CN106093883A - The lower main distribution calculation method of principal subsidiary lobe ground and sea clutter of detection after tail is regarded under a kind of radar - Google Patents

Abstract

The invention discloses a kind of main distribution calculation method of principal subsidiary lobe ground and sea clutter, comprise the steps of and detect wave beam all directions gain power after regarding tail under radar, determine principal subsidiary lobe ground and sea clutter main distribution corresponding region；Choose corresponding clutter point in corresponding region, and calculate the position coordinates of all clutters point；The position coordinates of the position coordinates according to radar, velocity parameter and all clutters point, calculates all clutters point and the relative distance of radar and relative Doppler frequency；In conjunction with maximum unam, the pulse recurrence frequency parameter of radar emission signal, calculate apparent range and the apparent Doppler frequency of all clutters point；Quantify apparent range and the apparent Doppler frequency of all clutters point, and the quantized distance of all clutter points and quantization Doppler frequency are mapped to range-Dopler domain, obtain the accurate location of the main distribution of principal subsidiary lobe ground and sea clutter.The present invention calculates real-time, effectively promotes and regards detection power and tracking performance after tail under radar.

Description

The lower main distribution calculation method of principal subsidiary lobe ground and sea clutter of detection after tail is regarded under a kind of radar

Technical field

The present invention relates to regard under radar Detection Techniques field after tail, be specifically related under a kind of radar regard the lower major-minor of detection after tail The main distribution calculation method of lobe ground and sea clutter.

Background technology

Ground and sea clutter is to regard detection and the maximum restraining factors following the tracks of target capabilities after tail under radar.Regard down detection sky after tail Middle target, target echo signal falls into secondary lobe clutter district, and in radar emission, repetition rate waveform is used for detecting target.Relatively high heavy Complex frequency waveform, in employing, repetition rate waveform can reduce secondary lobe clutter distance aliasing degree, and further by distance dimension Cutting reduces secondary lobe clutter power, makes radar possess lower detectivity after tail.But due to secondary lobe clutter radar process away from On-Doppler domain and non-uniform Distribution, but there is strength distribution, when target echo signal falls into strong secondary lobe clutter region When, on the one hand greatly reduce detection signal to noise ratio, affect radar range；On the other hand radar error lock has been significantly greatly increased Or following the tracks of the probability of secondary lobe clutter, causing losing target, this situation needs improvement badly.

Content of the invention

It is an object of the invention to provide and under a kind of radar, regard detection lower principal subsidiary lobe ground and sea clutter main distribution calculating side after tail Method, can obtain main distribution accurate location on distance-Doppler territory for the ground and sea clutter in line computation, solve strong secondary lobe clutter tight Ghost image is thundering and reaches lower detection and the problem following the tracks of target capabilities after tail, is depending on making target echo during detection target after tail under radar Signal avoids strong secondary lobe clutter, it is to avoid falling into strong secondary lobe clutter region provides necessary reference conditions, effectively promotes and regards tail under radar Rear detection power and tracking performance.

In order to achieve the above object, the present invention is achieved through the following technical solutions: after regarding tail under a kind of radar, detection is lower main The main distribution calculation method of secondary lobe ground and sea clutter, is characterized in, comprises the steps of

S1, according to regarding under radar detection wave beam all directions gain after tail strong and weak, determine that the main distribution of principal subsidiary lobe ground and sea clutter is right Answer region；

S2, in principal subsidiary lobe ground and sea clutter main distribution corresponding region, choose corresponding clutter point, and calculate all clutters point Position coordinates；

S3, the position coordinates according to the position coordinates of radar, the velocity parameter of radar and all clutters point, calculate institute Have clutter point and the relative distance of radar and relative Doppler frequency；

The pulse recurrence frequency parameter of S4, the maximum unam combining radar emission signal and radar emission signal, Calculate apparent range and the apparent Doppler frequency of all clutters point；

S5, the apparent range quantifying all clutters point and apparent Doppler frequency, and by the quantized distance of all clutter points Map to distance-Doppler territory with quantifying Doppler frequency, obtain the accurate location of the main distribution of principal subsidiary lobe ground and sea clutter.

Described step S1 comprises:

S1.1, set up the frame of reference and platform coordinate system respectively；

S1.2, according to actual radar directional pattern strength distribution feature, with the sensing angle under platform coordinate system, arrange main Secondary lobe ground and sea clutter long distance boundary point is relative with radar antenna with low coverage boundary point to be pointed to, and according to radar under the frame of reference Position and attitude calculate long distance boundary point and coordinate under the frame of reference for the low coverage boundary point respectively；

S1.3, under the frame of reference, the line of long distance boundary point and low coverage boundary point is constituted principal subsidiary lobe ground and sea clutter The computation interval of main distribution corresponding region.

In described step S1.1, the initial point of the frame of reference is set on ground/sea, and X-axis is north orientation, and Y-axis is sky To Z axis is east orientation, and radar present position is defined as P_R, the coordinate under the frame of reference is (x_R, y_R, z_R), fixed according to the right hand Then determining radar attitude, radar attitude is defined as (Ψ, θ, γ), and Ψ represents yaw angle, and θ represents the angle of pitch, and γ represents roll angle.

The described platform coordinate system in step S1.1 is to radar present position by frame of reference origin translation, then will It carries out three times according to Ψ, θ, γ attitude angle successively and rotates, and obtains platform coordinate system P_RX " Y " Z ", points to angle (α, β) and represents thunder Reaching antenna beam, ground/sea location point and relative position relation in platform coordinate system for the radar, α represents azimuth, β table Show the angle of pitch.

In described step S1.2, Coordinate calculation method under the frame of reference for the long distance boundary point comprises:

Under platform coordinate system, long distance boundary point is pointed to angle and is calculated sensing unit vector；

Changed by Eulerian coordinates, be transformed into the sensing unit vector under platform coordinate system in the frame of reference, calculate Obtain pointing under the frame of reference unit vector；

By pointing to unit vector under the frame of reference, platform coordinate is calculated long distance boundary point under the frame of reference Coordinate.

In described step S1.2, Coordinate calculation method under the frame of reference for the low coverage boundary point comprises:

Under platform coordinate system, low coverage boundary point is pointed to angle and is calculated sensing unit vector；

Changed by Eulerian coordinates, be transformed into the sensing unit vector under platform coordinate system in the frame of reference, calculate Obtain pointing under the frame of reference unit vector；

By pointing to unit vector under the frame of reference, platform coordinate is calculated low coverage boundary point under the frame of reference Coordinate.

Described step S2 comprises:

Under the frame of reference, the coordinate of coordinate according to long distance boundary point and low coverage boundary point calculate long distance boundary point and The relative distance of low coverage boundary point；

Under the frame of reference, calculate long distance boundary point by the coordinate of long distance boundary point and the coordinate of low coverage boundary point and arrive Low coverage boundary point line and the angle of Z axis；

Set and take a number on long distance boundary point and low coverage boundary point line, calculate each selected point successively relative to low coverage limit The distance of boundary's point and each selected point (X, Z) coordinate in the frame of reference；

Successively according to (X, Z) coordinate in the frame of reference of each selected point, from altitude data, inquire about the Y of each selected point Coordinate, to obtain position coordinates under the frame of reference for all clutters point.

In described step S3, all clutter points and the computational methods of the relative distance of radar are:

Under the frame of reference, utilize the position coordinates of clutter point and the position coordinates of radar, according to distance between two points meter Calculating formula can the relative distance of all clutter points and radar.

In described step S3, all clutter points with the computational methods of the relative Doppler frequency of radar are:

Under the frame of reference, utilize the position coordinates of clutter point and the position coordinates of radar, be calculated pointing vector；

Pointing vector and radar speed Vector operation is utilized to obtain the angle of each clutter point and radar line and velocity attitude；

Platform aggregate velocity value is utilized to calculate the relative Doppler frequency of do odds and ends wave point and radar.

Take number N on described long distance boundary point and low coverage boundary point line, need to meet following condition:

$\mathrm{\Δ}R=\frac{R_{FN}}{N}\≤\frac{{\mathrm{\ΔR}}_R}{2}$

Wherein, Δ R represents that the adjacent directly distance that takes a little is spaced, R_FNRepresent that long distance boundary point and low coverage boundary point are direct Relative distance, N represents and takes a number, Δ R_RRepresent distance by radar resolution ratio.

The lower main distribution calculation method of principal subsidiary lobe ground and sea clutter of detection and prior art phase after tail is regarded under a kind of radar of the present invention It is determined by the main corresponding relation simplification clutter region being distributed with ground/water area of principal subsidiary lobe clutter than having the advantage that Select, reduce zoning, all clutter unit and the relative distance of radar and relative Doppler frequency in zoning, and reflect It is incident upon distance-Doppler territory, obtains the accurate location of the main distribution of clutter, when can detect target after regarding tail under radar, quickly Calculating principal subsidiary lobe clutter echo-signal, at the main distributing position in distance-Doppler territory, utilizes echo signal miscellaneous with strong secondary lobe for radar Ripple signal relative distance and frequency relation judge or avoid echo signal to fall into or pass through strong secondary lobe clutter district providing core Parameter and important evidence；The present invention calculates real-time, disclosure satisfy that airborne, missile-borne radar to the requirement processing real-time.

Brief description

Fig. 1 is the flow process of the lower main distribution calculation method of principal subsidiary lobe ground and sea clutter of detection after tail under a kind of radar of the present invention Figure；

Fig. 2 is the geometrical relationship block diagram of detection after tail under radar；

Fig. 3 is principal subsidiary lobe ground and sea clutter main distribution result of calculation schematic diagram in the embodiment of the present invention.

Detailed description of the invention

Below in conjunction with accompanying drawing, by describing a preferably specific embodiment in detail, the present invention is further elaborated.

As it is shown in figure 1, the lower main distribution calculation method of principal subsidiary lobe ground and sea clutter of detection after regarding tail under a kind of radar, comprise following Step:

S1, according to regarding under radar detection wave beam all directions gain after tail strong and weak, determine that the main distribution of principal subsidiary lobe ground and sea clutter is right Answer region.

Step S1 specifically comprises:

S1.1, set up the frame of reference and platform coordinate system respectively, as shown in Figure 2；

Wherein, the initial point of the frame of reference is set on ground/sea, and X-axis is north orientation, Y-axis be sky to, Z axis is east orientation, Radar present position is defined as P_R, the coordinate under the frame of reference is (x_R, y_R, z_R), determine radar appearance according to the right-hand rule State, radar attitude is defined as (Ψ, θ, γ), and Ψ represents yaw angle, and θ represents the angle of pitch, and γ represents roll angle；Platform coordinate system is By frame of reference origin translation to radar present position, then it is carried out three rotations according to Ψ, θ, γ attitude angle successively, To platform coordinate system P_RX " Y " Z ", points to angle (α, β) and represents radar antenna wave beam, ground/sea location point and radar at platform Relative position relation in coordinate system, α represents azimuth, and β represents the angle of pitch；

S1.2, according to actual radar directional pattern strength distribution feature, with the sensing angle under platform coordinate system, arrange main Secondary lobe ground and sea clutter long distance boundary point P₁With low coverage boundary point P_NRelative with radar antenna point to, long distance boundary point P₁With low coverage limit Boundary point P_NSensing angle be respectively (α_Far, β_Far) and (α_Near, β_Near), and according to position under the frame of reference for the radar and appearance State calculates long distance boundary point P respectively₁With low coverage boundary point P_NCoordinate under the frame of reference；

Long distance boundary point P₁Coordinate calculation method under the frame of reference comprises:

Under platform coordinate system, long distance boundary point is pointed to angle (α_Far, β_Far) it is calculated sensing unit vector (x_P1, y_P1, z_P1)；

x_P1=cos (β_Far)×cos(α_Far)

y_P1=cos (β_Far)×sin(α_Far)

z_P1=sin (-β_Far)

Changed by Eulerian coordinates, by the sensing unit vector (x under platform coordinate system_P1, y_P1, z_P1) it is transformed into benchmark seat It in mark system, is calculated under the frame of reference sensing unit vector (x_U1, y_U1, z_U1)；

$\left[\begin{array}{c}{x}_{U1}\\ z_{U1}\\ y_{U1}\end{array}\right]=\left[\begin{array}{ccc}\cos \mathrm{\θ}\cos \mathrm{\Ψ}& \cos \mathrm{\γ}\sin \mathrm{\Ψ}+\sin \mathrm{\γ}\sin \mathrm{\θ}\cos \mathrm{\Ψ}& -\sin \mathrm{\γ}\sin \mathrm{\Ψ}+\cos \mathrm{\γ}\sin \mathrm{\θ}\cos \mathrm{\Ψ}\\ \cos \mathrm{\θ}\cos \mathrm{\Ψ}& \cos \mathrm{\γ}\cos \mathrm{\Ψ}-\sin \mathrm{\γ}\sin \mathrm{\θ}\sin \mathrm{\Ψ}& -\sin \mathrm{\γ}\cos \mathrm{\Ψ}-\cos \mathrm{\γ}\sin \mathrm{\θ}\sin \mathrm{\Ψ}\\ -\sin \mathrm{\θ}& \sin \mathrm{\γ}\cos \mathrm{\θ}& \cos \mathrm{\γ}\cos \mathrm{\θ}\end{array}\right]\·\left[\begin{array}{c}{x}_{P1}\\ -y_{P1}\\ z_{P1}\end{array}\right]$

By pointing to unit vector under the frame of reference, platform coordinate is calculated long distance boundary point P₁In the frame of reference Under coordinate (x₁, y₁, z₁)；

$\left[\begin{array}{c}{x}_1\\ y_1\\ z_1\end{array}\right]=\left[\begin{array}{c}{x}_{U1}\\ y_{U1}\\ z_{U1}\end{array}\right]\×\left|\frac{y_R}{y_{U1}}\right|+\left[\begin{array}{c}{x}_R\\ y_R\\ z_R\end{array}\right]$

In like manner, low coverage boundary point P_NCoordinate calculation method under the frame of reference comprises:

Under platform coordinate system, low coverage boundary point is pointed to angle and is calculated sensing unit vector；

Changed by Eulerian coordinates, be transformed into the sensing unit vector under platform coordinate system in the frame of reference, calculate Obtain pointing under the frame of reference unit vector；

By pointing to unit vector under the frame of reference, platform coordinate is calculated low coverage boundary point P_NIn the frame of reference Under coordinate (x_N, y_N, z_N)；

$\left[\begin{array}{c}{x}_N\\ y_N\\ z_N\end{array}\right]=\left[\begin{array}{c}{x}_{UN}\\ y_{UN}\\ z_{UN}\end{array}\right]\×\left|\frac{y_R}{y_{UN}}\right|+\left[\begin{array}{c}{x}_R\\ y_R\\ z_R\end{array}\right]$

S1.3, under the frame of reference, by long distance boundary point P₁With low coverage boundary point P_NLine constitute principal subsidiary lobe ground sea miscellaneous The computation interval of ripple main distribution corresponding region.

S2, in principal subsidiary lobe ground and sea clutter main distribution corresponding region, choose corresponding clutter point, and calculate all clutters point Position coordinates.

Step S2 specifically comprises:

Coordinate (x under the frame of reference, according to long distance boundary point₁, y₁, z₁) and the coordinate (x of low coverage boundary point_N, y_N, z_N) calculate long distance boundary point P₁With low coverage boundary point P_NRelative distance R_FN；

$R_{FN}=\sqrt{{(x_1-x_N)}^2+{(y_1-y_N)}^2+{(z_1-z_N)}^2}$

Under the frame of reference, by the coordinate (x of long distance boundary point₁, y₁, z₁) and the coordinate (x of low coverage boundary point_N, y_N, z_N) calculate long distance boundary point P₁To low coverage boundary point P_NLine and the angle ε of Z axis；

$\mathrm{\ϵ}={\tan }^{-1}\left(\frac{x_1-x_N}{z_1-z_N}\right)$

Set long distance boundary point P₁With low coverage boundary point P_NTake number N on line, calculate each selected point successively relative to closely Away from boundary point P_NDistance R_nNAnd (X, Z) coordinate (x that each selected point is in the frame of reference_n, z_n)；

Wherein, take number N and need to meet condition

Wherein Δ R_RFor distance by radar resolution ratio

R_nN=(N-n+1) × Δ R

x_n=R_nN×sin(ε)+x_N

z_n=R_nN×cos(ε)+z_N

Successively according to (X, Z) coordinate (x in the frame of reference of each selected point_n, z_n), from altitude data, inquire about each choosing Take Y coordinate y a little_n, wherein y_n=H_Gn, H_GnFor ground, selected point place/sea level height, sit at benchmark to obtain all clutters point Position coordinates (x under mark system_n, y_n, z_n), n is by 1 to N value.

S3, the position coordinates according to the position coordinates of radar, the velocity parameter of radar and all clutters point, calculate institute Have clutter point and the relative distance of radar and relative Doppler frequency.

Step S3 specifically comprises:

Under the frame of reference, utilize the position coordinates (x of clutter point_n, y_n, z_n) and the position coordinates (x of radar_R, y_R, z_R), can relative distance R of all clutter points and radar according to distance between two points computing formula_n；

$R_n=\sqrt{{(x_n-x_R)}^2+{(y_n-y_R)}^2+{(z_n-z_R)}^2}$

Under the frame of reference, utilize the position coordinates (x of clutter point_n, y_n, z_n) and the position coordinates (x of radar_R, y_R, z_R), it is calculated pointing vector

Utilize pointing vectorWith radar speed vectorIt is calculated each clutter point and radar line Included angle with velocity attitude_n；

Radar aggregate velocity value is utilized to be calculated relative Doppler frequency F of clutter point and radar_n；

$F_n=\frac{2\left|\stackrel{\→}{V_R}\right|}{\mathrm{\λ}}cos\left({\mathrm{\φ}}_n\right)$

Wherein, λ is radar emission signal wavelength, and radar speed vector is obtained by inertial device, airborne radar or missile-borne The velocity of the i.e. corresponding platform of radar.

The pulse recurrence frequency parameter of S4, the maximum unam combining radar emission signal and radar emission signal, Calculate apparent range and the apparent Doppler frequency of all clutters point.

Apparent range Δ R in step S4_nWith apparent Doppler frequency Δ F_nComputing formula be respectively as follows:

ΔR_n=mod (R_n, R_max)

Wherein, R_maxFor launching signal maximum unam；

ΔF_n=mod (F_n, PRF)

Wherein, PRF is for launching the pulse recurrence frequency of signal.

S5, the apparent range quantifying all clutters point and apparent Doppler frequency, and by the quantized distance of all clutter points Map to distance-Doppler territory (Δ QR with quantifying Doppler frequency_n, Δ QF_n), (n=1,2 ... N), obtain principal subsidiary lobe ground sea miscellaneous The accurate location of the main distribution of ripple.

In step S5, quantify the apparent range Δ R of all clutters point_nWith apparent Doppler frequency Δ F_n, obtain quantized distance ΔQR_nWith quantization Doppler frequency Δ QF_n, wherein

${\mathrm{\ΔQR}}_n={\mathrm{\ΔR}}_R\·ceil\left(\frac{{\mathrm{\ΔR}}_n}{{\mathrm{\ΔR}}_R}\right)$

Wherein, Δ_RR is distance by radar resolution ratio；

${\mathrm{\ΔQF}}_n={\mathrm{\ΔF}}_R\·ceil\left(\frac{{\mathrm{\ΔF}}_n}{{\mathrm{\ΔF}}_R}\right)$

Wherein, Δ F_RRadar frequency resolution ratio.

As it is shown on figure 3, give radar fix (61310,14958,52736), radar attitude (-38 ,-22,0), speed Vector (709 ,-371,564), long distance boundary point points to (-0.5 ,-10), and low coverage boundary point points to (0 ,-80), and radar emission is believed Number pulse recurrence frequency 41kHz under the conditions of, principal subsidiary lobe ground and sea clutter main distribution result of calculation figure.

Although present disclosure has been made to be discussed in detail by above preferred embodiment, but it should be appreciated that above-mentioned Description is not considered as limitation of the present invention.After those skilled in the art have read foregoing, for the present invention's Multiple modifications and replacement all will be apparent from.Therefore, protection scope of the present invention should be limited to the appended claims.

Claims (10)

1. regard the lower main distribution calculation method of principal subsidiary lobe ground and sea clutter of detection after tail under a radar, it is characterised in that comprise following Step:

S1, according to regarding under radar detection wave beam all directions gain after tail strong and weak, determine the corresponding district of the main distribution of principal subsidiary lobe ground and sea clutter Territory；

S2, in principal subsidiary lobe ground and sea clutter main distribution corresponding region, choose corresponding clutter point, and calculate the position of all clutters point Put coordinate；

S3, the position coordinates according to the position coordinates of radar, the velocity parameter of radar and all clutters point, calculate all miscellaneous Wave point and the relative distance of radar and relative Doppler frequency；

The pulse recurrence frequency parameter of S4, the maximum unam combining radar emission signal and radar emission signal, calculates The apparent range of all clutter points and apparent Doppler frequency；

S5, the apparent range quantifying all clutters point and apparent Doppler frequency, and by the quantized distance of all clutter points and amount Change Doppler frequency and map to distance-Doppler territory, obtain the accurate location of the main distribution of principal subsidiary lobe ground and sea clutter.

2. under radar as claimed in claim 1, regard the lower main distribution calculation method of principal subsidiary lobe ground and sea clutter of detection after tail, its feature Being, described step S1 comprises:

S1.1, set up the frame of reference and platform coordinate system respectively；

S1.2, according to actual radar directional pattern strength distribution feature, with the sensing angle under platform coordinate system, principal subsidiary lobe is set Ground and sea clutter long distance boundary point is relative with radar antenna with low coverage boundary point to be pointed to, and according to position under the frame of reference for the radar Put and calculate long distance boundary point and coordinate under the frame of reference for the low coverage boundary point respectively with attitude；

S1.3, under the frame of reference, be made up of principal subsidiary lobe ground and sea clutter master the line of long distance boundary point and low coverage boundary point and divide The computation interval of cloth corresponding region.

3. under radar as claimed in claim 2, regard the lower main distribution calculation method of principal subsidiary lobe ground and sea clutter of detection after tail, its feature Being, in described step S1.1, the initial point of the frame of reference is set on ground/sea, and X-axis is north orientation, and Y-axis is that sky is to Z Axle is east orientation, and radar present position is defined as P_R, the coordinate under the frame of reference is (x_R, y_R, z_R), true according to the right-hand rule Determining radar attitude, radar attitude is defined as (Ψ, θ, γ), and Ψ represents yaw angle, and θ represents the angle of pitch, and γ represents roll angle.

4. under radar as claimed in claim 3, regard the lower main distribution calculation method of principal subsidiary lobe ground and sea clutter of detection after tail, its feature Being, the described platform coordinate system in step S1.1 is to radar present position by frame of reference origin translation, then by it Carry out three times according to Ψ, θ, γ attitude angle successively to rotate, obtain platform coordinate system P_RX " Y " Z ", points to angle (α, β) and represents radar Antenna beam, ground/sea location point and relative position relation in platform coordinate system for the radar, α represents azimuth, and β represents The angle of pitch.

5. under radar as claimed in claim 4, regard the lower main distribution calculation method of principal subsidiary lobe ground and sea clutter of detection after tail, its feature Being, in described step S1.2, Coordinate calculation method under the frame of reference for the long distance boundary point comprises:

Under platform coordinate system, long distance boundary point is pointed to angle and is calculated sensing unit vector；

Changed by Eulerian coordinates, be transformed into the sensing unit vector under platform coordinate system in the frame of reference, be calculated Unit vector is pointed under the frame of reference；

By pointing to unit vector under the frame of reference, platform coordinate is calculated seat under the frame of reference for the long distance boundary point Mark.

6. under radar as claimed in claim 5, regard the lower main distribution calculation method of principal subsidiary lobe ground and sea clutter of detection after tail, its feature Being, in described step S1.2, Coordinate calculation method under the frame of reference for the low coverage boundary point comprises:

Under platform coordinate system, low coverage boundary point is pointed to angle and is calculated sensing unit vector；

Changed by Eulerian coordinates, be transformed into the sensing unit vector under platform coordinate system in the frame of reference, be calculated Unit vector is pointed under the frame of reference；

By pointing to unit vector under the frame of reference, platform coordinate is calculated seat under the frame of reference for the low coverage boundary point Mark.

7. under radar as claimed in claim 6, regard the lower main distribution calculation method of principal subsidiary lobe ground and sea clutter of detection after tail, its feature Being, described step S2 comprises:

Under the frame of reference, coordinate and the coordinate of low coverage boundary point according to long distance boundary point calculate long distance boundary point and low coverage The relative distance of boundary point；

Under the frame of reference, calculate long distance boundary point to low coverage by the coordinate of long distance boundary point and the coordinate of low coverage boundary point Boundary point line and the angle of Z axis；

Set and take a number on long distance boundary point and low coverage boundary point line, calculate each selected point successively relative to low coverage boundary point Distance and each selected point (X, Z) coordinate in the frame of reference；

Successively according to (X, Z) coordinate in the frame of reference of each selected point, the Y inquiring about each selected point from altitude data sits Mark, to obtain position coordinates under the frame of reference for all clutters point.

8. under radar as claimed in claim 7, regard the lower main distribution calculation method of principal subsidiary lobe ground and sea clutter of detection after tail, its feature Being, in described step S3, all clutter points and the computational methods of the relative distance of radar are:

Under the frame of reference, utilize the position coordinates of clutter point and the position coordinates of radar, calculate public affairs according to distance between two points Shi Ke get all clutters point and the relative distance of radar.

9. under radar as claimed in claim 7, regard the lower main distribution calculation method of principal subsidiary lobe ground and sea clutter of detection after tail, its feature Being, in described step S3, all clutter points with the computational methods of the relative Doppler frequency of radar are:

Under the frame of reference, utilize the position coordinates of clutter point and the position coordinates of radar, be calculated pointing vector；

Pointing vector and radar speed Vector operation is utilized to obtain the angle of each clutter point and radar line and velocity attitude；

Platform aggregate velocity value is utilized to calculate the relative Doppler frequency of do odds and ends wave point and radar.

10. under radar as claimed in claim 7, regard the lower main distribution calculation method of principal subsidiary lobe ground and sea clutter of detection after tail, its feature It is, described long distance boundary point and low coverage boundary point line takes number N, need to meet following condition:

$\mathrm{\Δ}R=\frac{R_{FN}}{N}\≤\frac{{\mathrm{\ΔR}}_R}{2}$

Wherein, Δ R represents that the adjacent directly distance that takes a little is spaced, R_FNRepresent that long distance boundary point is directly relative with low coverage boundary point Distance, N represents and takes a number, Δ R_RRepresent distance by radar resolution ratio.