Navigation precision assessment data processing method

Abstract

The invention provides a navigation precision assessment data processing method, which comprises the following steps of: 1, determining a transmitting point and a navigation point according to track parameters, and converting from a Chinese geodetic coordinate system to a geocentric large earth coordinate system; 2, according to the basic theorem of a spherical triangle, solving a large circle route between a launching point and a navigation point; 3, according to the sine and cosine theorem of the spherical triangle, the deviation distance between the actual track of the target and the large circle route is determined in the spherical right triangle, and the deviation distance represents the actual navigation precision; and performing navigation precision assessment according to the deviation distance. According to the method, a target navigation precision problem is converted into a target actual track and large circle route distance problem through coordinate conversion by utilizing a large circle route method and a spherical triangle theorem, so that a problem processing thought is simplified, the operation is simple and clear, the result precision is high, and data processing personnel can conveniently carry out processing work.

Description

Technical Field

[0001] This invention relates to the field of navigation accuracy assessment technology, and specifically to a navigation accuracy assessment data processing method. Background Technology

[0002] Currently, with technological updates and developments, the requirements for flight target evaluation and assessment are becoming increasingly detailed, and navigation accuracy is a crucial assessment component. Navigation accuracy, given an initial launch angle, involves calculating the distance between the target's trajectory position and the theoretical great circle route from the launch point to the navigation point using the target's own trajectory planning. The assessment is considered successful when the target's navigation accuracy is below a certain threshold and maintains at least a certain flight distance. For external measurement data processing, this assessment requirement differs significantly from conventional trajectory calculation problems, and there are no mature algorithmic models to solve this type of problem. New approaches and methods must be explored through data processing techniques. Currently, there are no effective solutions for this issue in China. Summary of the Invention

[0003] In view of this, the present invention provides a navigation accuracy assessment data processing method, which can improve the accuracy of navigation accuracy assessment.

[0004] To solve the above-mentioned technical problems, the present invention is implemented as follows.

[0005] A navigation accuracy assessment data processing method transforms the target navigation accuracy problem into a problem involving the target's actual trajectory and the distance to a great circle route. The method includes: Step 1: Based on the trajectory parameters, determine the launch point and navigation point, and convert from the Chinese geodetic coordinate system to the geocentric coordinate system; Step 2: Solve for the great circle route between the launch point and the navigation point using the fundamental theorem of spherical triangles; Step 3: In a spherical right triangle, determine the deviation distance between the actual trajectory of the target and the great circle route according to the sine and cosine theorems of spherical triangles. The deviation distance represents the actual navigation accuracy; the navigation accuracy is assessed based on the deviation distance.

[0006] Preferably, in step one, the conversion formula from the 2000 Chinese Geodetic Coordinate System to the Geocentric Geodetic Coordinate System is:

[0007] in, These represent the distance from the point in the geocentric geodetic coordinate system to the Earth's center, the longitude in the geocentric geodetic coordinate system, and the latitude in the geocentric geodetic coordinate system, respectively. These are the geodetic longitude, geodetic latitude, and geodetic height of the points in the 2000 China Geodetic Coordinate System before the transformation; , For the Earth's semi-major axis, This is the first eccentricity.

[0008] Preferably, step two specifically comprises: Launch point in the geocentric Earth coordinate system Navigation points Earth's North Pole Forming a spherical triangle, the launch point in the geocentric coordinate system is determined by the fundamental theorem of spherical triangles. With navigation points Great Circle Route for:

[0009] in, It is the sum of the Earth's semi-major axis and its height. and Launch points In the geocentric coordinate system, latitude and longitude, and navigation points Latitude and longitude in the geocentric coordinate system; Launch point To navigation point Great circle course heading angle for: .

[0010] Preferably, step three includes: Step 31: Great Circle Route The trajectory points of the great circle route are segmented from the top, and the coordinates of the great circle route points are solved using the principle of spherical triangles. ; Step 32: For a point on the actual trajectory of the target Searching for great circle routes trajectory points on Make the arc With arc The included angle is 90°, then at this time The shortest length is The length is the target length. The deviation distance between the point and the Dayuan route indicates the target's location. Actual navigation accuracy of points ; Step 33: Given the assessment conditions, assess the navigation accuracy based on the deviation distance.

[0011] Preferably, step 31 specifically includes: launch point To the navigation point Great circle routes between Divided into The points on the great circle route are denoted as... , For point Distance to the Earth's core, For point Longitude in the geocentric Earth coordinate system For point Latitude in the geocentric coordinate system; Great Circle routes The interval between values ​​is Then point to launch point The great circle route distance is The heading angle for a great circle route is... ; Let the arc With arc The included angle is arc With arc The included angle is , , , These are the central angles of the corresponding arcs; according to the geometric relationships in the geocentric coordinate system: (I) and (II) in, and Launch points Latitude and longitude in the geocentric coordinate system; According to the fundamental theorem and formula of spherical triangles, we have spherical triangles Relationship: (III) First calculate according to formula (II) and Together with heading angle Substituting into formula (III), we obtain the solution. 、 、 Then and Substitute into formula (I) to calculate the trajectory points of the great circle route. coordinates , Combined with the known distances from points on the trajectory to the Earth's center Find the coordinates of the points on the great circle route. .

[0012] Preferably, step 32 specifically includes: Launch point in the known geocentric coordinate system Navigation points North Pole Trajectory points on the actual trajectory of the target The coordinates are taken from a point on the great circle route. ; arc With arc The included angle is arc With arc The included angle is According to the fundamental theorem of spherical triangles, there exists a circular arc. With arc The included angle is - ; When the arc With arc When the included angle is 90°, the arc The shortest length is achieved, meaning the distance between the actual trajectory and the theoretical great circle route is minimized; in a spherical right triangle... In this context, according to the sine theorem for spherical triangles, the deviation distance between the actual trajectory of the target and the great circle route is... The length is:

[0013] in For the Earth's semi-major axis, for B The point is high on the ground. For arc The central angle.

[0014] Preferably, the navigation accuracy assessment based on the deviation distance is as follows: Given the assessment criteria, including target navigation accuracy and stable flight distance ; If the navigation accuracy of the target on the actual trajectory Target navigation accuracy And maintain at least a stable flight distance If so, the assessment is passed.

[0015] Preferably, the navigation accuracy assessment based on the deviation distance further includes: Determine the target's navigation accuracy upon first entry. And maintain distance Time ; The smaller the value, the higher the target navigation accuracy.

[0016] Beneficial effects: This invention transforms the target's coordinates from the 2000 China Geodetic Coordinate System to the Geocentric Geodetic Coordinate System based on trajectory parameters. Then, it uses the fundamental theorem of spherical triangles to solve for the heading angles of the great circle route and the actual trajectory. Finally, it uses the sine and cosine theorems of spherical triangles within a spherical right triangle to calculate the deviation distance between the actual trajectory and the great circle route, thereby evaluating navigation accuracy. This scheme transforms the target navigation accuracy problem into a problem of the distance between the target's actual trajectory and the great circle route, simplifying the problem-solving approach, providing a concise and clear operation, high accuracy, and facilitating data processing. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the great circle route solution of the present invention.

[0018] Figure 2 This is a schematic diagram illustrating the error between the actual trajectory and the great circle route.

[0019] Figure 3 This is a schematic diagram comparing the longitude and latitude of a great circle route and its actual trajectory in the geocentric coordinate system.

[0020] Figure 4 This is a flowchart of the navigation accuracy assessment data processing method of the present invention. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0022] This invention provides a data processing method for navigation accuracy assessment. The basic idea is to transform the target's coordinates in the 2000 China Geodetic Coordinate System to the Geocentric Geodetic Coordinate System based on the trajectory parameters. Then, the heading angle of the great circle route and the heading angle of the actual trajectory are solved according to the fundamental theorem of spherical triangles. Finally, the deviation distance between the actual trajectory and the great circle route is solved in the spherical right triangle according to the sine and cosine theorems of spherical triangles, thereby evaluating the navigation accuracy.

[0023] As can be seen, this invention is the first to propose transforming the target navigation accuracy problem into a problem of target actual trajectory and great circle route distance through coordinate transformation, using the great circle route method and the spherical triangle theorem. This simplifies the problem-solving approach, makes the operation concise and clear, and provides high-precision results, making it convenient for data processing personnel to carry out processing work.

[0024] First, the principle of the method of this invention will be introduced.

[0025] Launch point in the 2000 Chinese geodetic coordinate system and navigation points The coordinates are transformed to the geocentric coordinate system, where ( The coordinates of the launch point and navigation point in the geocentric coordinate system are: longitude, latitude, and height, respectively. , ,in The distance from the launch point / navigation point to the Earth's center. The longitude of the launch / navigation point in the geocentric geodetic coordinate system. The latitude of the launch point / navigation point in the geocentric coordinate system. .

[0026] From the launch point A For example, the conversion formula is: (1) in , For the Earth's semi-major axis, This is the first eccentricity.

[0027] like Figure 1 As shown, the launch point in the geocentric Earth coordinate system Navigation points For two points on the Earth's ellipsoid, N If it is the Earth's North Pole, then , , N This forms a spherical triangle. By the fundamental theorem of spherical triangles, the launch point in the geocentric coordinate system can be obtained. With navigation points Great Circle Route for: (2) in, It is the sum of the Earth's semi-major axis and its height.

[0028] Great circle course heading angle between launch point and navigation point for: (3) arrive The great circle route trajectory points are The number of trajectory points is Great Circle Route The interval between values ​​is Then the trajectory point arrive The great circle route distance is .

[0029] like Figure 1 As shown, the arc With arc The included angle is arc With arc The included angle is . , , These are the central angles of the corresponding arcs. From the geometric relationships in the geocentric coordinate system, we have: (4) Solve the spherical triangle using the fundamental theorem and formula. : (5) According to the last two formulas of equation (4), we can obtain and The result obtained by combining formula (3) The result can be obtained using formula (5). ， ， ;Will and Substituting the first two formulas into formula (4), we can obtain and Combined with the known distances from points on the trajectory to the Earth's center Find the coordinates of the points on the great circle route. .

[0030] like Figure 2 As shown, the launch point in the known geocentric coordinate system navigation points North Pole trajectory points The coordinates are taken from a point on the great circle route. Make the arc N With arc The included angle is arc N With arc The included angle is According to the fundamental theorem of spherical triangles, there exists a circular arc. With arc The included angle is - .

[0031] When the arc With arc When the included angle is 90°, the arc The shortest length is achieved, meaning the distance between the actual trajectory and the theoretical great circle route is minimized. This occurs within a spherical right triangle. In the middle, according to the sine theorem of spherical triangles, the deviation distance between the actual trajectory and the great circle route is... The length is: (6) in =6378137 is the Earth's semi-major axis. for The point is high on the ground; For arc The central angle is a known quantity.

[0032] like Figure 3 As shown, the launch point in the geocentric Earth coordinate system and navigation points Coordinates, navigation accuracy Defined as the deviation distance between the actual trajectory and the great circle route. Given the assessment criteria, including target navigation accuracy... and stable flight distance If the navigation accuracy of the target on the actual trajectory Target navigation accuracy And maintain at least a stable flight distance If so, the assessment is passed.

[0033] Furthermore, it can also record the time when the target first stabilizes within the navigation accuracy range. Stable entry means maintaining navigation accuracy at the target. Flight at least kilometer. The smaller the value, the higher the target navigation accuracy.

[0034] Based on the above analysis, see Figure 4 The embodiment of the navigation accuracy assessment data processing method of the present invention includes the following steps: Step 1: Solve for the trajectory parameters to obtain the launch point in the 2000 China Geodetic Coordinate System. and navigation points coordinate.

[0035] Step 2: Based on coordinate transformation, adjust the launch point. and navigation points conversion to launch point in geocentric coordinate system and navigation points See formula (1).

[0036] Step 3: Based on the principle of spherical triangles, using the North Pole... Solve for the launch point With navigation points Great circle distance between and heading angle See formulas (2) and (3).

[0037] Step 4: Distance along the great circle route The system divides the path into multiple great circle trajectory points. Using the principle of spherical triangles, the coordinates of these great circle trajectory points are calculated. See formulas (4) and (5).

[0038] Step 5: Target a point on the actual trajectory of the objective. Find a point on the great circle route Make the arc With arc The included angle is 90°, then at this time The length is the shortest; The length is the target length. Point navigation accuracy .

[0039] Step 6: Given the assessment conditions, assess the navigation accuracy based on the deviation distance.

[0040] The assessment criteria include target navigation accuracy. and stable flight distance If the navigation accuracy of the target on the actual trajectory Target navigation accuracy And maintain at least a stable flight distance If so, the assessment is passed; Determine the target's navigation accuracy upon first entry. And maintain distance Time ; The smaller the value, the higher the target navigation accuracy.

[0041] This concludes the process.

[0042] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A navigation accuracy verification data processing method, characterized by, The target navigation precision problem is converted into a target actual trajectory and a great circle distance problem, and the method comprises the following steps: Step 1: determining a launch point and a navigation point according to trajectory parameters, and converting from a China Geodetic Coordinate System to a Geocentric Great Earth Coordinate System; Step 2: solving a great circle route between the launch point and the navigation point according to a spherical triangle basic theorem; Step 3: determining a deviation distance between the target actual trajectory and the great circle route according to a spherical triangle cosine and sine theorem in a spherical right triangle, and the deviation distance represents an actual navigation precision; and performing a navigation precision examination according to the deviation distance.

2. The method of claim 1, wherein, In the step 1, a conversion formula from the 2000 China Geodetic Coordinate System to the Geocentric Great Earth Coordinate System is as follows: wherein, respectively the distance from the point to the center of the earth in the geocentric big earth coordinate system, the longitude in the geocentric big earth coordinate system and the latitude in the geocentric big earth coordinate system; respectively the geodetic longitude, the geodetic latitude and the geodetic height of the point in the 2000 Chinese Geodetic Coordinate System before conversion; , is the long semi-axis of the earth, is the first eccentricity.

3. The method of claim 1, wherein, The step 2 specifically comprises: Launch point in the geocentric Earth coordinate system Navigation points Earth's North Pole Forming a spherical triangle, the launch point in the geocentric coordinate system is determined by the fundamental theorem of spherical triangles. With navigation points Great Circle Route for: wherein, is the sum of the Earth's semi-major axis and the geodetic height, and are the latitude and longitude, respectively, of the launch point in the geocentric geodetic coordinate system, and are the latitude and longitude, respectively, of the navigation point in the geocentric geodetic coordinate system. transmitting point to the navigation point between the great circle course angle is: 。 4. The method of claim 1, wherein, The step 3 comprises: Step 31: On the great circle route The upper part is divided into great circle route track points, and the coordinates of the great circle route track points are solved by using the spherical triangle principle ; Step 32: find the track point on the great circle route for a point on the target actual track ;​​​​​​​​​ Step 33: performing the navigation precision examination according to the deviation distance under a given examination condition.

5. The method of claim 4, wherein, The step 31 specifically comprises: The great circle route between the launch point and the navigation point is divided into great circle route track points, denoted as , The distance from the point to the center of the earth is The geocentric geodetic coordinate system longitude of the point is The geocentric geodetic coordinate system latitude of the point is The value interval of the great circle route is The great circle route distance from the point to the launch point is The heading angle of the great circle route is ​​ Set the angle between the arc and the arc is , the angle between the arc and the arc is , , , respectively the central angle of the corresponding arc; from the geometry of the geocentric earth coordinate system, we have: （I） And (I) wherein and are the transmit points latitude and longitude in the geocentric terrestrial coordinate system; According to the spherical triangle basic theorem and formula, there is a spherical triangle relationship: (III) First, according to formula (II), calculate and , together with the heading angle Substitute into formula (III) to obtain 、 、 ; then substitute and into formula (I) to calculate the coordinates of the great circle track point , , in combination with the known distance from the track point to the center of the earth , to obtain the great circle track point coordinates .​ 6. The method of claim 4, wherein, The step 32 specifically comprises: Coordinates of the launch point, the navigation point, the north pole, the target actual trajectory point, and the point on the great circle route in the geocentric big earth coordinate system ​​​​​​​​​​​​​​​ When the arc With arc When the included angle is 90°, the arc The shortest length is achieved, meaning the distance between the actual trajectory and the theoretical great circle route is minimized; in a spherical right triangle... In this context, according to the sine theorem for spherical triangles, the deviation distance between the actual trajectory of the target and the great circle route is... The length is: wherein is the earth's semi-major axis, is B the geodetic height of the point, is the central angle of the circular arc .

7. The method of claim 1 or 4, wherein, The navigation precision examination according to the deviation distance is as follows: Given the conditions of the examination, including target navigation accuracy and stable flight distance ; If the target is on the actual trajectory The target navigation accuracy And at least keep the stable flight distance , then the examination is qualified.

8. The method of claim 7, wherein, The navigation precision examination according to the deviation distance further comprises: determining target first entry target navigation accuracy and keep distance of time ; The smaller the target navigation accuracy represents the higher.

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