METHOD FOR CALCULATING GATING SCORES IN PULSE-DOPPLER RADAR SYSTEMS USING A FUSION OF POSITION, POWER, DETECTION SIZE AND AMBIGUOUS DOPPLER MEASUREMENT DATA

Abstract

The invention relates to a method of calculating gating scores in the pulse-Doppler radar using a combination of position, power, size of detection and ambiguous Doppler measurement data to effectively overcome the phenomenon of wrongly assigning detections to the target trajectory and creating false targets in noise regions. The method intelligently merges position, power, detection size and ambiguous Doppler measurement data information of the detections in the algorithm of calculating gating score to solve the problem of selection and disputation detections. The method is carried out through two steps, step 1: determine statistical quantities from the standard data set; step 2: gating selection algorithm.

Claims

1. A method of calculating a gating score and assigning detection-trajectory on pulse-Doppler radar using a combination of position, power, detection size and ambiguous Doppler frequency shift includes 2 steps: step 1: determine statistical quantities from a standard data set; step 1: determine statistical quantities from the standard data set: collect a data set of radar targets that are paired with ground-truth data based on similarity of position, trajectory, velocity and direction of movement (heading angle); statistics quantities to be determined from the standard data set include: mean and standard deviation of the Doppler difference values, power difference values, detection size difference values; a cut threshold value for the Doppler difference distance, power difference distance, detection size difference distance and position distance; step 2: perform a gating selection algorithm: determine a radial velocity from a range and a timestamp; determine an estimated Doppler value from the radial velocity; determine a Doppler difference, power difference and detection size difference; determine a Doppler difference distance, power difference distance, detection size difference distance and position distance; calculate a score value for each distance value; normalize the score value; calculate a total gating sore for the detection; the total gating score value of the detection in the gate of all tracks is put into an auction algorithm to select a most appropriate track-to-detection.

2. The method of calculating a gating score and assigning detection-trajectory on pulse-Doppler radar using a combination of position, power, detection size and ambiguous Doppler frequency shift according to claim 1, in which: calculate the radial velocity and the estimated Doppler value: determine the radial velocity using the range and timestamp of N consecutive samples in the following formula: ${\mathrm{rr}}_i=\frac{1}{N}*\left(\frac{r_{i-N+1}-r_{i-N+2}}{t_{i-N+2}-t_{i-N+1}}+\frac{r_{i-N+2}-r_{i-N+3}}{t_{i-N+3}-t_{i-N+2}}+.Math.+\frac{r_{i-1}-r_i}{t_i-t_{i-1}}\right)$ where: rr: radial velocity, unit: m/s r: range, unit: m t: timestamp, unit: s i: sample i.sup.th N is an integer selected depending on maneuverability of the radar target and the data update cycle of the radar, the less maneuvering the target or the faster the target data update, the greater N can be chosen, in common situations, N is in the range of 2-4; the timestamp is taken directly from an Analog-to-Digital module of a hardware device to increase accuracy of calculating the value of the radial velocity; the estimated Doppler is calculated from the radial velocity according to the following formula: $\mathrm{DopplerAbs}=\mathrm{mod}\left(\frac{rr}{{}_d},M\right)$ if the Doppler increases clockwise with an original bank F.sub.0, $=\mathrm{mod}\left(F_0+\mathrm{DopplerAbs},M\right)$ if the Doppler increases counter-clockwise with the original bank F.sub.0, $=\{\begin{array}{cc}{F}_0-\mathrm{DopplerA}\mathrm{bs}& n{\hat{e}}^{}u{F}_0\mathrm{DopplerA}\mathrm{bs}\\ F_0+M-\mathrm{DopplerA}\mathrm{bs}& n{\hat{e}}^{}u{F}_0<\mathrm{DopplerA}\mathrm{bs}\end{array}.$

3. The method of calculating the gating score and assigning detection-trajectory on pulse-Doppler radar using a combination of position, power, detection size and ambiguous Doppler frequency shift according to claim 1, in which: utilizing Doppler difference values, power difference values and detection size difference values in the gating selection algorithm; using Doppler, power and detection size information is that assuming y.sup.i is the detection of the target at the time i, the value of the estimated Doppler from the radial velocity will be approximately equal to the measured Doppler at the time i; similarly, the value of the measured power at the time i will be approximately equal to the mean power of the target, the power value used to calculate is a normalized value regardless of the range; the value of the detection size at the time i will be approximately equal to a mean size value of the target's historical rounds; determine Doppler difference: $F_D=.Math.F_D-.Math.$ $\mathrm{if}{F}_D>N/2:$ $F_D=N-F_D$ the use of the Doppler difference is completely unwavering by the Doppler ambiguity problem; calculate the power difference: $P=.Math.P-\stackrel{}{P}.Math.$ calculate the detection size difference: $\mathrm{Si}=.Math.\mathrm{Si}-\stackrel{}{S_l}.Math..$

4. The method of calculating the gating score and assigning detection-trajectory on pulse-Doppler radar using a combination of position, power, detection size and ambiguous Doppler frequency shift according to claim 1, in which: calculate Doppler difference distance, power difference distance, detection size difference distance, position distance, specifically: Doppler difference distance from a point F.sub.D to a distribution of Doppler difference values is calculated according to the following formula: $d_{F_D}=\sqrt{\left(F_D-{}_{F_D}\right){\left(S_{F_D}^2\right)}^{-1}{\left(F_D-{}_{F_D}\right)}^{-1}}$ power difference distance: $d_P=\sqrt{\left(P-{}_P\right){\left(S_P^2\right)}^{-1}{\left(P-{}_P\right)}^{-1}}$ detection size difference distance: $d_{Si}=\sqrt{\left(Si-{}_{Si}\right){\left(S_{Si}^2\right)}^{-1}{\left(Si-{}_{Si}\right)}^{-1}}$ position distance: $d_p=\sqrt{\left(p-{}_p\right){{}^{-1}\left(p-{}_p\right)}^{-1}}.$

5. The method of calculating the gating score and assigning detection-trajectory on pulse-Doppler radar using a combination of position, power, detection size and ambiguous Doppler frequency shift according to claim 1, in which: the method of calculating the score value of each detection in the gating is carried out sequentially through 7 steps: step 1, determine the radial velocity; step 2, determine the estimated Doppler from the radial velocity; step 3, determine the Doppler difference, power difference, detection size difference; step 4, determine the Doppler difference distance, power difference distance, detection size difference distance and position distance; step 5, calculate the score value for each distance value in step 4; step 6, normalize the score value in step 5; step 7, calculate the total sore for the detection; perform auction algorithm.

6. The method of calculating the gating score and assigning detection-trajectory on pulse-Doppler radar using a combination of position, power, detection size and ambiguous Doppler frequency shift according to claim 1, in which: calculate score value for the Doppler difference distance: ${\mathrm{score}}_{F_D}=\{\begin{array}{cc}{\mathrm{thres}}_{F_D}-d_{F_D}& \mathrm{if}{d}_{F_D}<{\mathrm{thres}}_{F_D}\\ 0& \mathrm{if}{d}_{F_D}>{\mathrm{thres}}_{F_D}\end{array}$ the cut threshold of the Doppler difference distance thres.sub.F.sub.D is determined by: ${\mathrm{thres}}_{F_D}=F^{-1}\left(95\%\right)$ where F is a cumulative distribution function of Doppler difference distance distribution calculate score value for power difference distance: ${\mathrm{score}}_P=\{\begin{array}{cc}{\mathrm{thres}}_P-d_P& \mathrm{if}{d}_P<{\mathrm{thres}}_P\\ 0& \mathrm{if}{d}_P>{\mathrm{thres}}_P\end{array}$ the cut threshold of the power difference distance thres.sub.P is determined so that covers 95% of the values of the power difference distance distribution; calculate score value for the detection size difference distance: ${\mathrm{score}}_{\mathrm{Si}}=\{\begin{array}{cc}{\mathrm{thres}}_{\mathrm{Si}}-d_{\mathrm{Si}}& \mathrm{if}{d}_{\mathrm{Si}}<{\mathrm{thres}}_{\mathrm{Si}}\\ 0& \mathrm{if}{d}_{\mathrm{Si}}>{\mathrm{thres}}_{\mathrm{Si}}\end{array}$ the cut threshold of the detection size difference distance thres.sub.Si is determined so that covers 95% of the values of the size difference distance distribution; calculate score value for the position distance: ${\mathrm{score}}_p=\{\begin{array}{cc}{\mathrm{thres}}_p-d_p& \mathrm{if}{d}_p<{\mathrm{thres}}_p\\ 0& \mathrm{if}{d}_p>{\mathrm{thres}}_p\end{array}.$

7. The method of calculating the gating score and assigning detection-trajectory on pulse-Doppler radar using a combination of position, power, detection size and ambiguous Doppler frequency shift according to claim 1, in which: Method of normalizing the score value, Doppler, power and detection size are used to complement the position information to enhance the efficiency of the detection score calculation function, so the score values must be normalized in the range of [0-q]: ${\mathrm{score}}_{F_{D_{\mathrm{norm}}}}=\frac{{\mathrm{score}}_{F_D}*q}{{\mathrm{thres}}_{F_D}}$ $\mathrm{scor}{e}_{P_{\mathrm{norm}}}=\frac{{\mathrm{score}}_P*q}{{\mathrm{thres}}_P}$ $\mathrm{scor}{e}_{S{i}_{\mathrm{norm}}}=\frac{{\mathrm{score}}_{Si}*q}{{\mathrm{thres}}_{Si}}$ where q=q.sub.max/3 and q.sub.max is the maximum value of the position distance scores.

8. The method of calculating the gating score and assigning detection-trajectory on pulse-Doppler radar using a combination of position, power, detection size and ambiguous Doppler frequency shift according to claim 1, in which: determine the total score value of each detection in the target trajectory gate using the combination of 4 score values of the Doppler difference distance, the power difference distance, detection size difference distance and the position distance, the weights of score.sub.F.sub.Dnorm, score.sub.P.sub.norm and score.sub.Si.sub.norm are chosen depending on the measurement accuracy of each quantity in the radar system; $\mathrm{Score}={\mathrm{score}}_p+w_{\mathrm{Doppler}}*{\mathrm{score}}_{F_{D_{\mathrm{norm}}}}+w_{\mathrm{Power}}*{\mathrm{score}}_{P_{\mathrm{norm}}}$ $\mathrm{where}{w}_{\mathrm{Doppler}},w_{Power}\mathrm{and}{w}_{Size}\mathrm{are}\mathrm{weights}\mathrm{of}{\mathrm{score}}_{F_{D_{\mathrm{norm}}}},{\mathrm{score}}_{P_{\mathrm{norm}}}\mathrm{and}{\mathrm{score}}_{S{i}_{norm}},\mathrm{respectively};$ $w_{\mathrm{Doppler}}+w_{\mathrm{Power}}+w_{Size}=1$ the value of the weights depends on the measurement accuracy of each quantity Doppler, power and detection size in the radar system, the higher the value of this score, the more suitable the detection to assign the target trajectory.

Description

DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1: diagram of the implementation steps of the method of calculating gating score and selecting detection-trajectory on the pulse-Doppler radar using a combination of position, power, detection size and ambiguous Doppler frequency shift;

[0011] FIG. 2: steps to calculate the mean and standard deviation of Doppler difference, power difference and detection size difference;

[0012] FIG. 3: steps to determine threshold values for Doppler difference distance, power difference distance, detection size difference distance and position distance;

[0013] FIG. 4: implementation steps of the gating selection algorithm; and

[0014] FIG. 5: the result of the gating score value of the detections in the target window of the traditional method and the proposed method.

DETAILED DESCRIPTION

[0015] The invention provides the method of improving the accuracy of the multi-target tracking system on the pulse-Doppler radar using a combination of position, Doppler and power measurements in both the trajectory management and detection-trajectory correlation blocks.

[0016] The invention employs incorporating position, power, detection size and Doppler in the gating selection algorithm. The steps to implement this approach are illustrated in FIG. 1. A comprehensive breakdown of the method's procedure is outlined in the following section:

Step 1: Determine Statistical Quantities from the Standard Data Set

[0017] Collect a data set of radar targets that are paired with ground-truth data based on similarity of position, trajectory, velocity and direction of movement (heading).

[0018] Refer to FIG. 1, statistics quantities to be determined from the standard data set include: mean and standard deviation of the Doppler difference values, power difference values, detection size difference; the cut threshold value for the Doppler difference distance, power difference distance, detection size difference distance and position distance. [0019] Refer to FIG. 2, block (201) shows steps for determining the mean and variance for the Doppler difference values. [0020] Calculate the radial velocity (201a):
Determine the radial velocity using the range and timestamp of the N consecutive samples in the following formula:

[00001]${\mathrm{rr}}_i=\frac{1}{N}*\left(\frac{r_{i-N+1}-r_{i-N+2}}{t_{i-N+2}-t_{i-N+1}}+\frac{r_{i-N+2}-r_{i-N+3}}{t_{i-N+3}-t_{i-N+2}}+.Math.+\frac{r_{i-1}-r_i}{t_i-t_{i-1}}\right)$

Where:

[0021] rr: radial velocity, unit: m/s [0022] r: range, unit: m [0023] t: timestamp, unit: s [0024] i: i.sup.th sample [0025] N is the integer selected depending on the maneuverability of the target and the radar update rate. The less maneuver the target or the faster the radar update rate, the greater N can choose. In common situations, we propose to use N in the range of 2-4.
The timestamp is taken directly from the Analog-to-Digital module of the hardware device to increase the accuracy of calculating the value of the radial velocity. [0026] Calculate the estimated Doppler from the radial velocity (201b):
The estimated Doppler is calculated from the radial velocity according to the following formula:

[00002]$\mathrm{Doppler}\mathrm{Abs}=\mathrm{mod}\left(\frac{\mathrm{rr}}{v_d},M\right)$

Where:

[0027] DopplerAbs: the absolute estimated Doppler value [0028] v.sub.d: Doppler resolution (m/s) [0029] M: the total number of Doppler banks processed [0030] + If the Doppler increases clockwise with the original bank F.sub.0,

[00003]$=\mathrm{mod}\left(F_0+\mathrm{Doppler}\mathrm{Abs},M\right)$

where: [0031] : the estimated Doppler [0032] F.sub.0: the original bank value [0033] + If the Doppler increases counter-clockwise with the original bank F.sub.0,

[00004]$=\{\begin{array}{cc}{F}_0-\mathrm{Doppler}\mathrm{Abs}& \mathrm{if}{F}_0\mathrm{Doppler}\mathrm{Abs}\\ F_0+M-\mathrm{Doppler}\mathrm{Abs}& \mathrm{if}{F}_0<\mathrm{Doppler}\mathrm{Abs}\end{array}$ [0034] Determine Doppler difference (201c):

[0035] The main idea of using Doppler information is that assuming y.sup.i is the detection of the target at the time i, the value of the estimated Doppler from the radial velocity will be approximately equal to the measured Doppler at the time i.

The Doppler difference is calculated as follows:

[00005]$F_D=.Math.F_D-.Math.$$\mathrm{If}$$F_D>M/2:$$F_D=M-F_D$

Where:

[0036] F.sub.D: Doppler difference [0037] F.sub.D: the measured Doppler of the detection
The use of the Doppler difference is completely unwavering by the Doppler ambiguity problem. [0038] Calculate mean and variance of Doppler difference values (201d):

[00006]${}_{F_D}=\frac{1}{K}\underset{k=1}{\overset{K}{.Math.}}{F}_{D_k}$$S_{F_D}^2=\frac{1}{K}\underset{k=1}{\overset{K}{.Math.}}{\left(F_{D_k}-{}_{F_D}\right)}^2$

Where:

[0039] .sub.F.sub.D: mean of Doppler difference values [0040] S.sub.F.sub.D.sup.2: variance of Doppler difference values [0041] K: size of Doppler difference value set [0042] Refer to FIG. 2, block (202) shows steps for determining the mean and variance for the power difference values.

[0043] Similarly, the main idea of using power information is that assuming y.sup.i is the detection of the target at the time i, the value of the measured power at the time i will be approximately equal to the mean power of the target. In particular, the power value used to calculate is the normalized value regardless of the range. [0044] Calculate the power difference value (202a):

[00007]$P=.Math.P-\stackrel{}{P}.Math.$

Where:

[0045] P: power difference [0046] P: the measured power [0047] P: the mean power [0048] Calculate mean and variance of power difference values (202b):

[00008]${}_P=\frac{1}{K}\underset{k=1}{\overset{K}{.Math.}}{P}_k$$S_P^2=\frac{1}{K}\underset{k=1}{\overset{K}{.Math.}}{\left(P_k-{}_P\right)}^2$

Where:

[0049] .sub.P: mean of power difference values [0050] S.sub.P.sup.2: variance of power difference values [0051] Refer to FIG. 2, block (203) shows steps for determining the mean and variance for the detection size difference values.

[0052] The size of the radar detection remains consistent over time and varies with the type of object and the distance from which it is observed. In high-resolution radars, the detection size is also proportional to the size of the target being observed. The main idea of using detection size information is that assuming y.sup.i is the detection of the target at the time i, the value of the detection size at the time i will be approximately equal to the mean size of the target. [0053] Calculate the detection size difference value (202a):

[00009]$\mathrm{Si}=.Math.\mathrm{Si}-\stackrel{\_}{S\mathrm{.Math.}}.Math.$

Where:

[0054] Si: detection size difference [0055] Si: the measured detection size [0056] Si: the mean detection size [0057] Calculate mean and variance of detection size difference values (203b):

[00010]${}_{\mathrm{Si}}=\frac{1}{K}\underset{k=1}{\overset{K}{.Math.}}{\mathrm{Si}}_k$$S_{\mathrm{Si}}^2=\frac{1}{K}\underset{k=1}{\overset{K}{.Math.}}{\left({\mathrm{Si}}_k-{}_{\mathrm{Si}}\right)}^2$

Where:

[0058] .sub.Si: mean of size difference values [0059] S.sub.Si.sup.2: variance of size difference values. [0060] Refer to FIG. 3, block (301) shows steps of determining the cut threshold for Doppler difference distance. [0061] The Doppler difference distance is calculated according to the following formula (301a):

[00011]$d_{F_D}=\sqrt{\left(F_D-{}_{F_D}\right){\left(S_{F_D}^2\right)}^{-1}{\left(F_D-{}_{F_D}\right)}^{-1}}$

Where, d.sub.F.sub.D is Doppler difference distance. [0062] Determine distribution for the Doppler difference distance values (301b):
Assuming the set of Doppler difference distance values follows a certain distribution P, it is necessary to test the statistical hypothesis: [0063] H.sub.0: the set of Doppler difference distance values follows the P distribution [0064] H.sub.1: the set of Doppler difference distance values does not follow the P distribution
Using Chi-square goodness-of-fit test with 5% significance level, if p-value is greater than 5%, the hypothesis H.sub.0 cannot be rejected, it means the set of Doppler difference distance values follows the P distribution. [0065] The cut threshold of the Doppler difference distance (301c) is determined by:

[00012]${\mathrm{thres}}_{F_D}=F^{-1}\left(95\%\right)$

Where F is the cumulative distribution function of Doppler difference distance distribution. [0066] Refer to FIG. 3, block (302) shows steps of determining the cut threshold for power difference distance. [0067] The power difference distance (302a) is calculated according to the following formula:

[00013]$d_P=\sqrt{\left(P-{}_P\right){\left(S_P^2\right)}^{-1}{\left(P-{}_P\right)}^{-1}}$ [0068] The method of determining distribution (302b) and cut threshold value thres.sub.P (302c) for the power difference distance is done the same as the method of determining the distribution and the cut threshold for the set of Doppler difference distance values. [0069] Refer to FIG. 3, block (303) shows steps of determining the cut threshold for detection size difference distance. [0070] The size difference distance (303a) is calculated according to the following formula:

[00014]$d_{Si}=\sqrt{\left(Si-{}_{Si}\right){\left(S_{Si}^2\right)}^{-1}{\left(Si-{}_{Si}\right)}^{-1}}$ [0071] The method of determining distribution (303b) and cut threshold value thres.sub.Si (303c) for the size difference distance is done the same as the method of determining the distribution and the cut threshold for the set of Doppler difference distance values. [0072] Refer to FIG. 3, block (304) shows steps of determining the cut threshold for position distance. [0073] Position distance d.sub.p (304a) is determined by:

[00015]$d_p=\sqrt{\left(p-{}_p\right){{}^{-1}\left(p-{}_p\right)}^{-1}}$

Where:

[0074] p: position vector (including x, y, z coordinates converted from range, azimuth and elevation) [0075] .sub.p: predicted position vector of the tracking filter [0076] : predicted covariance matrix of the tracking filter [0077] The method of determining distribution (304b) and cut threshold value thres.sub.p (304c) for the position distance is done the same as the method of determining the distribution and the cut threshold for the set of Doppler difference distance values.

Step 2: The Gating Selection Algorithm

Refer to FIG. 4, the gating selection algorithm is carried out sequentially through the following steps: [0078] Determine the radial velocity (401):
The method for determining the radial velocity value has been presented in step 1. [0079] Determine the estimated Doppler from the radial velocity (402):
The method for determining the estimated Doppler has been presented in step 1. [0080] Determine the Doppler difference, power difference and detection size difference (403):
The method for determining the Doppler difference, power difference and detection size difference have been presented in step 1. [0081] Determine the Doppler difference distance, power difference distance, detection size difference distance and position distance (404):
The method for determining the Doppler difference distance, power difference distance, detection size difference distance and position distance have been presented in step 1. [0082] Calculate the score value for each distance value (405) [0083] + The score value for the Doppler difference distance score.sub.F.sub.D is calculated using the following form:

[00016]${\mathrm{score}}_{F_D}=\{\begin{array}{cc}\left({\mathrm{thres}}_{F_D}-d_{F_D}\right)& \mathrm{if}{d}_{F_D}<{\mathrm{thres}}_{F_D}\\ 0& \mathrm{if}{d}_{F_D}>{\mathrm{thres}}_{F_D}\end{array}$ [0084] + The score value for the power difference distance score.sub.P is calculated according to the following formula:

[00017]${\mathrm{score}}_P=\{\begin{array}{cc}\left({\mathrm{thres}}_P-d_P\right)& \mathrm{if}{d}_P<{\mathrm{thres}}_P\\ 0& \mathrm{if}{d}_P>{\mathrm{thres}}_P\end{array}$ [0085] + The score value for the size difference distance score.sub.Si is calculated according to the following formula:

[00018]${\mathrm{score}}_{Si}=\{\begin{array}{cc}\left({\mathrm{thres}}_{\mathrm{Si}}-d_{\mathrm{Si}}\right)& \mathrm{if}{d}_{\mathrm{Si}}<{\mathrm{thres}}_{\mathrm{Si}}\\ 0& \mathrm{if}{d}_{\mathrm{Si}}>{\mathrm{thres}}_{\mathrm{Si}}\end{array}$ [0086] + The score value for the position distance score, can be derived as:

[00019]${\mathrm{score}}_p=\{\begin{array}{cc}\left({\mathrm{thres}}_p-d_p\right)& \mathrm{if}{d}_p<{\mathrm{thres}}_p\\ 0& \mathrm{if}{d}_p>{\mathrm{thres}}_p\end{array}$ [0087] Normalize the score value (406)

[0088] Because Doppler, detection size and power are used to complement the position information to enhance the efficiency of the detection score calculation function, the score values must be normalized in the range of [0-q]:

[00020]${\mathrm{score}}_{F_{D_{norm}}}=\frac{{\mathrm{score}}_{F_D}*q}{{\mathrm{thres}}_{F_D}}$$\mathrm{scor}{e}_{P_{norm}}=\frac{{\mathrm{score}}_P*q}{{\mathrm{thres}}_P}$$\mathrm{scor}{e}_{S{i}_{norm}}=\frac{{\mathrm{score}}_{Si}*q}{{\mathrm{thres}}_{Si}}$

Where q=q.sub.max/3 and q.sub.max is the maximum value of the position distance scores. [0089] Calculate the total sore for the detection (407)

[0090] The total score value TScore of the detection in the target gate shows the appropriate level of that detection for the target. The higher the value of this TScore value, the more suitable the detection to assign the target.

[00021]$\mathrm{TScore}={\mathrm{score}}_p+w_{Doppler}*scor{e}_{F_{D_{norm}}}+w_{Power}*scor{e}_{P_{norm}}$$\mathrm{Where}{w}_{Doppler}\mathrm{and}{w}_{Power}\mathrm{are}\mathrm{weights}\mathrm{of}{\mathrm{score}}_{F_{D_{norm}}}\mathrm{and}{\mathrm{score}}_{P_{norm}},\mathrm{repectively}.$$w_{\mathrm{Doppler}}+w_{Power}=1$

The value of the weights depends on the measurement accuracy of each quantity in the radar system. [0091] The auction algorithm:

[0092] The total score value of the detection in the gate of all tracks is put into the auction algorithm to select the most appropriate track-to-detection.

[0093] FIG. 5 shows the total score values of detections in the target gate for the traditional method (using only position) and the proposed method, the parameters and weights used are as follows, w.sub.Doppler=, w.sub.Power=, w.sub.Size=, q=0.45. The integrated use of position, power, detection size and ambiguous Doppler frequency shift in the gate selection algorithm gives better results than using only position information. The total score values of detections from targets are more clearly separated from those of noise. The Key Performance Indicator (KPI) of the proposed method is 25% higher than that of the traditional method. The KPI comparison quantity, determining the ratio of target detections with higher total score values than noise detections to the total number of samples considered, is calculated accordingly:

[00022]$\mathrm{KPI}=\frac{\begin{array}{c}\mathrm{the}\mathrm{number}\mathrm{of}\mathrm{samples}\mathrm{with}\mathrm{target}\mathrm{detection}\mathrm{total}\\ \mathrm{score}\mathrm{values}>\mathrm{noise}\mathrm{detection}\mathrm{total}\mathrm{score}\mathrm{values}\end{array}}{\mathrm{the}\mathrm{total}\mathrm{number}\mathrm{of}\mathrm{samples}}\left(\%\right)$