A performance evaluation method for bistatic ground-based planetary radar

Abstract

The present invention relates to the field of ground-based radar observation technology, and specifically to a method for evaluating the performance of a dual-base ground-based planetary radar, comprising the following steps: Step 1: Establishing a ground-based transmitting radar parameter library and calculating the equivalent isotropically radiated power of the ground-based transmitting radar; Step 2: Establishing a ground-based receiving radar parameter library and calculating the quality factor of the ground-based receiving radar system; Step 3: Establishing an asteroid target parameter library and evaluating the echo signal characteristics; Step 4: Analyzing and evaluating the operating frequency and operating mode matching of the dual-base planetary radar based on search and find; Step 5: Analyzing the timing matching capability of the dual-base planetary radar based on light travel time; Step 6: Completing the performance evaluation of the dual-base planetary radar based on a comprehensive evaluation function and determining the optimal operating state; Step 7: Establishing a normalized evaluation function and systematically evaluating feasibility. The present invention achieves joint observation by coordinating the operating modes and operating timings of the transmitting and receiving radars.

Description

Technical Field

[0001] The present invention relates to the field of ground-based radar observation technology, and in particular to a dual-base ground-based planetary radar performance evaluation method. Background Art

[0002] Ground-based radar detection relies on large-aperture antennas on the ground as transmitting and receiving antennas. It exploits the relative motion between the radar and the target and detects the time delay and Doppler shift of the return signal to achieve target detection. Ground-based radar observations of celestial bodies within the solar system can be used to map the surface topography, determine surface properties (thickness, dielectric constant, geological structure, etc.), and detect permanently shadowed areas. These applications play a unique and important role in celestial exploration. The Goldstone Solar System Radar and Arecibo Planetary Radar in the United States have achieved remarkable results in the exploration of the Moon, Mars, Venus, and asteroids.

[0003] Radar tracking data can more accurately determine the orbital trajectory of an asteroid and predict its trajectory for years into the future. Observing an asteroid with radar for less than an hour can determine its orbit more accurately than observing it for months with an optical telescope. Radar observations can reduce the uncertainty of an asteroid's position from the thousands of kilometers provided by optical observations to a few meters. The impact risk posed by a potentially hazardous asteroid can be resolved relatively quickly through radar observations, whereas with optical observations alone, it may remain uncertain for years. Relying solely on existing optical telescopes cannot achieve autonomous, rapid, and accurate assessments of hazard risks.

[0004] To meet this demand, the present invention proposes a dual-base ground-based planetary radar performance evaluation method, which realizes the dual-base ground-based radar performance evaluation by establishing ground-based transmitting radar parameters, ground-based receiving radar parameters, and asteroid target library parameters. Summary of the Invention

[0005] The purpose of the present invention is to provide a dual-base ground-based planetary radar performance evaluation method to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A method for evaluating the performance of a bistatic ground-based planetary radar comprises the following steps:

[0008] Step 1: Establish a ground-based transmitting radar parameter library and calculate the equivalent isotropic radiated power of the ground-based transmitting radar;

[0009] Step 2: Establish a ground-based receiving radar parameter library and calculate the quality factor of the ground-based receiving radar system;

[0010] Step 3: Establish an asteroid target parameter library and evaluate the echo signal characteristics;

[0011] Step 4: Analyze and evaluate the working frequency and working mode matching of the dual-base planetary ground radar based on the search;

[0012] Step 5: Analyze the timing matching capability of the dual-base planetary ground radar based on light travel time;

[0013] Step 6: Complete the performance evaluation of the bistatic planetary radar based on the comprehensive evaluation function and determine the optimal working state;

[0014] Step 7: Establish a normalized evaluation function and systematically evaluate the feasibility.

[0015] Preferably, step 1 specifically includes:

[0016] Calculate the antenna gain Gt of the ground-based transmitting radar:

[0017] (1);

[0018] In formula (1), ηt represents the antenna efficiency of ground-based transmitting radar, Dt represents the antenna aperture of ground-based transmitting radar, t is the wavelength of the ground-based radar signal;

[0019] Calculate the equivalent isotropic radiated power (EIRP) of ground-based transmitting radar:

[0020] (2);

[0021] In formula (2), Pt represents the transmitter power of the ground-based radar.

[0022] Preferably, step 2 specifically includes:

[0023] Calculate the ground-based receiving radar antenna gain Gr:

[0024] (3);

[0025] In formula (3), ηr represents the antenna efficiency of the ground-based receiving radar, Dr represents the antenna aperture of the ground-based receiving radar, r is the wavelength of the ground-based receiving radar signal;

[0026] Calculate the quality factor G / T of the ground-based receiving radar system:

[0027] (4);

[0028] In formula (4), Ts represents the noise temperature of the ground-based receiving radar system.

[0029] Preferably, step 3 specifically includes:

[0030] Calculate the radar cross section RCS of an asteroid:

[0031] (5);

[0032] In formula (5) represents the albedo coefficient, S represents the projected area of ​​the asteroid in the radar observation direction;

[0033] Calculate the spectral bandwidth B of the echo signal:

[0034] (6);

[0035] In formula (6) Indicates the target caliber, represents the observation angle, represents the spin period.

[0036] Preferably, step 4 specifically includes:

[0037] Step 4.1: Assuming that the number of ground-based transmitting radars is N, for the ground-based transmitting radar numbered n, read the radar parameter database; assuming that the number of ground-based transmitting radars is M, for the ground-based receiving radar numbered m, read the radar parameter database;

[0038] Step 4.2: Take the intersection of the operating frequency ranges of n ground-based transmitting radars and m ground-based receiving radars to determine the operating frequency set Fre0 of the bistatic radar. m-n :

[0039] (7);

[0040] In formula (7), Fre_min_t represents the minimum operating frequency of the ground-based transmitting radar, Fre_max_t represents the maximum operating frequency of the ground-based transmitting radar, I represents that n ground-based transmitting radars contain I groups of operating frequencies, and i represents the i-th group of transmitting frequencies of n ground-based transmitting radars; Fre_min_r represents the minimum operating frequency of the ground-based receiving radar, Fre_max_r represents the maximum operating frequency of the ground-based receiving radar, J represents that m ground-based transmitting radars contain J groups of operating frequencies, and j represents the j-th group of transmitting frequencies of m ground-based transmitting radars;

[0041] Step 4.3: Assumptions There are Q groups of frequencies in total. For the qth group of frequencies, the radar transmit signal mode and the radar receive signal mode are determined by looking up the table and taking the intersection to obtain the working mode set WM0 of the bistatic radar. m-n (q):

[0042] (8);

[0043] In formula (8) Indicates the radar transmission signal mode, Represents the radar receiving signal mode; for Q groups of operating frequencies, the radar transmitting signal mode and radar receiving signal mode corresponding to the qth group of frequencies are expressed as 、 , if the intersection of the two is not empty, it means the working modes match and they can work together at the qth group of frequencies;

[0044] Step 4.4: When the working mode matches is a non-empty set, and the operating frequencies and operating modes of n ground-based transmitting radars and m ground-based receiving radars are expressed as:

[0045] (9);

[0046] Assumptions 、 Each contains K groups of data, that is, n ground-based transmitting radars and m ground-based receiving radars can work together in the K-group state, which is recorded as , for which The group working frequency and working mode are recorded as 、 .

[0047] Preferably, step 5 specifically includes:

[0048] Step 5.1: Calculate the arc segment T that is visible to the asteroid's ascending trajectory by ground-based radar. m-CCC :

[0049] (10);

[0050] In formula (10), CCC represents the asteroid number, Φ 上行 represents the calculation model of the visible arc segment of the asteroid's upward trajectory, Pos_t(m) represents the site of the ground-based transmitting radar station, Pos CCC Indicates the position information of the asteroid;

[0051] Step 5.2: Calculate the arc T of the asteroid visible to the ground-based receiving radar. n-CCC :

[0052] (11);

[0053] In formula (11), Φ 下行 represents the calculation model of the downgoing visible arc of the asteroid, Pos_t(n) represents the site of the ground-based receiving radar;

[0054] Step 5.3: Determine the uplink visible arc T of the ground-based transmitting radar and the ground-based receiving radar by using the uplink and downlink signal propagation modes. 上行-CCC and the downward visible arc segment T 下行-CCC :

[0055] (12);

[0056] In formula (12) Indicates the light travel time of an asteroid;

[0057] like 、 If is not empty, the ground-based transmitting radar and the ground-based receiving radar work in a timing matching manner. 、 The larger the value, the longer the joint observation time.

[0058] Preferably, step 6 specifically includes:

[0059] Step 6.1. Calculate the echo signal power-to-noise spectral density ratio PN0:

[0060] (13);

[0061] In formula (13), L1 represents the atmospheric loss and L2 represents the pointing loss;

[0062] Step 6.2: For the first Group operating frequency and working mode 、 , the echo signal power noise spectral density is expressed as :

[0063] (14).

[0064] Preferably, step 7 specifically includes:

[0065] Step 7.1: Construct a comprehensive evaluation function based on the product of observation duration and echo signal energy:

[0066] (15);

[0067] Step 7.2, find The corresponding maximum value , expressed as :

[0068] (16);

[0069] It is thus determined that Transmitting radar and The receiving radar works in conjunction with The group state is the optimal working state suitable for observing the asteroid.

[0070] Compared with the prior art, the present invention has the following beneficial effects:

[0071] The present invention provides a dual-base ground-based planetary radar performance evaluation method. By establishing ground-based transmitting radar parameters, ground-based receiving radar parameters, and asteroid target library parameters, and utilizing dual-base ground-based radar equations and combining the value ranges of relevant parameters, the method can rapidly obtain planetary radar detection performance evaluations under different combination modes. By matching and coordinating the operating modes and timings of the transmitting and receiving radars, joint observations can be carried out. A comprehensive evaluation function is then used to complete the dual-base planetary radar performance evaluation, thereby further determining the optimal operating state for asteroid observations. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 This is a flow chart of a dual-base ground-based planetary radar performance evaluation method provided by the present invention. DETAILED DESCRIPTION

[0073] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not 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 efforts are within the scope of protection of the present invention.

[0074] Figure 1 This is a flow chart of a dual-base ground-based planetary radar performance evaluation method provided by the present invention. Figure 1 As shown, an embodiment of the present invention provides a method for evaluating the performance of a bistatic ground-based planetary radar, comprising the following steps:

[0075] Step 1: Establish a ground-based transmitting radar parameter library and calculate the equivalent isotropic radiated power of the ground-based transmitting radar;

[0076] Step 2: Establish a ground-based receiving radar parameter library and calculate the quality factor of the ground-based receiving radar system;

[0077] Step 3: Establish an asteroid target parameter library and evaluate the echo signal characteristics;

[0078] Step 4: Analyze and evaluate the working frequency and working mode matching of the dual-base planetary ground radar based on the search;

[0079] Step 5: Analyze the timing matching capability of the dual-base planetary ground radar based on light travel time;

[0080] Step 6: Complete the performance evaluation of the bistatic planetary radar based on the comprehensive evaluation function and determine the optimal working state;

[0081] Step 7: Establish a normalized evaluation function and systematically evaluate the feasibility.

[0082] The present invention provides a dual-base ground-based planetary radar performance evaluation method. By establishing ground-based transmitting radar parameters, ground-based receiving radar parameters, and asteroid target library parameters, and utilizing dual-base ground-based radar equations and combining the value ranges of relevant parameters, the method can quickly obtain planetary radar detection performance evaluations under different combination modes. By matching and coordinating the operating modes and working timings of the transmitting and receiving radars, joint observations can be carried out. The dual-base planetary radar performance evaluation is completed using a comprehensive evaluation function, thereby further determining the optimal operating state for asteroid observations.

[0083] In one embodiment of the present invention, the ground-based transmitting radar parameters mainly include:

[0084] ① Name of ground-based transmitting radar (Nat): named according to actual needs, which can be numbers, letters, or a combination of numbers and letters, such as ABCD, EF01, etc. For example: JMS stands for Jiamusi Deep Space Station, KAS stands for Kashgar Deep Space Station, CQ stands for Chongqing Compound Eye, and other radar observation equipment;

[0085] ② Ground-based transmitting radar antenna aperture (Dt): the unit is m, such as 66m, 35m, 25m, etc.;

[0086] ③ Ground-based radar station location (Pos_t): expressed in longitude (unit: °), latitude (unit: °), and altitude (unit: m) in the Earth-fixed coordinate system. For example, 20.01N 109.4W 100 means 20.01° north latitude, 109.4° west longitude, and 100m altitude.

[0087] ④ Ground-based transmitting radar operating center frequency (Fre_t): unit: MHz, such as 435MHz (UHF band), 2400MHz (S band), 5600MHz (C band), 8700MHz, (X band), 13700GHz (Ku band), etc., which can be expanded to K band, Ka band, V band, W band and higher frequency bands according to needs;

[0088] ⑤ Ground-based transmitting radar operating bandwidth (W_t): unit MHz, such as 40MHz, 100MHz, 100MHz, etc., increase according to actual status;

[0089] ⑥ Minimum operating frequency of ground-based transmitting radar (Fre_min_t): unit: MHz, determined by the operating center frequency and operating bandwidth, Fre_min_t = Fre_t -W_t / 2;

[0090] ⑦ Maximum operating frequency of ground-based transmitting radar (Fre_max_t): unit: MHz, determined by the operating center frequency and operating bandwidth, Fre_min_t = Fre_t + W_t / 2;

[0091] ⑧ Ground-based transmitting radar antenna efficiency ( η t): Determined according to the actual status of the equipment;

[0092] ⑨ Ground-based radar transmitter power (Pt): determined according to the actual status of the equipment, unit is kW;

[0093] ⑩ Wavelength of ground-based radar signal ( t):, unit is m, ;

[0094] ⑪ Radar transmit signal mode (WM_t): continuous wave (CW), pulse (PL), pulse compression (MOP), frequency agility (FA) or all (ALL), etc.;

[0095] ⑫ Ground-based transmitting radar antenna gain (Gt): determined according to the actual status of the equipment;

[0096] ⑬ Ground-based transmitting radar equivalent isotropic radiated power (EIRP): determined according to the actual status of the equipment, unit is dBW.

[0097] Step 1 specifically includes:

[0098] Calculate the antenna gain Gt of the ground-based transmitting radar:

[0099] (1);

[0100] In formula (1), ηt represents the antenna efficiency of ground-based transmitting radar, Dt represents the antenna aperture of ground-based transmitting radar, t is the wavelength of the ground-based radar signal;

[0101] Calculate the equivalent isotropic radiated power (EIRP) of ground-based transmitting radar:

[0102] (2);

[0103] In formula (2), Pt represents the transmitter power of the ground-based radar.

[0104] For example, the parameter libraries of ground-based transmitting radars named ABCD and EF01 are shown in Tables 1 and 2 below:

[0105] Table 1 Example of ABCD radar parameter library

[0106]

[0107] Table 2 Example of EF01 radar parameter library

[0108]

[0109] In one embodiment of the present invention, the ground-based transmitting radar parameters mainly include:

[0110] ① Name of the ground-based receiving radar (Nar): It is named according to actual needs and can be a combination of numbers, letters, or numbers and letters. For example, EFGC, QQ08, etc. For example, JMS stands for Jiamusi Deep Space Station, KAS stands for Kashgar Deep Space Station, CQ stands for Chongqing Space Station, FAST stands for Guizhou Space Station, SHSS stands for Shanghai Sheshan Space Station, and SHTM stands for Shanghai Tianma Space Station.

[0111] ② Ground-based receiving radar antenna aperture (Dr): unit: m, determined according to actual conditions. For example, 500, 66, 40, 35, 25, 26, etc.;

[0112] ③ Ground-based receiving radar station location (Pos_r): the expression method is the same as Pos_t;

[0113] ④ Ground-based receiving radar operating center frequency (Fre_r): unit: MHz, such as 435MHz (UHF band), 2400MHz (S band), 5600MHz (C band), 8700MHz, (X band), 13700GHz (Ku band), etc., which can be expanded to K band, Ka band, V band, W band and higher frequency bands according to needs;

[0114] ⑤ Ground-based receiving radar operating bandwidth (W_r): unit MHz, such as 40MHz, 100MHz, 100MHz, etc., increase according to actual status;

[0115] ⑥ Minimum operating frequency of ground-based receiving radar (Fre_min_r): unit: MHz, determined by the operating center frequency and operating bandwidth, Fre_min_r = Fre_r - W_r / 2;

[0116] ⑦ Maximum operating frequency of ground-based receiving radar (Fre_max_r): unit: MHz, determined by the operating center frequency and operating bandwidth, Fre_min_r = Fre_r + W_r / 2;

[0117] ⑧ Ground-based receiving radar antenna efficiency ( η r): Determined according to the actual status of the equipment;

[0118] ⑨ Wavelength of ground-based receiving radar signal ( r): unit is m, ;

[0119] ⑩Receive signal mode (WM_r): continuous wave (CW), pulse (PL), pulse compression (MOP), frequency agility (FA) or all (ALL), etc.;

[0120] ⑪ Ground-based receiving radar system noise temperature (Ts): determined according to the actual status of the equipment, unit is K;

[0121] ⑫ Ground-based receiving radar antenna gain (Gr): determined according to the actual status of the equipment;

[0122] ⑬ Quality factor of ground-based receiving radar system (G / T): determined according to the actual status of the equipment, the unit is dB / K.

[0123] Step 2 specifically includes:

[0124] Calculate the ground-based receiving radar antenna gain Gr:

[0125] (3);

[0126] In formula (3), ηr represents the antenna efficiency of the ground-based receiving radar, Dr represents the antenna aperture of the ground-based receiving radar, r is the wavelength of the ground-based receiving radar signal;

[0127] Calculate the quality factor G / T of the ground-based receiving radar system:

[0128] (4);

[0129] In formula (4), Ts represents the noise temperature of the ground-based receiving radar system.

[0130] For example, the parameter libraries of ground-based receiving radars named EFGC and QQ08 are shown in Tables 3 and 4 below:

[0131] Table 3 Example of EFGC radar parameter library

[0132]

[0133] Table 4 Example of QQ08 radar parameter library

[0134]

[0135] In one embodiment of the present invention, the asteroid target parameters mainly include:

[0136] ① Name of the asteroid (Nam);

[0137] ② Target caliber (D): The unit is meter, for example: 1000, 500, 100, 50, etc.;

[0138] ③ Distance (R): Determined according to the actual situation, unit is m;

[0139] ④ Spin period (P): can be determined according to the actual state, unit is s;

[0140] ⑤Albedo coefficient ( ): Determined according to the actual state, the value is between 0 and 1;

[0141] ⑥ Radar Cross Section (RCS): unit is m 2 , determined according to the actual state of the asteroid;

[0142] ⑦ Spectral bandwidth of the echo signal (B): The unit is Hz and is determined according to the actual state of the asteroid;

[0143] ⑧Light travel time ( ): unit is s, , is the speed of light;

[0144] ⑨ Asteroid position (Pos): It is expressed in declination (unit: °) and right ascension (unit: °) in the geocentric celestial coordinate system. For example, 20.01N 109.4W means the declination is 20.01° north latitude and the right ascension is 109.4° west longitude.

[0145] Step 3 specifically includes:

[0146] Calculate the radar cross section RCS of an asteroid:

[0147] (5);

[0148] In formula (5) represents the albedo coefficient, S represents the projected area of ​​the asteroid in the radar observation direction;

[0149] Calculate the spectral bandwidth B of the echo signal:

[0150] (6);

[0151] In formula (6) Indicates the target caliber, represents the observation angle, represents the spin period.

[0152] For example, the asteroid target parameter library including asteroids such as 2024YR4 and 2016HO3 is shown in Table 5 below.

[0153] Table 5 Examples of asteroid target parameter libraries

[0154]

[0155] Compared with traditional bistatic radars, bistatic planetary radars are usually composed of various transmitting radars and receiving radars distributed globally, and there are significant differences in their technical parameters. In addition, there are a large number of various transmitting radars and receiving radars distributed globally. The composition of a bistatic planetary radar requires ensuring that the various technical parameters of the transmitting radar and the receiving radar match. The present invention proposes a bistatic planetary radar operating frequency and operating mode matching analysis and evaluation method based on search and find to ensure that the operating modes of the transmitting radar and the receiving radar match and coordinate, so that joint observations can be carried out. In one embodiment of the present invention, step 4 specifically includes:

[0156] Step 4.1: Assuming that the number of ground-based transmitting radars is N, for the ground-based transmitting radar numbered n, read the radar parameter database; assuming that the number of ground-based transmitting radars is M, for the ground-based receiving radar numbered m, read the radar parameter database;

[0157] Step 4.2: Take the intersection of the operating frequency ranges of n ground-based transmitting radars and m ground-based receiving radars to determine the operating frequency set Fre0 of the bistatic radar. m-n :

[0158] (7);

[0159] In formula (7), Fre_min_t represents the minimum operating frequency of the ground-based transmitting radar, Fre_max_t represents the maximum operating frequency of the ground-based transmitting radar, I represents that n ground-based transmitting radars contain I groups of operating frequencies, and i represents the i-th group of transmitting frequencies of n ground-based transmitting radars; Fre_min_r represents the minimum operating frequency of the ground-based receiving radar, Fre_max_r represents the maximum operating frequency of the ground-based receiving radar, J represents that m ground-based transmitting radars contain J groups of operating frequencies, and j represents the j-th group of transmitting frequencies of m ground-based transmitting radars;

[0160] Step 4.3: Assumptions There are Q groups of frequencies in total. For the qth group of frequencies, the radar transmit signal mode and the radar receive signal mode are determined by looking up the table and taking the intersection to obtain the working mode set WM0 of the bistatic radar. m-n (q):

[0161] (8);

[0162] In formula (8) Indicates the radar transmission signal mode, Represents the radar receiving signal mode; for Q groups of operating frequencies, the radar transmitting signal mode and radar receiving signal mode corresponding to the qth group of frequencies are expressed as 、 , if the intersection of the two is not empty, it means the working modes match and they can work together at the qth group of frequencies;

[0163] Step 4.4: When the working mode matches is a non-empty set, and the operating frequencies and operating modes of n ground-based transmitting radars and m ground-based receiving radars are expressed as:

[0164] (9);

[0165] Assumptions 、 Each contains K groups of data, that is, n ground-based transmitting radars and m ground-based receiving radars can work together in the K-group state, which is recorded as , for which The group working frequency and working mode are recorded as 、 .

[0166] Traditional bistatic radars are mainly used for close-range targets, with a detection range of hundreds of kilometers to tens of thousands of kilometers. However, the target distance detected by ground-based planetary radars may reach tens of millions of kilometers, billions of kilometers, or even hundreds of billions of kilometers. Since the light travel time of signal propagation is very large, its impact cannot be ignored, and its impact on bistatic planetary radars needs to be considered. Due to factors such as the rotation of the earth, there is a difference between the visible arc segment of the transmitting radar and the visible arc segment of the receiving radar, and observability can only be guaranteed when the operating timing of the transmitting radar and the receiving radar are matched. In one embodiment of the present invention, step 5 specifically includes:

[0167] Step 5.1: Calculate the arc segment T that is visible to the asteroid's ascending trajectory by ground-based radar. m-CCC :

[0168] (10);

[0169] In formula (10), CCC represents the asteroid number, Φ 上行 represents the calculation model of the visible arc segment of the asteroid's upward trajectory, Pos_t(m) represents the site of the ground-based transmitting radar station, Pos CCC Indicates the position information of the asteroid;

[0170] Step 5.2: Calculate the arc T of the asteroid visible to the ground-based receiving radar. n-CCC :

[0171] (11);

[0172] In formula (11), Φ 下行 represents the calculation model of the visible arc segment of the asteroid's downward trajectory, Pos_t(n) represents the site of the ground-based receiving radar station; the calculation methods and processes related to equations (10) and (11) can be determined by using orbital dynamics, time and coordinate transformation relationships, etc., which are basic knowledge and will not be introduced in detail in this invention;

[0173] Step 5.3: Determine the uplink visible arc T of the ground-based transmitting radar and the ground-based receiving radar by using the uplink and downlink signal propagation modes. 上行-CCC and the downward visible arc segment T 下行-CCC :

[0174] (12);

[0175] In formula (12) Indicates the light travel time of an asteroid;

[0176] like 、 If is not empty, the ground-based transmitting radar and the ground-based receiving radar work in a timing matching manner. 、 The larger the value, the longer the joint observation time.

[0177] Furthermore, in one embodiment of the present invention, step 6 specifically includes:

[0178] Step 6.1. Calculate the echo signal power-to-noise spectral density ratio PN0:

[0179] (13);

[0180] In formula (13), L1 represents the atmospheric loss and L2 represents the pointing loss;

[0181] Step 6.2: For the first Group operating frequency and working mode 、 , the echo signal power noise spectral density is expressed as :

[0182] (14).

[0183] Furthermore, in one embodiment of the present invention, step 7 specifically includes:

[0184] Step 7.1: Construct a comprehensive evaluation function based on the product of observation duration and echo signal energy:

[0185] (15);

[0186] Step 7.2, find The corresponding maximum value , expressed as :

[0187] (16);

[0188] It is thus determined that Transmitting radar and The receiving radar works in conjunction with The group state is the optimal working state suitable for observing the asteroid.

[0189] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for evaluating the performance of a bistatic ground-based planetary radar, characterized in that: The following steps are involved: Step 1: Establish a ground-based transmitting radar parameter library and calculate the equivalent isotropic radiated power of the ground-based transmitting radar; Step 2: Establish a ground-based receiving radar parameter library and calculate the quality factor of the ground-based receiving radar system; Step 3: Establish an asteroid target parameter library and evaluate the echo signal characteristics; Step 4: Analyze and evaluate the working frequency and working mode matching of the bistatic planetary radar based on the search; Step 5: Analyze the timing matching capability of the bistatic planetary radar based on light travel time; Step 6: Complete the performance evaluation of the bistatic planetary radar based on the comprehensive evaluation function and determine the optimal working state; Step 5 specifically includes: Step 5.1: Calculate the arc segment T that is visible to the asteroid's ascending trajectory by ground-based radar. m-CCC : （10）； In formula (10), CCC represents the asteroid number, Φ 上行 represents the calculation model of the visible arc segment of the asteroid's upward trajectory, Pos_t(m) represents the site of the ground-based transmitting radar station, Pos CCC Indicates the position information of the asteroid; Step 5.2: Calculate the arc T of the asteroid visible to the ground-based receiving radar. n-CCC : （11）； In formula (11), Φ 下行 represents the calculation model of the downgoing visible arc of the asteroid, Pos_t(n) represents the site of the ground-based receiving radar; Step 5.3: Determine the uplink visible arc of n ground-based transmitting radar and m ground-based receiving radar by uplink and downlink signal propagation mode. and the downward visible arc : （12）； In formula (12) Indicates the light travel time of an asteroid; like 、 If is not empty, the ground-based transmitting radar and the ground-based receiving radar work in a timing matching manner. 、 The larger the value, the longer the joint observation time.

2. A method for evaluating the performance of a bistatic ground-based planetary radar according to claim 1, characterized in that: Step 1 specifically includes: Calculate the antenna gain Gt of the ground-based transmitting radar: （1）； In formula (1), ηt represents the antenna efficiency of ground-based transmitting radar, Dt represents the antenna aperture of ground-based transmitting radar, t is the wavelength of the ground-based radar signal; Calculate the equivalent isotropic radiated power (EIRP) of ground-based transmitting radar: （2）； In formula (2), Pt represents the transmitter power of the ground-based radar.

3. The method for evaluating the performance of a bistatic ground-based planetary radar according to claim 2, wherein: Step 2 specifically includes: Calculate the ground-based receiving radar antenna gain Gr: （3）； In formula (3), ηr represents the antenna efficiency of the ground-based receiving radar, Dr represents the antenna aperture of the ground-based receiving radar, r is the wavelength of the ground-based receiving radar signal; Calculate the quality factor G / T of the ground-based receiving radar system: （4）； In formula (4), Ts represents the noise temperature of the ground-based receiving radar system.

4. The method for evaluating the performance of a bistatic ground-based planetary radar according to claim 3, wherein: Step 3 specifically includes: Calculate the radar cross section RCS of an asteroid: （5）； In formula (5) represents the albedo coefficient, S represents the projected area of ​​the asteroid in the radar observation direction; Calculate the spectral bandwidth B of the echo signal: （6）； In formula (6) Indicates the target caliber, represents the observation angle, represents the spin period.

5. The method for evaluating the performance of a bistatic ground-based planetary radar according to claim 4, wherein: Step 4 specifically includes: Step 4.1: Assuming that the number of ground-based transmitting radars is N, for the ground-based transmitting radar numbered n, read the radar parameter database; assuming that the number of ground-based transmitting radars is M, for the ground-based receiving radar numbered m, read the radar parameter database; Step 4.2: Take the intersection of the operating frequency ranges of n ground-based transmitting radars and m ground-based receiving radars to determine the operating frequency set Fre0 of the bistatic radar. m-n : （7）； In formula (7), Fre_min_t represents the minimum operating frequency of the ground-based transmitting radar, Fre_max_t represents the maximum operating frequency of the ground-based transmitting radar, I represents that n ground-based transmitting radars contain I groups of operating frequencies, and i represents the i-th group of transmitting frequencies of n ground-based transmitting radars; Fre_min_r represents the minimum operating frequency of the ground-based receiving radar, Fre_max_r represents the maximum operating frequency of the ground-based receiving radar, J represents that m ground-based receiving radars contain J groups of operating frequencies, and j represents the j-th group of transmitting frequencies of m ground-based receiving radars; Step 4.3: Assumptions There are Q groups of frequencies in total. For the qth group of frequencies, the radar transmit signal mode and the radar receive signal mode are determined by looking up the table and taking the intersection to obtain the working mode set WM0 of the bistatic radar. m-n (q): （8）； In formula (8) Indicates the radar transmission signal mode, Represents the radar receiving signal mode; for Q groups of operating frequencies, the radar transmitting signal mode and radar receiving signal mode corresponding to the qth group of frequencies are expressed as 、 , if the intersection of the two is not empty, it means the working modes match and they can work together at the qth group of frequencies; Step 4.4: When the working mode matches is a non-empty set, and the compatible operating frequencies of n ground-based transmitting radars and m ground-based receiving radars are and compatible working modes Expressed as: （9）； Assumptions 、 Each contains K groups of data, that is, n ground-based transmitting radars and m ground-based receiving radars can work together in the K-group state, which is recorded as , for which The group working frequency and working mode are recorded as 、 .

6. A method for evaluating the performance of a bistatic ground-based planetary radar according to claim 5, characterized in that: Step 6 specifically includes: Step 6.1, calculate the echo signal power noise spectral density PN0: （13）； In formula (13), L1 represents the atmospheric loss and L2 represents the pointing loss; Step 6.2: For the first Group operating frequency and working mode 、 , the echo signal power noise spectral density is expressed as : （14）。 7. A method for evaluating the performance of a bistatic ground-based planetary radar according to claim 6, characterized in that: Step 6 also includes: Step 6.3: Construct a comprehensive evaluation function based on the observation duration and echo signal power noise spectral density: （15）； Step 6.4, find The corresponding maximum value , expressed as : （16）； It is thus determined that Transmitting radar and The receiving radar works in conjunction with The group state is the optimal working state suitable for observing the asteroid.

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