Space-based electromagnetic signal coverage rate evaluation method

Abstract

The invention discloses a space-based electromagnetic signal coverage rate evaluation method, which comprises the following steps of: establishing a power density model of a space-based electromagnetic signal based on an orbit geometrical relationship between a satellite and an antenna; based on the sensitivity of the satellite and the power density of the antenna, acquiring the capturing condition of the space-based electromagnetic signal by the satellite; calculating the effective coverage range of the satellite based on the capturing condition of the space-based electromagnetic signal by the satellite; calculating the effective coverage time of the satellite based on the effective coverage range of the satellite; and based on the detection probability of the antenna, constructing a coverage rate evaluation model of the satellite to the space-based electromagnetic signal. According to the method, the power density and the detection probability of the space-based electromagnetic signal are analyzed, the coverage rate evaluation value is calculated, and a more comprehensive theoretical basis is provided for practical application of coverage rate evaluation of the space-based signal.

Description

Technical Field

[0001] The present invention relates to satellite detection probability technology, and specifically to a method for evaluating the coverage rate of space-based electromagnetic signals. Background Art

[0002] Remote sensing satellites play an important role in modern society. Especially in civilian fields such as environmental monitoring, resource exploration, disaster management, and scientific research, remote sensing satellites have played a crucial role. In these activities, remote sensing satellites capture and process antenna signals, and have unique advantages in monitoring the atmosphere and the ocean. Compared with traditional ground observation methods, remote sensing satellites are less affected by weather, have the ability to observe all day and all weather, have a wide coverage range, and a high probability of detecting targets, and are an important data source in modern information systems.

[0003] Although satellites have significant advantages in space-based electromagnetic signal observation, there are some limitations in existing research. First, current research mainly focuses on coverage analysis in the spatial and temporal domains, and does not fully consider the influence of the energy domain and the frequency domain, which leads to insufficient comprehensive understanding of signal capture and processing. Second, existing literature pays more attention to macroscopic factors such as the instantaneous coverage range, coverage area, flight cycle, repeated reconnaissance cycle, and coverage effective time of satellites, and lacks in-depth analysis of the specific signal characteristics of space-based electromagnetic signals and their changes in different environments. In addition, existing research mostly uses idealized simulation conditions and does not fully consider background noise in the actual environment, which may affect the effectiveness and reliability of research results in practical applications.

[0004] Therefore, to solve this problem, the present invention constructs an evaluation model for the coverage rate of space-based electromagnetic signals, and calculates the coverage rate evaluation value by analyzing the power density and detection probability of space-based electromagnetic signals. This method makes up for the limitations of existing research and provides a more comprehensive theoretical basis for the practical application of the coverage rate evaluation of space-based signals. Summary of the Invention

[0005] The purpose of the present invention is to propose a method for evaluating the coverage rate of space-based electromagnetic signals to solve the problems of frequency and energy loss, environmental neglect, and ideal conditions in existing research.

[0006] The technical solution for achieving the purpose of the present invention is as follows: A method for evaluating the coverage rate of space-based electromagnetic signals, comprising the following steps:

[0007] Step 1, based on the orbital geometric relationship between the satellite and the antenna, establish a power density model of space-based electromagnetic signals;

[0008] Step 2, based on the satellite sensitivity and the power density of the antenna, obtain the capture situation of the satellite for space-based electromagnetic signals;

[0009] Step 3: Calculate the effective coverage range of the satellite based on the capture situation of the space-based electromagnetic signal by the satellite;

[0010] Step 4: Calculate the effective coverage time of the satellite based on the effective coverage range of the satellite;

[0011] Step 5: Construct an evaluation model for the coverage rate of the space-based electromagnetic signal by the satellite based on the detection probability of the antenna.

[0012] Furthermore, in Step 1: Establish a power density model of the space-based electromagnetic signal based on the orbital geometric relationship between the satellite and the antenna. The specific method is as follows:

[0013] The orbital geometric relationship between the satellite and the antenna is:

[0014]

[0015] R≈Hsecω

[0016] In the formula, ω is the angle between the line connecting the satellite and the antenna and the normal direction, is the antenna elevation angle, θ is the angle by which the line connecting the satellite and the antenna deviates from the main lobe direction of the antenna, H is the height of the satellite orbit, and R is the distance between the satellite and the antenna;

[0017] Based on the orbital geometric relationship between the satellite and the antenna, the power density S r emitted by the antenna is:

[0018]

[0019] In the formula, P t is the maximum power of the antenna; G(θ) is the spatial gain model of the antenna, which is a piecewise function related to the angle θ by which the line connecting the satellite and the antenna deviates from the main lobe direction of the antenna.

[0020] Furthermore, in Step 2: Obtain the capture situation of the space-based electromagnetic signal by the satellite based on the satellite sensitivity and the power density of the antenna. The specific method is as follows:

[0021] The power density Sr 的 emitted by the antenna has the unit of W / m 2 , take the logarithm of it to convert its unit to dBW / m 2 , and obtain the logarithm S d of the power density emitted by the antenna:

[0022]

[0023] Since Therefore Take the logarithm of it to get:

[0024] 10log(sec 2ω) = -20log(cosω)

[0025] Simplify the logarithmic power density S emitted by the antenna d :

[0026]

[0027] The situation F of the satellite's capture of space-based electromagnetic signals is as follows:

[0028]

[0029] In the formula, S d is the logarithmic power density emitted by the antenna, and S s is the satellite sensitivity, both in dBW / m 2 .

[0030] Furthermore, in step 3, based on the situation of the satellite's capture of space-based electromagnetic signals, calculate the effective coverage range of the satellite. The specific method is as follows:

[0031] Substitute the judgment situation of the satellite's capture of space-based electromagnetic signals F into the logarithmic antenna power density S d to obtain:

[0032]

[0033] Solve for the angle range Δω between the satellite-antenna connection line and the normal direction when the satellite can capture space-based electromagnetic signals, which is the effective coverage range of the satellite.

[0034] Furthermore, in step 4, based on the effective coverage range of the satellite, calculate the effective coverage time of the satellite. The specific method is as follows:

[0035] The geometric relationship of the satellite's orbital motion is:

[0036]

[0037] In the formula, α is the angle between the satellite-earth center connection line and the normal direction; ω is the angle between the satellite-antenna connection line and the normal direction, H is the height of the satellite orbit, and r is the radius of the earth;

[0038] Since sin(π - ω) = sinω, the geometric relationship of the satellite's orbital motion is simplified to:

[0039]

[0040] Substitute the satellite's effective coverage range Δω to obtain the angle range Δα between the satellite-earth center connection line and the normal direction:

[0041]

[0042] When the satellite orbits the Earth once, the effective coverage time \(t\) of the satellite for the antenna is:

[0043]

[0044] Among them, \(T\) is the operating period of the satellite.

[0045] Furthermore, in step 5, based on the detection probability of the antenna, an evaluation model for the coverage rate of the satellite for space-based electromagnetic signals is constructed. The specific method is as follows:

[0046] Based on the detection probability principle, when the satellite passes through the mission area containing the antenna each time, the detection probability \(P\) of the antenna is:

[0047] \(P = 1 - e\) -z

[0048] Among them, \(t\) is the effective coverage time of the satellite for the antenna, \(v\) s is the velocity of the sub-satellite point movement of the satellite, \(w\) is the scanning width of the satellite detector, and \(A\) is the area of the region;

[0049] Define the coverage rate evaluation \(P\) of the satellite for space-based electromagnetic signals b as:

[0050]

[0051] Among them, \(S\) d is the logarithmic power density emitted by the antenna, \(S\) s is the sensitivity of the satellite, \(T\) is the operating period of the satellite, \(\Delta\omega\) is the effective reconnaissance angle range of the satellite, \(H\) is the height of the satellite orbit, and \(r\) is the radius of the Earth.

[0052] A space-based electromagnetic signal coverage rate evaluation system implements the above-mentioned space-based electromagnetic signal coverage rate evaluation method to achieve the evaluation of the space-based electromagnetic signal coverage rate.

[0053] A computer device includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, it implements the above-mentioned space-based electromagnetic signal coverage rate evaluation method to achieve the evaluation of the space-based electromagnetic signal coverage rate.

[0054] A computer-readable storage medium stores a computer program. When the computer program is executed by a processor, it implements the above-mentioned space-based electromagnetic signal coverage rate evaluation method to achieve the evaluation of the space-based electromagnetic signal coverage rate.

[0055] Compared with the prior art, the significant advantages of the present invention are as follows: By analyzing the power density and detection probability of space-based electromagnetic signals and calculating the coverage evaluation value, this method makes up for the limitations of existing research and provides a more comprehensive theoretical basis for the practical application of the coverage evaluation of space-based signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 is a diagram of the orbital geometric relationship between a satellite and an antenna;

[0057] Figure 2 is a flowchart of a method for evaluating the coverage of space-based electromagnetic signals. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0058] In order to make the objectives, technical solutions and advantages of the present application more clear and understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0059] A method for evaluating the coverage of space-based electromagnetic signals includes the following steps:

[0060] Step 1: Based on the orbital geometric relationship between a satellite and an antenna, establish a power density model of space-based electromagnetic signals;

[0061] According to Figure 1 obtain the orbital geometric relationship of the satellite relative to the antenna:

[0062]

[0063] R≈Hsecω

[0064] where ω is the angle between the line connecting the satellite and the antenna and the normal direction, is the antenna elevation angle, θ is the angle by which the line connecting the satellite and the antenna deviates from the main lobe direction of the antenna, H is the height of the satellite orbit, and R is the distance between the satellite and the antenna.

[0065] Based on the orbital geometric relationship between a satellite and an antenna, the power density S of the antenna emission r is:

[0066]

[0067] where P t is the maximum power of the antenna; G(θ) is the spatial gain model of the antenna, which is a piecewise function related to the angle θ by which the line connecting the satellite and the antenna deviates from the main lobe direction of the antenna; ω is the angle between the line connecting the satellite and the antenna and the normal direction; is the antenna elevation angle; R is the distance between the satellite and the antenna.

[0068] Step 2: Based on the satellite sensitivity and the power density of the antenna, obtain the capture situation of the satellite for the space-based electromagnetic signal;

[0069] The power density S emitted by the antenna r has the unit of W / m 2 , take the logarithm of it, and convert its unit to dBW / m 2 , to obtain the logarithm of the power density S emitted by the antenna d :

[0070]

[0071] Since Therefore Taking the logarithm of it gives:

[0072] 10log(sec 2 ω) = -20log(cosω)

[0073] Furthermore, simplify the logarithm of the power density S emitted by the antenna d :

[0074]

[0075] The capture situation F of the satellite for the space-based electromagnetic signal is:

[0076]

[0077] In the formula, S d is the logarithm of the power density emitted by the antenna, and S s is the satellite sensitivity, and the units are both dBW / m 2 .

[0078] Step 3: Based on the capture situation of the satellite for the space-based electromagnetic signal, calculate the effective coverage range of the satellite;

[0079] Substitute the judgment situation of the capture situation F of the satellite for the space-based electromagnetic signal into the logarithm of the antenna power density S d to obtain:

[0080]

[0081] Solve for the angular range Δω between the line connecting the satellite and the antenna and the normal direction when the satellite can capture the space-based electromagnetic signal, and define this range Δω as the effective coverage range of the satellite.

[0082] Step 4: Based on the effective coverage range of the satellite, calculate the effective coverage time of the satellite;

[0083] According to Figure 1 the geometric relationship of the satellite's orbital motion is obtained as:

[0084]

[0085] In the formula, α is the angle between the line connecting the satellite and the center of the earth and the normal direction; ω is the angle between the line connecting the satellite and the antenna and the normal direction.

[0086] Since sin(π - ω) = sinω, the geometric relationship of the satellite orbital motion can be simplified as:

[0087]

[0088] Substituting the effective coverage range Δω of the satellite, the angle range Δα between the line connecting the satellite and the center of the earth and the normal direction is obtained:

[0089]

[0090] In the formula, H is the height of the satellite orbit, and r is the radius of the earth.

[0091] Therefore, when the satellite orbits the earth once, the effective coverage time of the satellite for the antenna is:

[0092]

[0093] Among them, T is the operating period of the satellite, Δω is the effective coverage range of the satellite, H is the height of the satellite orbit, and r is the radius of the earth.

[0094] Step 5: Based on the detection probability of the antenna, construct an evaluation model for the coverage rate of the satellite for space-based electromagnetic signals;

[0095] Detection can be regarded as a search method. When the detection system searches a specified area, the search methods mainly include exhaustive search, random search and other search methods. Based on the detection probability principle, when the satellite passes through the mission area containing the antenna each time, the detection probability P of the antenna is:

[0096] P = 1 - e -z

[0097] Among them, t is the effective coverage time of the satellite for the antenna, v s is the velocity of the sub-satellite point motion of the satellite, w is the scanning width of the satellite detector, and A is the area of the region.

[0098] Furthermore, define the coverage rate evaluation P of the satellite for space-based electromagnetic signals b as:

[0099]

[0100] Among them, S d is the logarithm of the power density emitted by the antenna, S sLet \(S\) be the sensitivity of the satellite, \(T\) be the operating period of the satellite, \(\Delta\omega\) be the effective reconnaissance angle range of the satellite, \(H\) be the height of the satellite orbit, and \(r\) be the radius of the Earth. The coverage rate evaluation probability \(P\). b It represents the possibility that the satellite effectively detects the antenna during each transit and thus forms an effective coverage of it. In this way, the transition is made from the single-detection probability \(P\) to the coverage rate evaluation probability \(P\). b Combines the effectiveness of the satellite detection ability, that is, only when the logarithmic power density \(S\) of the signal emitted by the antenna d exceeds the satellite sensitivity \(S\). s is it considered that the space-based electromagnetic signal is effectively covered, thus excluding a part of interference and noise.

[0101] In summary, the present invention constructs a space-based electromagnetic signal coverage rate evaluation model, and calculates the coverage rate evaluation value by analyzing the power density and detection probability of the space-based electromagnetic signal. This method makes up for the limitations of existing research and provides a more comprehensive theoretical basis for the practical application of the coverage rate evaluation of space-based signals.

[0102] Embodiment

[0103] Deploy the above-mentioned space-based electromagnetic signal coverage rate evaluation method. Users can select satellites, add detection areas, and select mission times on the deployed system, and the system will evaluate the electromagnetic signal coverage rate according to the user's input.

[0104] Taking user A as an example, this user selects satellite B: the orbit height of this satellite is 1000 km, and the sensitivity is -125 dBW / m 2 ; adds a certain area C in the southeast, and inputs the radiation characteristic parameters of the antenna in the area: the peak power is 360 kW, the elevation angle is 30°, and the antenna gain is 28.5 dB; selects the mission time from 00:00:00 on April 1, 2024 to 23:59:00 on April 1, 2024. Then the process of threat assessment for satellite B is as follows:

[0105] The first step: According to the orbital geometric relationship between the satellite and the antenna, the power density \(S_r\) of the space-based electromagnetic signal is obtained as:

[0106]

[0107] The second step: Based on the satellite sensitivity and the power density of the antenna, the capture situation \(F\) of the satellite for the space-based electromagnetic signal is obtained as:

[0108] Take the logarithm of the power density \(S_r\) of the antenna signal and convert its unit to dBW / m 2 :

[0109]

[0110]

[0111] The signal capture situation of the satellite for the antenna is as follows:

[0112]

[0113] Step 3: Calculate the effective coverage range of the satellite based on the signal capture situation of the satellite for the space-based electromagnetic signal:

[0114] S d ≥S s

[0115] That is

[0116]

[0117] Solve for the effective coverage range Δω of the satellite:

[0118] Δω = 5.54°

[0119] Step 4: Calculate the effective coverage time of the satellite based on the effective coverage range of the satellite:

[0120]

[0121] Step 5: Construct an evaluation model for the coverage rate of the satellite for the space-based electromagnetic signal based on the detection probability of the antenna:

[0122]

[0123] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0124] The above-described embodiments only represent several implementation manners of the present application. Their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A method for assessing coverage of space-based electromagnetic signals, characterized in that: The steps include: Step 1: Establish a power density model of space-based electromagnetic signals based on the orbital geometry of the satellite and the antenna; Step 2: Based on the satellite sensitivity and the power density of the antenna, the satellite captures the space-based electromagnetic signal; Step 3, based on the satellite's capture of space-based electromagnetic signals, calculate the effective coverage of the satellite; Step 4, based on the effective coverage range of the satellite, calculate the effective coverage time of the satellite; Step 5: Based on the detection probability of the antenna, a satellite coverage evaluation model for space-based electromagnetic signals is constructed.

2. The space-based electromagnetic signal coverage assessment method according to claim 1, characterized in that: Step 1: Based on the orbital geometry between the satellite and the antenna, a power density model of the space-based electromagnetic signal is established. The specific method is as follows: The orbital geometry of the satellite relative to the antenna is: R≈Hsecω Where ω is the angle between the satellite and antenna line and the normal direction, is the antenna elevation angle, θ is the angle at which the line connecting the satellite and the antenna deviates from the direction of the antenna main lobe, H is the height of the satellite orbit, and R is the distance between the satellite and the antenna; Based on the geometric relationship between the satellite and the antenna orbit, the power density S emitted by the antenna is r for: Where P t is the maximum power of the antenna; G(θ) is the spatial gain model of the antenna, which is a piecewise function related to the angle θ of the line connecting the satellite and the antenna offset from the direction of the antenna main lobe.

3. The space-based electromagnetic signal coverage assessment method according to claim 1, characterized in that: Step 2: Based on the satellite sensitivity and the power density of the antenna, obtain the satellite's capture of the space-based electromagnetic signal. The specific method is as follows: The power density S emitted by the antenna r The unit is W / m 2 , take its logarithm and convert its unit into dBW / m 2 , get the logarithm of the power density S emitted by the antenna d : because therefore Taking the logarithm of this gives: 10log(sec 2 ω)=-20log(cosω) Simplified logarithm of power density S emitted by the antenna d : The satellite captures the space-based electromagnetic signal F as follows: In the formula, S d is the logarithm of the power density emitted by the antenna, S s is the satellite sensitivity, in dBW / m 2 .

4. The space-based electromagnetic signal coverage assessment method according to claim 3, characterized in that: Step 3: Calculate the effective coverage of the satellite based on the satellite's capture of space-based electromagnetic signals. The specific method is as follows: Substitute the satellite's judgment on the capture of space-based electromagnetic signals F into the logarithm of the antenna power density S d In, we get: When the satellite is able to capture space-based electromagnetic signals, the angle range Δω between the line connecting the satellite and the antenna and the normal direction is the effective coverage range of the satellite.

5. The space-based electromagnetic signal coverage assessment method according to claim 1, characterized in that: Step 4: Calculate the effective coverage time of the satellite based on the effective coverage range of the satellite. The specific method is: The geometric relationship of satellite orbital motion is: Where α is the angle between the line connecting the satellite and the center of the earth and the normal direction; ω is the angle between the line connecting the satellite and the antenna and the normal direction; H is the height of the satellite orbit, and r is the radius of the earth; Since sin(π-ω)=sinω, the geometric relationship of satellite orbital motion is simplified to: Substituting the effective coverage range of the satellite Δω, we can obtain the angle range Δα between the line connecting the satellite and the center of the earth and the normal direction: When the satellite orbits the earth once, the effective coverage time t of the satellite to the antenna is: Where T is the satellite's operating period.

6. The space-based electromagnetic signal coverage assessment method according to claim 1, characterized in that: Step 5: Based on the detection probability of the antenna, a satellite coverage evaluation model for space-based electromagnetic signals is constructed. The specific method is as follows: Based on the principle of detection probability, each time the satellite passes through the mission area containing the antenna, the detection probability P of the antenna is: P=1-e -z in, t is the effective coverage time of the satellite to the antenna, v s is the speed of the subsatellite point, w is the scanning width of the satellite detector, and A is the area of ​​the region; Define the coverage rate of satellite to space-based electromagnetic signals P b for: Among them, S d is the logarithm of the power density emitted by the antenna, S s is the sensitivity of the satellite, T is the satellite's operating period, Δω is the satellite's effective reconnaissance angle range, H is the height of the satellite's orbit, and r is the radius of the earth.

7. A space-based electromagnetic signal coverage assessment system, characterized in that: Implement the space-based electromagnetic signal coverage assessment method described in any one of claims 1 to 6 to achieve space-based electromagnetic signal coverage assessment.

8. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the space-based electromagnetic signal coverage assessment method according to any one of claims 1 to 6 is implemented to achieve space-based electromagnetic signal coverage assessment.

9. A computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the space-based electromagnetic signal coverage assessment method according to any one of claims 1 to 6 is implemented to achieve space-based electromagnetic signal coverage assessment.

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