula, m is positive integer. According to the data in S, dbjective state is estimated, and by estimated valueBe stored in B.

Step 7., according to dbjective state matrix B export target flight path, prepares to accept next group data.

Claims (1)

1. tracking before the weak target detection based on traversal random Hough transformation, is characterized in that the partyMethod comprises the following steps:

Step 1, Hough parameter space is carried out to quantification treatment;

Step 2, the radar return data that exceed the first thresholding different K frame in each emulation are deposited respectivelyStorage is in the different matrix of K, and the storage matrix that wherein k frame exceedes the first threshold data is expressed as z_k；

Step 3, the stacked data that all frames are crossed to the first thresholding are added in datum plane W, and to allTravel through and ask for straight line parameter (ρ, θ) with data point, and put into dynamic link Table A;

Step 4, the straight line parameter in dynamic link table is contrasted to ballot one by one, if both meet oneDetermine error range, the ballot value of selected parameter value in dynamic link Table A is added to 1;

Step 5, ask in dynamic link Table A ballot value maximum point and extract last straight line parameter value(ρ，θ)；

Step 6, according to straight line parameter (ρ, θ), each single frames cross in the first thresholding echo data, extract rightRequired parameter has contribution point;

Step 7, according to extract the some estimation realizing dbjective state;

Step 8, flight path are recalled, and show tracking results, prepare to accept next group multiframe data.