CN116482643A - Radar blind area calculation display method based on terrain analysis - Google Patents

Abstract

The invention discloses a radar blind area calculation display method based on terrain analysis, and relates to the field of military equipment capacity analysis and map display of a command automation system. Based on the visual analysis, firstly, a shielding point and a tangent line segment of the radar and the terrain in a scanning direction are calculated through binary search, then, intersection points are directly calculated by using a tangent line segment equation of the scanning direction and a geodetic ellipsoid equation of different heights, the maximum detection range of the radar in the height is obtained by connecting intersection points of tangent line segments of all the scanning directions in ellipsoids of the same height, and the shielding line and the contour lines of different heights are drawn and displayed by using different colors and line widths. The method is simple, efficient and reliable, is suitable for various geographic computing platforms, is concise and visual to express on a two-dimensional map, has the capability of adapting to parallel computing platforms, and has the characteristics of adjustable computing precision as required and adaptation to various radar parameter types.

Description

Radar blind area calculation display method based on terrain analysis

Technical Field

The invention relates to a radar blind area calculation display method based on terrain analysis in the field of military equipment capacity analysis and plot display of a command automation system, which is particularly suitable for displaying and applying detection capacity analysis and analysis results based on terrain to typical air defense radar equipment in the command automation system.

Background

The remote air defense warning radar, the short-range field air defense radar and the like are main threats facing the army aviation soldier equipment, and the detection capability analysis is an indispensable important capability in an army aviation soldier command automation system for avoiding the threat or carrying out early warning on the threat in time. Due to the effects of the earth curvature, the terrain shielding and other factors, the radar detection has the terrain shielding blind area, and the rapid analysis and the comprehensive and visual expression of the terrain shielding blind area become a key technology. In the prior art, the calculation method for the radar terrain shading blind area mainly carries out shading calculation on the connecting line of the target point and the radar deployment position and all terrain surfaces where the connecting line is located to obtain the minimum height of the target point, and takes the minimum height of the target point as the blind area clearance height of the target point. However, the calculation method is complicated in steps, long in analysis time and low in efficiency, and the detection blind area cannot be intuitively expressed and displayed on the two-dimensional map, so that support for auxiliary analysis and result representation capability of the combat command is insufficient.

Disclosure of Invention

The invention aims to solve the technical problem of avoiding the defects in the background technology and providing a radar blind area calculation display method based on topographic analysis.

The method is simple, efficient and reliable, is suitable for various geographic computing platforms, is concise and visual to express on a two-dimensional map, has the capability of adapting to parallel computing platforms, and has the characteristics of adjustable computing precision as required and adaptation to various radar parameter types.

The invention aims at realizing the following steps:

a radar blind area calculation display method based on terrain analysis specifically comprises the following steps:

step 1, calculating a tangent line between a ray taking a radar coordinate O as a starting point and alpha as a scanning azimuth and a terrain by using a binary search method based on the vision calculation, recording a tangent point Q (alpha), and simultaneously calculating a radar maximum action distance point on the ray and recording the radar maximum action distance point as F (alpha);

step 2, judging whether the length OF the line segment OF (alpha) is larger than the length OF the line segment OQ (alpha), if so, calculating the intersection points OF the line segment Q (alpha) F (alpha) and the high-earth ellipsoids OF 100 meters, 200 meters, 400 meters, 800 meters, 1600 meters, 2400 meters and 3600 meters respectively, and if the intersection points exist, recording the intersection points as H (alpha, 100), H (alpha, 200), H (alpha, 400), H (alpha, 800), H (alpha, 1600), H (alpha, 2400) and H (alpha, 3600) respectively;

step 3, taking delta alpha as a step, and repeating the steps 1 to 2 within the range of radar scanning azimuth alpha min-alpha max;

step 4, judging whether the tangential point OF each calculated azimuth alpha and the adjacent azimuth alpha plus delta alpha meets OQ (alpha) < OF (alpha) and OQ (alpha plus delta alpha) < OF (alpha plus delta alpha), if so, connecting Q (alpha) and Q (alpha plus delta alpha) by using a thickened black line segment, and if not, connecting;

step 5, connecting the maximum action distance points F (alpha) and F (alpha+delta alpha) of each calculated azimuth alpha and the adjacent azimuth alpha+delta alpha by using a thickened red line segment;

and 6, setting different colors for heights of 100 meters, 200 meters, 400 meters, 800 meters, 1600 meters, 2400 meters and 3600 meters, judging whether intersection points H (alpha, H) and H (alpha+delta alpha, H) with the same height exist simultaneously between each calculated azimuth alpha and the adjacent azimuth alpha+delta alpha, and connecting the intersection points H (alpha, H) with thin lines with the corresponding colors of the heights, otherwise, connecting the H (alpha, H) to a tangent point Q (alpha+delta alpha) if only the H (alpha, H) exists.

Further, the specific process of the step 2 is as follows:

step 201, converting the geodetic coordinates of the points Q (α) and F (α) into a geodetic coordinate system (xq, yq, zq), (xf, yf, zf), calculating the straight line distance of (xq, yq, zq) (xf, yf, zf), if the straight line distance is less than 1 meter, returning to no intersection point, otherwise, continuing the subsequent calculation;

step 202, setting the height of the contour line as h, returning to have no intersection point if the height of Q (alpha) is larger than h, otherwise setting the major axis of the geodetic ellipsoid parameter as a0 and the minor axis as b0, and calculating a new ellipsoid parameter a2= (a0+h)/(2), b2= (b0+h)/(2);

and 203, substituting a parameter equation of a point on a line segment formed by Q (alpha) and F (alpha) into a new ellipsoid parameter, calculating whether an intersection point is formed, returning if no intersection point exists, returning the intersection point if 1 intersection point exists, and returning the intersection point closest to the maximum distance point F (alpha) if 2 intersection points exist.

Compared with the prior art, the invention has the advantages that:

1. the invention uses a binary search method to calculate the tangential line of the scanning azimuth and the terrain based on the visual calculation, so that the invention can be suitable for various geographic calculation platforms, and the binary search depth can be set according to the pitch precision requirement.

2. The method uses the tangential equation and the geodetic ellipsoid equation with different heights to directly calculate the intersection point based on the detection range of the radar, has high calculation precision, and can adapt to the radars with different heights and detection ranges according to different process parameters.

3. The invention adopts proper height parameters, and uses different colors and lines to plot and display the shielding line, the contour line and the maximum detection range line, thereby greatly supporting the comprehensiveness and intuitiveness of the drawing result of the radar detection capability on the two-dimensional map.

4. The calculation result of the invention is easy to store, and can be conveniently applied to subsequent applications such as route planning, threat analysis and the like.

Drawings

Fig. 1 is a schematic diagram of the present invention for realizing the drawing of radar detection capability using a radar blind area calculation display method based on terrain analysis.

Detailed Description

The following describes in further detail the embodiments of the present invention with reference to the drawings and examples.

Referring to fig. 1, the present invention calculates the tangential point of the radar and the terrain at each azimuth based on the view calculation and the binary search, forms a line segment on the scanning line with the tangential point as the start point and the maximum detection range point as the end point, calculates the intersection point of the line segment and the ellipsoidal surface of different heights, uses the black widening line to connect the tangential point of each azimuth as the shielding line, uses the red widening line to connect the maximum detection range point of each azimuth as the maximum detection range line, uses the different colors to connect the same height and the same height as each azimuth to form the different height detection range line, and realizes the final radar detection blind area result display. The invention calculates the detection range lines at different height intervals, so that the calculation results are uniformly displayed and distributed, and a user quickly forms concise and visual knowledge on the radar detection blind area.

A radar blind area calculation display method based on terrain analysis is characterized by comprising the following steps:

(1) based on the vision calculation, calculating a tangent line between a ray taking a radar coordinate O as a starting point and taking alpha as a scanning azimuth and a terrain by using a binary search method, recording a tangent point Q (alpha), and simultaneously calculating a radar maximum acting distance point on the ray and recording the radar maximum acting distance point as F (alpha);

in the embodiment, a minimum pitch angle alpha_min and a maximum pitch angle alpha_max are set, O is taken as an origin, the azimuth is alpha, the pitch angle alpha_c= (alpha_min+alpha_max)/2, a maximum acting distance point Fa is calculated by a maximum detection distance rmax, whether a line segment OFa is in a clear view or not is judged, if so, alpha_max=alpha_c is set, otherwise, alpha_min=alpha_c is set, the pitch angle alpha_c= (alpha_min+alpha_max)/2 and Fa are recalculated, and the calculation is continued for 20 times, wherein a shielding point Q (alpha) and a maximum total acting distance point F (alpha) are calculated according to alpha_min.

(2) Judging whether the length OF the line segment OF (alpha) is larger than the length OF the line segment OQ (alpha), if so, calculating the intersection points OF the line segment Q (alpha) F (alpha) and the altitude geodetic ellipsoids OF 100 meters, 200 meters, 400 meters, 800 meters, 1600 meters, 2400 meters and 3600 meters respectively, and if the intersection points exist, recording the intersection points as H (alpha, 100), H (alpha, 200), H (alpha, 400), H (alpha, 800), H (alpha, 1600), H (alpha, 2400) and H (alpha, 3600) respectively;

(3) repeating the steps (1) and (2) within the range of radar scanning azimuth alpha min-alpha max by taking delta alpha as a step;

embodiments αmin and αmax are the minimum scan azimuth and the maximum scan azimuth of the radar, typically set radar performance parameters, αmin=0 if the radar is omni-directional, αmax= 359.9, and the calculation is started from α=αmin, each time the azimuth Δα is increased, i.e., α=α+Δα, if α < αmax, the calculation is continued, otherwise the calculation is stopped.

(4) Drawing a shielding line: judging whether the tangential point OF each calculated azimuth alpha and the adjacent azimuth alpha plus delta alpha meets OQ (alpha) < OF (alpha) and OQ (alpha plus delta alpha) < OF (alpha plus delta alpha), if so, connecting Q (alpha) and Q (alpha plus delta alpha) by using a thickened black line segment, and if not, connecting;

in the embodiment, the radar position O is represented by (xo, yo, zo), the shielding point OF the azimuth alpha is represented by Q (α), the geocentric coordinate is represented by (xq, yq, zq), the maximum action range point is represented by F (α), the geocentric coordinate is represented by (xf, yf, zf), the shielding point OF the adjacent azimuth alpha is represented by Q (α+Δα), the geocentric coordinate is represented by (xq 1, yq1, zq 1), the maximum action range point is represented by F (α+Δα), the geocentric coordinate system is represented by (xf 1, yf1, zf 1), and the judgment is made that (xq-xo) < 2+ (zq-zo) < 2+ (yf-zo) < 2+ (xf-zo) < α), Q (α), and the judgment is made that (xq-xo) < 2+ (xq-xq+1-xq) < Δf-2+ (xq-xq 2) < α -xq+1).

(5) Drawing a maximum effect range line: connecting the maximum action distance points F (alpha) and F (alpha+delta alpha) of each calculated azimuth alpha and the adjacent azimuth alpha+delta alpha by a bolded red line segment;

(6) drawing contour lines: different colors are set for heights of 100 meters, 200 meters, 400 meters, 800 meters, 1600 meters, 2400 meters and 3600 meters, whether intersection points H (alpha, H) and H (alpha+ [ delta ] alpha, H) with the same height exist simultaneously in each calculated azimuth alpha and the adjacent azimuth alpha+ [ delta ] alpha are judged, the intersection points H (alpha, H) and H (alpha+ [ delta ] alpha, H) are connected by thin lines with the corresponding colors, otherwise, if only H (alpha, H) exists, the intersection points H (alpha, H) are connected to a tangent point Q (alpha+ [ delta ] alpha).

In the embodiment, the line width is 2 for the 100 m height, the color is red, the line width is 1 for the 200 m height, the color is light red, the line width is 2 for the 400 m height, the color is green, the line width is 1 for the 800 m height, the color is light green, the line width is 2 for the 1600 m height, the color is blue, the line width is 1 for the 2400 m height, the color is light blue, the line width is 2 for the 3600 m height, and the color is cyan.

Wherein, the step (2) specifically comprises the following steps:

(201) Converting the geodetic coordinates of the points Q (alpha) and F (alpha) into geodetic coordinates (xq, yq, zq), (xf, yf, zf), calculating the linear distance of (xq, yq, zq) (xf, yf, zf), returning to no intersection point if the linear distance is less than 1 meter, otherwise, continuing the subsequent calculation;

embodiments calculate the distance Lqf = ((xf-xq)/(2+ (yf-yq)/(2+ (zf-zq)/(2)).

(202) Setting the height of a contour line as h, returning to have no intersection point if the height of Q (alpha) is larger than h, otherwise setting the major axis of a geodetic ellipsoid parameter as a0 and the minor axis as b0, and calculating a new ellipsoid parameter a2= (a0+h)/(2), b2= (b0+h)/(2);

in the embodiment, the height of the contour line is h, the geodetic coordinates (Bq, lq, hq) of Q (alpha) are calculated, if Hq > h, the height of the shielding point is larger than the height of the contour line, and an intersection point cannot be formed at the moment, so that no intersection point is returned, otherwise, the intersection point is calculated according to a new ellipsoid parameter, the ellipsoid parameter of a WGS84 coordinate system is adopted, namely, the major axis a0= 6378137.0, the minor axis b0= 6356752.3142, and the length of the major axis and the minor axis is increased by h to serve as the new major axis and the new minor axis.

(203) Substituting a parameter equation of a point on a line segment formed by Q (alpha) and F (alpha) into a new ellipsoid parameter, calculating whether an intersection point is formed, returning if no intersection point exists, returning the intersection point if 1 intersection point exists, and returning the intersection point closest to the maximum distance point F (alpha) if 2 intersection points exist.

The example calculates the vector (Δx, Δy, Δz) = (xf, yf, zf) - (xq, zq), calculates the parameter a= (Δx+Δy, Δy)/a2+Δz, Δz/b2, b=2 (xq+yq, Δy)/a2+2, zq/b2, c= (xq+xq+yq, yq)/a2+zq, zq/b2-1.0, flag=b, b-4, a c, if flag <0, returns the non-intersection point, otherwise calculates the parameter it 1= (-b+flag, 0.5)/(2*a), 2= (-b-g, 0.5)/(2*a), if both values are exchanged. Judging whether it1 is in the range of 0 to 1.0, if so, calculating an intersection point I1=Q (alpha) + (F (alpha) -Q (alpha)). It1, and similarly, calculating an intersection point I2, if the intersection point I2 exists, returning to the intersection point I2, otherwise, returning to the intersection point I1 and ending.

And (3) completing the radar blind area calculation and display method based on the terrain analysis.

Claims (2)

1. A radar blind area calculation display method based on terrain analysis is characterized by comprising the following steps:

step 1, calculating a tangent line between a ray taking a radar coordinate O as a starting point and alpha as a scanning azimuth and a terrain by using a binary search method based on the vision calculation, recording a tangent point Q (alpha), and simultaneously calculating a radar maximum action distance point on the ray and recording the radar maximum action distance point as F (alpha);

step 2, judging whether the length OF the line segment OF (alpha) is larger than the length OF the line segment OQ (alpha), if so, calculating the intersection points OF the line segment Q (alpha) F (alpha) and the high-earth ellipsoids OF 100 meters, 200 meters, 400 meters, 800 meters, 1600 meters, 2400 meters and 3600 meters respectively, and if the intersection points exist, recording the intersection points as H (alpha, 100), H (alpha, 200), H (alpha, 400), H (alpha, 800), H (alpha, 1600), H (alpha, 2400) and H (alpha, 3600) respectively;

step 3, taking delta alpha as a step, and repeating the steps 1 to 2 within the range of radar scanning azimuth alpha min-alpha max;

step 4, judging whether the tangential point OF each calculated azimuth alpha and the adjacent azimuth alpha plus delta alpha meets OQ (alpha) < OF (alpha) and OQ (alpha plus delta alpha) < OF (alpha plus delta alpha), if so, connecting Q (alpha) and Q (alpha plus delta alpha) by using a thickened black line segment, and if not, connecting;

step 5, connecting the maximum action distance points F (alpha) and F (alpha+delta alpha) of each calculated azimuth alpha and the adjacent azimuth alpha+delta alpha by using a thickened red line segment;

and 6, setting different colors for heights of 100 meters, 200 meters, 400 meters, 800 meters, 1600 meters, 2400 meters and 3600 meters, judging whether intersection points H (alpha, H) and H (alpha+delta alpha, H) with the same height exist simultaneously between each calculated azimuth alpha and the adjacent azimuth alpha+delta alpha, and connecting the intersection points H (alpha, H) with thin lines with the corresponding colors of the heights, otherwise, connecting the H (alpha, H) to a tangent point Q (alpha+delta alpha) if only the H (alpha, H) exists.

2. The radar blind area calculation and display method based on terrain analysis according to claim 1, wherein the specific process of the step 2 is as follows:

step 201, converting the geodetic coordinates of the points Q (α) and F (α) into a geodetic coordinate system (xq, yq, zq), (xf, yf, zf), calculating the straight line distance of (xq, yq, zq) (xf, yf, zf), if the straight line distance is less than 1 meter, returning to no intersection point, otherwise, continuing the subsequent calculation;

step 202, setting the height of the contour line as h, returning to have no intersection point if the height of Q (alpha) is larger than h, otherwise setting the major axis of the geodetic ellipsoid parameter as a0 and the minor axis as b0, and calculating a new ellipsoid parameter a2= (a0+h)/(2), b2= (b0+h)/(2);

and 203, substituting a parameter equation of a point on a line segment formed by Q (alpha) and F (alpha) into a new ellipsoid parameter, calculating whether an intersection point is formed, returning if no intersection point exists, returning the intersection point if 1 intersection point exists, and returning the intersection point closest to the maximum distance point F (alpha) if 2 intersection points exist.