CN112415478A - Data processing method of narrow-beam radar clutter in staring state - Google Patents

Abstract

The invention discloses a data processing method of narrow-beam radar clutter in a staring state, which comprises the following steps: step 1, according to the fixation point

GPS position of, calculating

At time, carrying machine and point

Relative pitch of slope

And radar beam centerline and point

Floor wiping corner

(ii) a Step 2, calculating the corresponding ground wiping angle of the upper edge and the lower edge of the main beam irradiation area; step 3, calculating the corresponding slope distances of the two ground wiping angles

And

(ii) a Step 4, calculating the gate number of the corresponding distance of the upper edge and the lower edge of the radar main beam; step 5, according to the calculation result, the range of the range gate of the clutter in the main beam irradiation area in the data is

And intercepting the corresponding clutter data at each moment so as to obtain the main beam clutter. The method disclosed by the invention can automatically calculate the irradiation area of the main beam of the radar and select the clutter of the main beam according to the irradiation area, thereby greatly improving the convenience and accuracy of data processing.

Description

Data processing method of narrow-beam radar clutter in staring state

Technical Field

The invention belongs to the field of airborne radar clutter characteristic analysis, and particularly relates to a clutter data processing method for automatically selecting a main beam irradiation range based on information such as an airborne flight track, radar parameters and the like in the field.

Background

Most of existing airborne radar clutter data processing methods are developed for modes of wide beams and fixed downward depression angles, and a common method is to determine the main beam irradiation range of a radar according to the downward depression angle and select clutter area data for processing according to a noise-to-noise ratio. Because the existing airborne radar has various working modes and radar parameters, the existing airborne data processing method is difficult to cover all the modes and parameters, particularly for clutter data of the narrow-beam radar in a staring state, the factors such as flight path, relative position of a fixation point, continuous change of an irradiation area and the like are involved, and the data processing difficulty is relatively high.

Disclosure of Invention

The invention aims to provide a data processing method of narrow-beam radar clutter in a staring state.

The invention adopts the following technical scheme:

in a method of processing data for narrow beam radar clutter in a staring state, the improvement comprising the steps of:

step 1, calculating the relative slope distance R between the aircraft and a point O at t time according to the inertial navigation track of the aircraft at each time and the GPS position of a fixation point O_tAnd ground angle theta of the center line of the radar beam and point O_t；

Step 2, using the ground wiping angle theta_tAnd radar pitch beamwidth

Calculating the corresponding wipe of the upper and lower edges of the main beam irradiation regionGround corner

And

step 3, according to the ground wiping angle theta_1tAnd theta_2tCalculating the slope distances R corresponding to the two ground-wiping angles respectively according to the value of (A) and the height H of the carrier_1tAnd R_2t；

Step 4, combining the length r of the range gate unit_eCalculating the gate number of the corresponding distance between the upper edge and the lower edge of the radar main beam:

N_1t＝(R_1t-R_wave)/r_e；N_2t＝(R_2t-R_wave)/r_e (1)

wherein R is_waveIs the front edge amount of the wave gate;

step 5, according to the calculation result, the range of the range gate of the clutter of the main beam irradiation area in the data is N_1t～N_2tAnd intercepting the corresponding clutter data at each moment so as to obtain the main beam clutter.

The invention has the beneficial effects that:

the method disclosed by the invention can automatically calculate the irradiation area of the main beam of the radar and select the clutter of the main beam according to the irradiation area, thereby greatly improving the convenience and the accuracy of data processing, avoiding the mixed entrainment noise in the clutter data, improving the accuracy of clutter characteristic analysis, and compared with the method for selecting the clutter by contrasting the two-dimensional map of echo data, the method has very high convenience.

Drawings

FIG. 1 is a schematic view of an airborne radar gaze test;

FIG. 2 is a two-dimensional map of airborne radar returns;

FIG. 3 shows the pitch R_tA change diagram of relative time (frame);

FIG. 4 is a floor wiping angle θ_tA change diagram of relative time (frame);

FIG. 5 is a floor wiping angle θ_1tAnd theta_2tRelative time of day(frame) schematic representation of the changes;

FIG. 6 shows the pitch R_1tAnd R_2tA change diagram of relative time (frame);

FIG. 7 shows a distance gate N_1tAnd N_2tA change diagram of relative time (frame);

FIG. 8 is a schematic diagram of a clutter data selection range.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the embodiment 1, according to the flight inertial navigation data of the aircraft and the radar parameters, as shown in fig. 1, the gaze point is O, the radar beam is kept to irradiate the point O during the flight of the aircraft, and parameters such as the ground clearance angle θ, the azimuth angle Φ, the radar and gaze point slope distance R, and the irradiation area a are changed along with the flight of the aircraft. Assume a radar pitch beamwidth of

Distance gate unit length r_eBecause the radar beam is narrow, and the range of the irradiation area is changed due to the flying of the airplane in the staring state, the range of the range gate covered by the clutter echo is changed, and therefore the range gate range selection is required to be corrected at any moment.

Taking a certain radar airborne flight test as an example, the radar beam width is 3 degrees, and the distance unit length is 0.78 m. The flight height of the aircraft is about 1100m, the elevation height of the fixation point position is 60m, 7000 moments of inertial navigation information is stored in radar inertial navigation data, and each moment corresponds to the flight path position of the aircraft. As is apparent from fig. 2, the range of clutter is gradually reduced as the carrier is closer to the gaze point location. According to the information, calculating the range of the range gate corresponding to the clutter of the main beam at each moment, and specifically comprising the following steps:

step 1, according to inertial navigation track and fixation point O of each moment of the aircraftGPS position, calculating the relative slope distance R between the carrier and the point O at t time_tAnd ground angle theta of the center line of the radar beam and point O_t(ii) a See fig. 3 and 4.

Step 2, using the ground wiping angle theta_tAnd radar pitch beamwidth

Calculating the corresponding ground wiping angle of the upper and lower edges of the main beam irradiation region

And

see fig. 5.

Step 3, according to the ground wiping angle theta_1tAnd theta_2tCalculating the slope distances R corresponding to the two ground-wiping angles respectively according to the value of (A) and the height H of the carrier_1tAnd R_2t(ii) a See fig. 6.

Step 4, combining the length r of the range gate unit_eCalculating the gate number of the corresponding distance between the upper edge and the lower edge of the radar main beam:

N_1t＝(R_1t-R_wave)/r_e；N_2t＝(R_2t-R_wave)/r_e (1)

wherein R is_waveThe amount of the front edge of the wave gate needs to be subtracted when calculating the range gate. From this, the corresponding range gate number of the main beam of the radar is obtained, see FIG. 7, where N_1tRanging from 1 to 2000 frames in time to 1 and then increasing gradually, N_2tGradually decrease;

step 5, according to the calculation result, the range of the range gate of the clutter of the main beam irradiation area in the data is N_1t～N_2tAnd intercepting the corresponding clutter data at each moment so as to obtain the main beam clutter. As can be seen from FIG. 8, the selected range gate range between the black line and the white line is better matched with the radar clutter highlight region, which indicates that the data processing method is effective.

The embodiment overcomes the defect that the main beam clutter data range is difficult to determine for the narrow-beam radar in the staring state in the prior art, provides the method for automatically intercepting the clutter range based on the aircraft flight inertial navigation data and the radar parameters, and can be generally used for radar clutter data preprocessing in the mode.

Claims (1)

1. A data processing method of narrow-beam radar clutter in a staring state is characterized by comprising the following steps:

step 1, calculating the relative slope distance R between the aircraft and a point O at t time according to the inertial navigation track of the aircraft at each time and the GPS position of a fixation point O_tAnd ground angle theta of the center line of the radar beam and point O_t；

Step 2, using the ground wiping angle theta_tAnd radar pitch beamwidth

Calculating the corresponding ground wiping angle of the upper and lower edges of the main beam irradiation region

And

step 3, according to the ground wiping angle theta_1tAnd theta_2tCalculating the slope distances R corresponding to the two ground-wiping angles respectively according to the value of (A) and the height H of the carrier_1tAnd R_2t；

Step 4, combining the length r of the range gate unit_eCalculating the gate number of the corresponding distance between the upper edge and the lower edge of the radar main beam:

N_1t＝(R_1t-R_wave)/r_e；N_2t＝(R_2t-R_wave)/r_e (1)

wherein R is_waveIs the front edge amount of the wave gate;

step 5, according to the calculation result, the range of the range gate of the clutter of the main beam irradiation area in the data is N_1t～N_2tAnd intercepting the corresponding clutter data at each moment so as to obtain the main beam clutter.

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