Method for determining air operation procedures under obstacles shielding civil aviation radar

Abstract

The present invention discloses a method for determining an air operation program under the obstruction of civil aviation radar by obstacles, and belongs to the field of civil aviation air traffic control monitoring technology. The method of the present invention comprises the following steps: S1. Extracting the air operation program parameters of the civil aviation airport that needs to be analyzed, and establishing a flight trajectory model; S2. Establishing a radar model according to the parameters of the radar equipment to be analyzed; S3. Extracting the parameters of the obstacles to be analyzed, and establishing an obstacle model; S4. Calculating the horizontal and vertical obstruction ranges of the obstruction of the radar by the obstacles, so as to determine the spatial obstruction range of the radar obstructed by the obstacles; S5. Accurately determine the air operation program affected by the obstacles according to the spatial obstruction range of the radar obstructed by the obstacles. The method of the present invention can quickly and accurately lock the affected air operation program from hundreds of programs, greatly improving the efficiency and accuracy of the analysis of radar professionals.

Description

Technical Field

[0001] The invention belongs to the technical field of civil aviation air traffic control monitoring, and in particular relates to a method for determining an air operation procedure under the shielding of civil aviation radar by obstacles. Background Art

[0002] The aerial flight procedures around radars are extremely complex. With the development of cities, a large number of obstacles have appeared around radars, which have had a great impact on radars. How to accurately lock the aerial flight procedures around radars that may be affected by obstacles has always been a pain point in the industry.

[0003] Most of the obstacles around the radar are located between the transmitting antenna of the civil aviation radar and the receiving antenna of the aircraft in the air. Due to the high height of these obstacles, the radar transmission signal forms a large shielding range behind them, which seriously affects the radar transmission signal. The shielding range has a certain shape. Within this range, the radar signal strength received by the aircraft will be lower than the threshold value of the airborne radar receiver, resulting in the inability of the aircraft in the air to receive the signal transmitted by the civil aviation ground radar, which has a great impact on the operation of the civil aviation radar.

[0004] The air operation procedures around the airport radar include the sectors of the minimum surveillance and guidance altitude, the approach control area, the area control area, the fuel dumping area, the flight procedures and the high-altitude routes, which range from dozens to hundreds. Figure 2 shown. Figure 2 The sectors in the analysis include the guidance altitude sectors, approach control areas, area control areas and fuel dumping areas, and the procedures include flight procedures and high-altitude routes. In the process of analyzing the impact of obstacles on radar, the current common practice is to use the air operation procedures used as the analysis object, which leads to a very large amount of analysis and calculation, greatly reducing the efficiency of the analysis. In addition, there is currently no unified method for accurately calculating the horizontal and vertical obstruction ranges of obstacles to civil aviation secondary radars; and the accuracy of the existing analysis is not enough. More importantly, there is also a lack of a unified method for how to use these obstruction ranges to quickly determine which sectors and procedures will be affected in a large number of air operation procedures.

[0005] Patents with publication number CN114781190A, "A radar detection capability simulation method and device" and patents with publication number CN114781191A, "A radar detection capability simulation method and device in complex electromagnetic environment", proposed radar detection capability simulation methods and devices, mainly analyzing how to detect target signals from the perspective of echo, but neither involved the specific shielding range of the radar. The document "Research and Development of Radar Controlled Airspace Signal Coverage Evaluation System" (Liu Jiarong. North China University of Technology, 2009.), combined with antenna signal shielding theory and application basis, proposed an algorithm for calculating line-of-sight propagation signal coverage. However, this method equates line-of-sight coverage with radar coverage, which is unscientific. The document "Analyzing Coverage Performance Using Secondary Radar Recording Data" (Wu Shengqian, Fu Hong. Science and Technology Innovation Herald, 2020, 17(11):4-5.) proposes to introduce a digital elevation model (DEM) and use the line-of-sight analysis tool provided by Global Mapper (geographic information system software) to set the radar station antenna height and the coverage altitude layer to be analyzed for judgment analysis. This analysis method also equates line-of-sight analysis with radar analysis results. However, electromagnetic waves above the ground propagate on a curved surface, so this method is not suitable for radar analysis. "Research on the Effective Range and Coverage Problems of Air Traffic Control Radar Radiation Signals" (Wen Bingmei. Civil Aviation University of China, 2007.) points out that the propagation path of radar is not a straight line propagation, but is refracted by atmospheric conditions, causing the electromagnetic wave rays to bend toward the earth, thereby increasing the direct line-of-sight distance of the radar signal. This means that it is unscientific to rely on software to perform line-of-sight coverage analysis to analogize the radar range. The civil aviation industry standard MH / T4003.2-2014 "Civil Aviation Communication Navigation Monitoring Station (Station) Installation Site Specification Part 2: Monitoring" points out that there is a significant difference between the radar shielding calculation formula and the line-of-sight calculation results. In summary, there is no unified standard for the calculation of the vertical shielding range of radar, and different researchers have different understandings and application methods. The existing technology has not yet correctly established the relationship between the vertical shielding of radar and the line-of-sight.

[0006] The civil aviation industry standard MH / T4003.2-2014 "Civil Aviation Communication Navigation Monitoring Station (Station) Installation Site Specification Part 2: Monitoring" proposes a radar shielding calculation formula, but this method can only calculate the vertical shielding range caused by obstacles to the radar, and cannot calculate the horizontal shielding width. The literature "Radar Shielding Angle Calculation and Impact Analysis" (Han Dan, Gao Haoran. Science and Technology and Innovation, 2018, (21): 9-11. DOI: 10.15913 / j.cnki.kjycx.2018.21.009.) also only determines the shielding range from the perspective of the vertical shielding range of the radar, and does not involve the horizontal shielding range of the obstacle. Therefore, there is currently no method to calculate the horizontal shielding range after the obstacle blocks the radar.

[0007] In summary, the problems existing in the prior art include the following three points:

[0008] (1) The number of airborne operation programs around airport radars is large and complex. The existing technology takes all airborne operation programs as analysis objects, resulting in a very large amount of analysis and calculation, and low analysis efficiency.

[0009] (2) In terms of vertical shielding calculation, existing technologies either refer to line-of-sight analysis or rely on the radar shielding angle formula in the civil aviation industry standard MH / T4003.2-2014, but no unified method has been formed. It is necessary to establish the correct relationship between radar vertical shielding and line-of-sight and to quickly obtain radar coverage height, and the relationship between the two is also missing in current research.

[0010] (3) Currently, there is no method to calculate the horizontal obstruction range of the radar after an obstacle blocks it.

[0011] Therefore, it is necessary to combine the obstacle parameters and radar parameters to calculate the horizontal and vertical obstruction ranges of the obstacles to the civil aviation secondary radar, and combine them with the air operation procedures to accurately determine the affected air operation procedures, and screen out the objects that need to be analyzed from a large number of sectors and flight procedures, forming a complete method for determining the air operation procedures under the obstruction of civil aviation radar by obstacles. Summary of the invention

[0012] The purpose of the present invention is to provide a method for determining an air operation procedure under the obstruction of civil aviation radar by obstacles, so as to solve the problems of large amount of calculation, low calculation efficiency and low accuracy in the prior art.

[0013] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0014] The method for determining the air operation procedure under the obstruction of civil aviation radar by obstacles disclosed in the present invention comprises the following steps:

[0015] S1. Extract the air operation procedure parameters of the civil aviation airport to be analyzed and establish a flight trajectory model; the air operation procedure parameters include air area, flight procedure and high-altitude route information; the air area includes the minimum surveillance guidance altitude sector, approach control area, area control area and fuel release area;

[0016] S2. Establishing a radar model according to the radar equipment parameters to be analyzed; the radar equipment parameters include the 1985 national elevation of the radar antenna phase center, the WGS-84 latitude and longitude coordinates of the radar antenna phase center, and the radar antenna operating frequency;

[0017] S3. Extract the parameters of the obstacle to be analyzed and establish an obstacle model; the parameters of the obstacle include the WGS-84 longitude and latitude coordinates of the boundary points and the center point of the obstacle, the 1985 national elevation of the highest point of the obstacle, and the length and width of the obstacle;

[0018] S4. Calculate the horizontal and vertical shielding ranges of the radar caused by the obstacle, so as to determine the spatial shielding range of the radar caused by the obstacle;

[0019] S5. Accurately determine the air operation procedures affected by obstacles based on the spatial obstruction range of the obstacle blocking the radar.

[0020] In some embodiments of the present invention, in step S4, the horizontal width of the radar shielding caused by the obstacle is calculated according to the following formula:

[0021] ;

[0022] Where W is the horizontal width of the radar shielding caused by the obstacle at the air positioning point outside the obstacle, in meters; λ is the radar wavelength, in meters; λ=c / f, c is the speed of light, and its value is 3×10 8 m / s, f is the radar operating frequency, its value is 1030MHz; D is the path length of the radar wave reflection signal, the unit is m;

[0023] Calculated based on the calculated W value :

[0024] ;

[0025] Where ds is the distance between the obstacle and the center point of the radar horizontal phase, in km; is the angle of the horizontal width W relative to the radar at the position ds with the radar as the center point;

[0026] The horizontal angle of the horizontal occlusion range is [( - ), + )];in The radar is the center point, due north is 0°, and the angle of the obstacle center point relative to the radar.

[0027] In some embodiments of the present invention, in step S4, the vertical height calculation formula of the obstacle shielding the radar is as follows:

[0028] ;

[0029] Where hr is the vertical height of the radar shielded by the obstacle at the aerial positioning point, in meters;

[0030] ho is the optical line-of-sight coverage height of obstacles at the aerial positioning point, in meters;

[0031] d is the distance between the airborne positioning point and the radar horizontal phase center point, in km;

[0032] ds is the distance between the obstacle and the center point of the radar horizontal phase, in km;

[0033] The vertical obstruction range at the radar position ds is [0, hr].

[0034] In some implementations of the present invention, in step S5, after determining the horizontal shielding range and the vertical shielding range of the obstacle shielding radar, first determine whether the air operation program is within the horizontal shielding range of the obstacle, if the air operation program is not within the horizontal shielding range of the obstacle, then do not consider the air operation program;

[0035] If the aerial program is within the horizontal occlusion range of the obstacle, it is determined whether it is within the vertical occlusion range of the obstacle; if it is within the vertical occlusion range of the obstacle, the aerial program is selected as an object that is affected by the obstacle and needs to be analyzed.

[0036] In some implementations of the present invention, in step S5, when determining whether the airborne operating program is within the horizontal shielding range of the obstacle, the angular range of the airborne operating program relative to the radar is first calculated, and then the determination is made;

[0037] (1) For the air area, the angle range relative to the radar is calculated using the following method:

[0038] Assume that the WGS-84 longitude and latitude coordinates of the radar are (a0, b0), and the WGS-84 longitude and latitude coordinates of each corner point in the air area are (a i ,b i ), where a i Indicates latitude, b i Indicates longitude, i=1,2,3,4 ; Calculate the azimuth of each corner point in the air area relative to the radar in turn, and obtain the angle range of the minimum surveillance guidance altitude sector, approach control area, area control area, and oil dumping area relative to the radar. The angle range takes due north as 0 degrees as a reference, and determines the minimum and maximum values; The calculation method of the azimuth of each corner point in the air area relative to the radar is as follows:

[0039] First convert the angle from degrees to radians:

[0040]

[0041]

[0042]

[0043]

[0044] definition:

[0045]

[0046]

[0047]

[0048] Each corner point relative to the radar azimuth The discriminant of is:

[0049] ;

[0050] (2) For the flight procedure and high altitude route, the angular range relative to the radar is calculated using the following method:

[0051] Extract the starting and ending points of the flight program and high-altitude route, determine the WGS-84 longitude and latitude coordinates of the starting and ending points, combine the WGS-84 longitude and latitude coordinates of the radar, and use the same method as the azimuth of the corner points of the air area relative to the radar to calculate the azimuth of the starting and ending points relative to the radar, and determine the angle range; the angle range is based on the true north as 0 degrees, and the minimum and maximum values ​​are determined;

[0052] The angle range calculated above is as follows: - ), + )], or partially intersects with it, then the aerial operation program corresponding to the angle range is determined to be within the horizontal occlusion range of the obstacle, and it is necessary to continue to determine whether it is within the vertical occlusion range of the obstacle;

[0053] If the angle range calculated above is within [( - ), + )] range, the aerial operation program corresponding to this angle range will not be considered.

[0054] In some implementation schemes of the present invention, when determining whether an aerial operation program is within the vertical shielding range of an obstacle, the following steps are performed for the aerial area:

[0055] First, determine the lowest operating altitude of a certain air area that needs to be calculated;

[0056] Calculate the maximum distance between the location of the air area to be calculated and the radar, and calculate hr1 at the closest distance and the farthest distance;

[0057] ;

[0058] Where hr1 is the vertical height of the obstacle shielding the radar at the farthest distance in the air area to be calculated, in meters;

[0059] ho1 is the optical line-of-sight coverage height of the obstacle at the farthest distance in the aerial area to be calculated, in meters;

[0060] d1 is the distance from the farthest distance of the air area to be calculated to the center point of the radar horizontal phase, in km;

[0061] ds is the distance between the obstacle and the center point of the radar horizontal phase, in km;

[0062] The vertical obstruction range at the distance ds from the radar is [0, hr1];

[0063] Compare the minimum use altitude with the maximum value hr1 of the vertical blocking range of the obstacle. If the minimum use altitude is less than the maximum value hr1 of the vertical blocking range, the aerial area is selected as the object that needs to be analyzed due to the influence of the obstacle; if the minimum use altitude is greater than the maximum value hr1 of the vertical blocking range, the aerial area is not an object that needs to be analyzed.

[0064] According to the above method, all aerial areas are analyzed and judged one by one, and the aerial area analysis is completed.

[0065] In some implementations of the present invention, when determining whether an aerial operation program is within the vertical shielding range of an obstacle, the following steps are performed for the flight program and the high-altitude route:

[0066] First, determine the minimum safe operating altitude of a certain flight procedure or high-altitude route that needs to be calculated;

[0067] Extract the starting point and ending point of the flight procedure or high-altitude route to be calculated within the horizontal range, determine the WGS-84 longitude and latitude coordinates of the starting point and the ending point, combine the WGS-84 longitude and latitude coordinates of the radar, calculate the distance from the starting point to the radar within the horizontal range and the distance from the ending point to the radar, and calculate the hr2 at the farthest distance;

[0068] ;

[0069] Where hr2 is the vertical height of the obstacle shielding the radar at the farthest distance, in meters;

[0070] ho2 is the optical sight coverage height of the obstacle at the farthest distance, in meters;

[0071] d2 is the distance from the farthest distance to the center point of the radar horizontal phase, in km;

[0072] ds is the distance between the obstacle and the center point of the radar horizontal phase, in km;

[0073] The vertical obstruction range at the radar position ds is [0, hr2];

[0074] Compare the minimum safe operating altitude with the maximum value of the vertical obstruction range hr2; if the minimum safe operating altitude is less than the maximum value of the vertical obstruction range hr2, then the flight procedure or high-altitude route is listed as an object to be analyzed; if the minimum safe operating altitude is greater than the maximum value of the vertical obstruction range hr2, then the flight procedure or high-altitude route is not listed as an object to be analyzed;

[0075] According to the above method, all flight procedures and high-altitude routes are analyzed and judged one by one, and the analysis of flight procedures and high-altitude routes is completed.

[0076] Compared with the prior art, the present invention has the following beneficial effects:

[0077] The present invention establishes a unified method for quickly determining which air areas, flight procedures, and high-altitude route information will be affected in a large number of air operation programs, and can quickly and accurately lock in the affected air operation programs from hundreds of programs. The present invention quickly and accurately screens out the air operation programs that may be potentially affected from a large number of air operation programs based on the horizontal occlusion range and vertical occlusion range of the impact range caused by the obstacle, thereby quickly locking in several affected programs from dozens or hundreds of programs. The method of the present invention can greatly improve the efficiency and accuracy of analysis by practitioners in radar operation units.

[0078] Based on the radar shielding angle formula specified in the traditional MH / T4003.2-2014 "Civil Aviation Communication Navigation Monitoring Station (Station) Installation Site Specification Part 2: Monitoring", the present invention combines the shielding angle measurement results to study the relationship between optical line-of-sight propagation and radar signal propagation, thereby obtaining the vertical range of radar signals based on line-of-sight conditions, and forming a new calculation method. Using this method in subsequent calculations, once the calculation personnel know the line-of-sight height of the position to be calculated, the radar's effective height can be immediately obtained; at the same time, the difference between line-of-sight and radar range at different distances can be obtained.

[0079] The present invention innovatively establishes a method for calculating the horizontal obstruction range of the radar after the obstacle obstructs it. The horizontal range is not a straight line extension from the radar to the edge angles on both sides of the obstacle. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] Figure 1 It is a schematic diagram of the overall process of the method of the present invention;

[0081] Figure 2 A schematic diagram of the air area, flight procedures and high-altitude routes around the radar;

[0082] Figure 3 It is a schematic diagram of the horizontal angle of the obstacle relative to the radar;

[0083] Figure 4 This is a schematic diagram of the spatial obstruction range caused by obstacles to the radar, where the upper figure is a schematic diagram of the vertical obstruction height, and the lower figure is a schematic diagram of the horizontal width obstruction;

[0084] Figure 5 Schematic diagram of the difference between the vertical height of the sight distance blocked by obstacles and the height of the sight distance blocked by obstacles in the present invention; the left figure is a schematic diagram of direct and reflected signals, and the right figure is a shadow cross-sectional diagram of the calculated width (the phase difference at point A is 0 degrees, and the phase difference at point B is 90 degrees);

[0085] Figure 6 A schematic diagram of the relationship between the radar sight range and radar coverage height at a certain location;

[0086] Figure 7 It is a schematic diagram of the vertical action range of the radar of the present invention and the line of sight (the relationship between (ho-hr) and d, ds);

[0087] Figure 8 The invention discloses a schematic diagram for quickly and accurately screening out affected program diagrams using the method of the invention. DETAILED DESCRIPTION

[0088] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0089] The present invention discloses a method for determining an air operation procedure under the obstruction of civil aviation radar by obstacles, and the process thereof is as follows: Figure 1 As shown, the specific steps include:

[0090] S1. Extract the air operation procedure parameters of the civil aviation airport to be analyzed and establish a flight trajectory model; the air operation procedure parameters include air area, flight procedure and high-altitude route information; the air area includes the minimum surveillance guidance altitude sector, approach control area, area control area and fuel release area;

[0091] S2. Establishing a radar model according to the radar equipment parameters to be analyzed; the radar equipment parameters include the 1985 national elevation of the radar antenna phase center, the WGS-84 latitude and longitude coordinates of the radar antenna phase center, and the radar antenna operating frequency;

[0092] S3. Extract the parameters of the obstacle to be analyzed and establish an obstacle model; the parameters of the obstacle include the WGS-84 longitude and latitude coordinates of the boundary points and the center point of the obstacle, the 1985 national elevation of the highest point of the obstacle, and the length and width of the obstacle;

[0093] S4. Calculate the horizontal and vertical obstruction ranges of the radar caused by obstacles, so as to determine the spatial obstruction range of the radar caused by obstacles. The spatial obstruction range caused by the radar is shown in the attached figure. Figure 4 As shown;

[0094] S4.1 Calculate the horizontal obstruction range of the radar caused by obstacles

[0095] A typical cross section of an obstacle occlusion is Figure 5 As shown. Assuming there is reflection from a metal object, the direct and reflected signals will be in anti-phase. At point A, the path difference is zero, resulting in the deepest obstruction; at point B, the path difference is λ / 2, and the direct and reflected signals combine to give a maximum. Successive maxima appear where the path difference is (2n+1)λ / 2, where n is an integer. Since the interfering signal is weaker at larger angles from the forward scattering direction, these maxima become weaker. A conservative estimate of the width of the obstacle obstruction is determined by the locus of points formed by point B.

[0096] The path difference Δ between the direct and reflected signals at the receiver is calculated as follows:

[0097] (1);

[0098] Where X is the length of the radar wave direct signal path, in meters;

[0099] D is the path length of the radar wave reflection signal, in meters;

[0100] By setting the path difference Δ = λ / 2 and solving for the half-width W, the locus of points of the occlusion width defined at a distance W beyond the obstacle can be found:

[0101] (2);

[0102] (3);

[0103] If λ is much smaller than D, then formula (3) can be simplified to:

[0104] (4);

[0105] Where W is the horizontal width of the radar shielding caused by the obstacle at the air positioning point outside the obstacle, in meters; λ is the radar wavelength, in meters; λ=c / f, c is the speed of light, and its value is 3×10 8 m / s, f is the radar operating frequency, its value is 1030MHz; D is the path length of the radar wave reflection signal, the unit is m;

[0106] Calculate from this :

[0107] (5);

[0108] Where ds is the distance between the obstacle and the center point of the radar horizontal phase, in km; is the angle of the horizontal width W relative to the radar at the position ds with the radar as the center point;

[0109] The horizontal angle of the horizontal occlusion range is [( - ), + )];in The radar is the center point, due north is 0°, and the angle of the obstacle center point relative to the radar is as follows: Figure 3 shown.

[0110] S4.2 Calculate the vertical extent of radar obscuration by obstacles

[0111] S4.2.1 Determine the radar range based on the line-of-sight range. The vertical range of obstacles shielding the radar is as follows: Figure 6 shown.

[0112] Calculate according to the shielding angle calculation formula:

[0113] (6);

[0114] When calculating the optical line of sight, K=7 / 6; when calculating the radar shielding, K=4 / 3.

[0115] In formula (6), d is the distance between the airborne positioning point and the radar horizontal phase center point, in km;

[0116] h is the height of the obstacle, in meters;

[0117] ha is the radar antenna height, in meters;

[0118] The shielding angle of the optical viewing distance is , the radar shielding angle is , according to formula (6) and .

[0119] (7);

[0120] (8);

[0121] In formula (7) and formula (8), ds is the distance between the obstacle and the center point of the radar horizontal phase, in km;

[0122] Subtract formula (8) from formula (7) to obtain ;

[0123] (9);

[0124] The optical line of sight height at a certain position d is ho (unit: m), and the radar operating height is hr (unit: m). Formulas (10) and (11) can be established respectively from formulas (7) and (8):

[0125] (10);

[0126] (11);

[0127] Subtracting formula (11) from formula (10) yields:

[0128] (12);

[0129] As attached Figure 7 Attached Figure 7The horizontal axis is the distance d from any aerial positioning point to the radar horizontal phase center point, in km; the vertical axis is the difference between the optical line of sight height and the radar coverage height (ho-hr), in m. ds is the distance from the obstacle to the radar horizontal phase center point, in km. ds is represented by different colors, representing the change in the relationship between (ho-hr) and d at different distances.

[0130] It can be seen from this that, except when d = ds, the optical height at a certain azimuth is equal to the actual height of the radar, in other cases (d> ds), the actual range of the radar at any calculated position is somewhat different from the line of sight. When ds is a fixed value and the distance between the air positioning point continues to change and increase, the difference between the radar's lowest altitude and the line of sight altitude also gradually increases. For example, at a distance of 200km from the radar, the radar's range is about 300m longer than the line of sight range; at 450km at the edge of the radar coverage, the radar's range is about 1500m longer than the line of sight range. This means that using the line of sight method to simulate the radar's signal coverage will seriously underestimate the radar's true range of action and must be corrected.

[0131] S4.2.2 To determine the radar obstruction height at a given location, if the line-of-sight height ho is known, hr can be quickly calculated using the following formula:

[0132] ;

[0133] Where hr is the vertical height of the radar shielded by the obstacle at the aerial positioning point, in meters;

[0134] ho is the optical line-of-sight coverage height of obstacles at the aerial positioning point, in meters;

[0135] d is the distance between the airborne positioning point and the radar horizontal phase center point, in km;

[0136] ds is the distance between the obstacle and the center point of the radar horizontal phase, in km;

[0137] The vertical obstruction range at the radar position ds is [0, hr].

[0138] S5. After determining the horizontal and vertical obstruction ranges of the obstacle shielding radar, first determine whether the air operation procedure is within the horizontal obstruction range of the obstacle. If the air operation procedure is not within the horizontal obstruction range of the obstacle, then the air operation procedure will not be considered;

[0139] If the aerial program is within the horizontal occlusion range of the obstacle, it is determined whether it is within the vertical occlusion range of the obstacle; if it is within the vertical occlusion range of the obstacle, the aerial program is selected as an object that is affected by the obstacle and needs to be analyzed.

[0140] S51. When determining whether the airborne operation program is within the horizontal obstruction range of the obstacle, first calculate the angle range of the airborne operation program relative to the radar, and then make a judgment;

[0141] (1) For each sector at the minimum surveillance and guidance altitude, approach control area, area control area, fuel dumping area and other air areas, the following method is used to calculate the angle range relative to the radar:

[0142] Assume that the WGS-84 longitude and latitude coordinates of the radar are (a0, b0), and the WGS-84 longitude and latitude coordinates of each corner point of the sector are (a i ,b i ), where a i Indicates latitude, b i Indicates longitude, i=1,2,3,4 ; Calculate the azimuth of each corner point in the air area relative to the radar in turn, and obtain the angle range of the minimum surveillance guidance altitude sector, approach control area, area control area, and oil dumping area relative to the radar. The angle range is based on true north as 0 degrees to determine the minimum and maximum values; WGS-84 longitude and latitude are both in decimal point format, in degrees, and are retained to 4 decimal places;

[0143] The calculation method of each corner point of the air area relative to the radar azimuth is as follows:

[0144] First convert the angle from degrees to radians:

[0145]

[0146]

[0147]

[0148]

[0149] definition:

[0150]

[0151]

[0152]

[0153] Each corner point relative to the radar azimuth The discriminant of is:

[0154] ;

[0155] (2) For the flight procedure and high altitude route, the angular range relative to the radar is calculated using the following method:

[0156] Extract the starting and ending points of the flight program and high-altitude route, determine the WGS-84 longitude and latitude coordinates of the starting and ending points, combine the WGS-84 longitude and latitude coordinates of the radar, and use the same method as the azimuth of the corner points of the air area relative to the radar to calculate the azimuth of the starting and ending points relative to the radar, and determine the angle range; (the angle range is based on due north as 0 degrees, and the minimum and maximum values ​​are determined);

[0157] The angle range calculated above is as follows: - ), )], or partially intersects with it, then the aerial operation program corresponding to the angle range is determined to be within the horizontal occlusion range of the obstacle, and it is necessary to continue to determine whether it is within the vertical occlusion range of the obstacle;

[0158] If the angle range calculated above is not within [( - ), )], the aerial operation program corresponding to this angle range will not be considered.

[0159] S52. When determining whether the aerial operation program is within the vertical obstruction range of the obstacle,

[0160] (1) For each sector at the minimum surveillance and guidance altitude, approach control area, area control area, fuel dumping area and other air areas, proceed as follows:

[0161] First, determine the lowest operating altitude of a certain air area that needs to be calculated;

[0162] Calculate the maximum distance between the location of the air area to be calculated and the radar, and calculate hr1 at the closest distance and the farthest distance;

[0163] ;

[0164] Where hr1 is the vertical height of the obstacle shielding the radar at the farthest distance in the air area to be calculated, in meters;

[0165] ho1 is the optical line-of-sight coverage height of the obstacle at the farthest distance in the aerial area to be calculated, in meters;

[0166] d1 is the distance from the farthest distance of the air area to be calculated to the center point of the radar horizontal phase, in km;

[0167] ds is the distance between the obstacle and the center point of the radar horizontal phase, in km;

[0168] The vertical obstruction range at the distance ds from the radar is [0, hr1];

[0169] Compare the minimum operating altitude with the maximum value hr1 of the vertical blocking range of the obstacle. If the minimum operating altitude is less than the maximum value hr1 of the vertical blocking range, the aerial area is selected as the object affected by the obstacle and needs to be analyzed; if the minimum operating altitude is greater than the maximum value hr1 of the vertical blocking range, the aerial area is not an object that needs to be analyzed.

[0170] (2) For flight procedures and high-altitude routes, proceed as follows:

[0171] First, determine the minimum safe operating altitude of a certain flight procedure or high-altitude route that needs to be calculated;

[0172] Extract the starting point and ending point of the flight procedure or high-altitude route to be calculated within the horizontal range, determine the WGS84 longitude and latitude coordinates of the starting point and the ending point by coordinate conversion, and calculate the distance from the starting point to the radar and the distance from the ending point to the radar within the horizontal range by combining the WGS84 longitude and latitude coordinates of the radar, and calculate the hr2 at the farthest distance;

[0173] ;

[0174] Where hr2 is the vertical height of the obstacle shielding the radar at the farthest distance, in meters;

[0175] ho2 is the optical sight coverage height of the obstacle at the farthest distance, in meters;

[0176] d2 is the distance from the farthest distance to the center point of the radar horizontal phase, in km;

[0177] ds is the distance between the obstacle and the center point of the radar horizontal phase, in km;

[0178] The vertical obstruction range at the radar position ds is [0, hr2];

[0179] The minimum safe operating altitude is compared with the maximum value hr2 of the vertical obstruction range. If the minimum safe operating altitude is less than the maximum value hr2 of the vertical obstruction range, then the flight procedure or high-altitude route is listed as an object to be analyzed; if the minimum safe operating altitude is greater than the maximum value hr2 of the vertical obstruction range, then the flight procedure or high-altitude route is not listed as an object to be analyzed.

[0180] The method of the present invention can quickly and accurately screen out the affected programs, such as the attached Figure 8 shown. Figure 8 The sectors include guidance altitude sectors, approach control areas, area control areas and fuel dumping areas, and the procedures include flight procedures and high-altitude routes.

[0181] Finally, it should be noted that the above embodiments are only preferred embodiments of the present invention to illustrate the technical solution of the present invention, but not to limit it, and certainly not to limit the patent scope of the present invention. Any changes or modifications that are made to the main design concept and spirit of the present invention without any substantial meaning, and the technical problems they solve are still consistent with the present invention, should be included in the protection scope of the present invention; in addition, the direct or indirect application of the technical solution of the present invention in other related technical fields is also included in the patent protection scope of the present invention.

Claims

1. A method for determining air operation procedures under the obstruction of civil aviation radar by obstacles, characterized in that: The following steps are involved: S1. Extract the air operation procedure parameters of the civil aviation airport to be analyzed and establish a flight trajectory model; the air operation procedure parameters include air area, flight procedure and high-altitude route information; the air area includes the minimum surveillance guidance altitude sector, approach control area, area control area and fuel release area; S2. Establishing a radar model according to the radar equipment parameters to be analyzed; the radar equipment parameters include the 1985 national elevation of the radar antenna phase center, the WGS-84 latitude and longitude coordinates of the radar antenna phase center, and the radar antenna operating frequency; S3. Extract the parameters of the obstacle to be analyzed and establish an obstacle model; the parameters of the obstacle include the WGS-84 longitude and latitude coordinates of the boundary points and the center point of the obstacle, the 1985 national elevation of the highest point of the obstacle, and the length and width of the obstacle; S4. Calculate the horizontal and vertical shielding ranges of the radar caused by the obstacle, so as to determine the spatial shielding range of the radar caused by the obstacle; S5. Accurately determine the air operation procedures affected by obstacles based on the spatial obstruction range of the obstacle blocking the radar.

2. The method for determining the air operation procedure under the obstruction of civil aviation radar by obstacles according to claim 1 is characterized in that: In step S4, the horizontal width of the radar shielding caused by the obstacle is calculated according to the following formula: ； Where W is the horizontal width of the radar shielding caused by the obstacle at the air positioning point outside the obstacle, in meters; λ is the radar wavelength, in meters; λ=c / f, c is the speed of light, and its value is 3×10 8 m / s, f is the radar operating frequency, its value is 1030MHz; D is the path length of the radar wave reflection signal, the unit is m; Calculated based on the calculated W value : ； Where ds is the distance between the obstacle and the center point of the radar horizontal phase, in km; is the angle of the horizontal width W relative to the radar at the position ds with the radar as the center point; The horizontal angle of the horizontal occlusion range is [( - ), + )];in The radar is the center point, due north is 0°, and the angle of the obstacle center point relative to the radar.

3. The method for determining the air operation procedure under the obstruction of civil aviation radar by obstacles according to claim 1 is characterized in that: In step S4, the vertical height calculation formula of the obstacle shielding the radar is as follows: ； Where hr is the vertical height of the radar shielded by the obstacle at the aerial positioning point, in meters; ho is the optical line-of-sight coverage height of obstacles at the aerial positioning point, in meters; d is the distance between the airborne positioning point and the radar horizontal phase center point, in km; ds is the distance between the obstacle and the center point of the radar horizontal phase, in km; The vertical obstruction range at the radar position ds is [0, hr].

4. The method for determining the air operation procedure under the obstruction of civil aviation radar by obstacles according to any one of claims 1 to 3, characterized in that: In step S5, after determining the horizontal shielding range and the vertical shielding range of the obstacle shielding radar, first determine whether the air operation program is within the horizontal shielding range of the obstacle. If the air operation program is not within the horizontal shielding range of the obstacle, then do not consider the air operation program; If the aerial program is within the horizontal occlusion range of the obstacle, it is determined whether it is within the vertical occlusion range of the obstacle; if it is within the vertical occlusion range of the obstacle, the aerial program is selected as an object that is affected by the obstacle and needs to be analyzed.

5. The method for determining the air operation procedure under the obstruction of civil aviation radar by obstacles according to claim 4 is characterized in that: In step S5, when determining whether the aerial operation program is within the horizontal obstruction range of the obstacle, first calculate the angle range of the aerial operation program relative to the radar, and then make a determination; (1) For the air area, the angle range relative to the radar is calculated using the following method: Assume that the WGS-84 longitude and latitude coordinates of the radar are (a0, b0), and the WGS-84 longitude and latitude coordinates of each corner point in the air area are (a i ,b i ), where a i Indicates latitude, b i Indicates longitude, i=1,2,3,4 ; Calculate the azimuth of each corner point in the air area relative to the radar in turn, and obtain the angle range of the minimum surveillance guidance altitude sector, approach control area, area control area, and oil dumping area relative to the radar. The angle range takes due north as 0 degrees as a reference, and determines the minimum and maximum values; The calculation method of the azimuth of each corner point in the air area relative to the radar is as follows: First convert the angle from degrees to radians: definition: Each corner point relative to the radar azimuth The discriminant of is: ； (2) For the flight procedure and high altitude route, the angular range relative to the radar is calculated using the following method: Extract the starting and ending points of the flight program and high-altitude route, determine the WGS-84 longitude and latitude coordinates of the starting and ending points, combine the WGS-84 longitude and latitude coordinates of the radar, and use the same method as the azimuth of the corner points of the air area relative to the radar to calculate the azimuth of the starting and ending points relative to the radar, and determine the angle range; the angle range is based on the true north as 0 degrees, and the minimum and maximum values ​​are determined; The angle range calculated above is as follows: - ), + )], or partially intersects with it, then the aerial operation program corresponding to the angle range is determined to be within the horizontal occlusion range of the obstacle, and it is necessary to continue to determine whether it is within the vertical occlusion range of the obstacle; If the angle range calculated above is within [( - ), + )] range, the aerial operation program corresponding to this angle range will not be considered.

6. The method for determining the air operation procedure under the obstruction of civil aviation radar by obstacles according to claim 5 is characterized in that: When determining whether the aerial program is within the vertical obstruction range of obstacles, follow the following steps for the aerial area: First, determine the lowest operating altitude of a certain air area that needs to be calculated; Calculate the maximum distance between the location of the air area to be calculated and the radar, and calculate hr1 at the closest distance and the farthest distance; ； Where hr1 is the vertical height of the obstacle shielding the radar at the farthest distance in the air area to be calculated, in meters; ho1 is the optical line-of-sight coverage height of the obstacle at the farthest distance in the aerial area to be calculated, in meters; d1 is the distance from the farthest distance of the air area to be calculated to the center point of the radar horizontal phase, in km; ds is the distance between the obstacle and the center point of the radar horizontal phase, in km; The vertical obstruction range at the distance ds from the radar is [0, hr1]; Compare the minimum use altitude with the maximum value hr1 of the vertical blocking range of the obstacle. If the minimum use altitude is less than the maximum value hr1 of the vertical blocking range, the aerial area is selected as the object that needs to be analyzed due to the influence of the obstacle; if the minimum use altitude is greater than the maximum value hr1 of the vertical blocking range, the aerial area is not an object that needs to be analyzed. According to the above method, all aerial areas are analyzed and judged one by one, and the aerial area analysis is completed.

7. The method for determining the air operation procedure under the obstruction of civil aviation radar by obstacles according to claim 5 is characterized in that: When determining whether the aerial operation program is within the vertical obstruction range of obstacles, follow the following steps for the flight program and high-altitude route: First, determine the minimum safe operating altitude of a certain flight procedure or high-altitude route that needs to be calculated; Extract the starting point and ending point of the flight procedure or high-altitude route to be calculated within the horizontal range, determine the WGS-84 longitude and latitude coordinates of the starting point and the ending point, combine the WGS-84 longitude and latitude coordinates of the radar, calculate the distance from the starting point to the radar within the horizontal range and the distance from the ending point to the radar, and calculate the hr2 at the farthest distance; ； Where hr2 is the vertical height of the obstacle shielding the radar at the farthest distance, in meters; ho2 is the optical sight coverage height of the obstacle at the farthest distance, in meters; d2 is the distance from the farthest distance to the center point of the radar horizontal phase, in km; ds is the distance between the obstacle and the center point of the radar horizontal phase, in km; The vertical obstruction range at the radar position ds is [0, hr2]; Compare the minimum safe operating altitude with the maximum value of the vertical obstruction range hr2; if the minimum safe operating altitude is less than the maximum value of the vertical obstruction range hr2, then the flight procedure or high-altitude route is listed as an object to be analyzed; if the minimum safe operating altitude is greater than the maximum value of the vertical obstruction range hr2, then the flight procedure or high-altitude route is not listed as an object to be analyzed; According to the above method, all flight procedures and high-altitude routes are analyzed and judged one by one, and the analysis of flight procedures and high-altitude routes is completed.

Images