Method and system for evaluating typhoon detection effectiveness of satellite-borne rain detection radar in orbit

Abstract

The invention provides a method and system for in-orbit evaluation of typhoon detection effectiveness of a satellite-borne rain detection radar, and the method comprises the steps: S1, obtaining a central position parameter of a to-be-detected typhoon, and obtaining a dynamic parameter of a satellite, and a detection angle range and a scanning orbit swath of the satellite-borne rain detection radar; s2, calculating the position and speed of the sub-satellite point of the satellite in the geocentric coordinate system at the current moment according to the obtained parameters, and forming a position connecting line between the sub-satellite point of the satellite and the typhoon position; s3, calculating the distance and the included angle of the position connecting line at the current moment; s4, according to the distance and the included angle of the position connecting line, the position connecting line is projected to the cross-rail scanning direction of the satellite-borne rain detection radar, and a projection distance is obtained; and S5, by comparing the projection distance with the scanning orbit swath of the spaceborne rain detection radar, evaluating the effectiveness of the spaceborne rain detection radar in detecting the typhoon to be detected. According to the method, the effectiveness of on-orbit typhoon observation of the satellite-borne rain-measuring radar is evaluated.

Description

Technical Field

[0001] The present invention relates to the research field of on-orbit evaluation of the detection ability of spaceborne rain radar for extreme weather events. Specifically, it relates to a method and system for on-orbit evaluation of the effectiveness of spaceborne rain radar in detecting typhoons. Background Art

[0002] The western Pacific Ocean is one of the high-frequency regions for tropical cyclones globally. The typhoon activities in this region have a profound impact on the weather and climate of countries in the East Asian region. Typhoon weather brings secondary disasters, such as strong winds and heavy rains, often causing extreme meteorological disasters in local areas, seriously threatening people's lives and property safety and causing great economic losses to the country. Timely and accurate forecasting and observation of the intensity and path of typhoon activities are the most effective means to prevent and reduce their impacts.

[0003] A typhoon refers to a strong cyclonic vortex generated over the tropical or subtropical ocean surface with a warm core structure. Due to its specific activity area, our understanding of it is not deep enough due to lack of observations. By using the visible and infrared remote sensing detection instruments carried on geostationary satellites, the top of the typhoon cloud system can be effectively observed, the appearance of the typhoon cloud system can be understood, and its activity path can be continuously monitored and warned. However, the ability to depict the details of other weather systems under the typhoon cloud system is limited, and this aspect needs to be supplemented by using the microwave remote sensing instruments carried on polar-orbiting satellites. China's first precipitation measurement satellite has been successfully launched. The Fengyun-3 precipitation satellite combines the collaborative observations of spaceborne active and passive microwave payloads, such as precipitation measurement radar and microwave imager, and ground-based weather radar, and uses the fused observation data to detect the atmosphere, cloud, and precipitation structures in the observation area, improving the monitoring and forecasting ability for extreme disaster weather such as typhoons.

[0004] The spaceborne rain radar is carried on the precipitation satellite and operates in a low-inclination non-sun-synchronous inclined orbit. Although it can provide features such as the three-dimensional precipitation structure of the typhoon system, the scanning swath of the detection instrument is limited, and the imaging swath is smaller compared to the instruments carried on geostationary satellites. Sometimes, satellite maneuvers are needed to increase the effective observation range for auxiliary detection. However, the process from the satellite receiving the maneuver command to the attitude being in place is complex, time-consuming, and costly. Therefore, before taking actions, it is necessary to verify the necessity of the maneuver to minimize the resource consumption of the entire satellite. During the process of the spaceborne rain radar observing the typhoon system, for some situations where it is impossible to determine whether the typhoon position is within the effective detection area of the rain radar, the most common processing method is to transmit the satellite state to the ground. The ground analyzes and judges the current state, issues a maneuver command, and after the satellite receives the command, it starts to act until the attitude is in place and then effectively observes the typhoon to be measured.

[0005] The Chinese patent document with the publication number CN118393611A discloses a precipitation estimation method, device, terminal device and medium based on a rain-measuring radar. The method includes obtaining first radar data and second radar data; clustering the first radar data to obtain a first clustering result and determining a first data state, and clustering the second radar data to obtain a second clustering result and determining a second data state; under the condition that the first data state and the second data state meet the requirements, updating a first precipitation estimation model according to the first radar data to obtain a third precipitation estimation model, and updating a second precipitation estimation model according to the second radar data to obtain a fourth precipitation estimation model; obtaining third radar data and fourth radar data, estimating the third radar data according to the third precipitation estimation model to obtain a first precipitation result; estimating the fourth radar data according to the fourth precipitation estimation model to obtain a second precipitation result; and performing data fusion on the first precipitation result and the second precipitation result to obtain a target precipitation result. This method uses multiple radars to predict precipitation, but the effectiveness of the prediction cannot be confirmed.

[0006] Considering that the on-orbit data processing technology is becoming increasingly mature, which can shorten the remote sensing data processing link and significantly improve the data application efficiency. Therefore, based on the pre-judgment of the relative positions of the satellite and the typhoon to be measured, it is possible to roughly determine whether the typhoon to be measured is in the effective observation area of the rain-measuring radar, ensure the necessary judgment before satellite maneuver on-orbit. If it is determined that the satellite can effectively detect the typhoon to be measured at this time, the satellite will perform a maneuver, reducing satellite resource consumption and increasing the probability of effectively detecting extreme weather events such as typhoons. Therefore, it is necessary to propose a method and system for on-orbit evaluating the effectiveness of spaceborne rain-measuring radar in detecting typhoons, ensuring to improve the effective detection ability of the rain-measuring radar for extreme weather events and broadening the breadth of on-orbit data processing and application fields. Summary of the Invention

[0007] Aiming at the deficiencies in the prior art, the purpose of the present invention is to provide a method and system for on-orbit evaluating the effectiveness of spaceborne rain-measuring radar in detecting typhoons.

[0008] According to a method for on-orbit evaluating the effectiveness of spaceborne rain-measuring radar in detecting typhoons provided by the present invention, it includes:

[0009] Step S1: Obtain the central position parameters of the typhoon to be detected, and at the same time obtain the dynamic parameters of the satellite, as well as the detection angle range and scanning track swath of the spaceborne rain-measuring radar;

[0010] Step S2: According to the obtained parameters, calculate the position and velocity of the satellite sub-satellite point in the geocentric coordinate system at the current moment, and form a position connection line between the satellite sub-satellite point and the typhoon position;

[0011] Step S3: According to the position of the satellite sub-satellite point and the central position of the typhoon to be detected, calculate the distance and included angle of the position connection line at the current moment;

[0012] Step S4: According to the distance and angle of the position connection line, project the position connection line onto the cross-track scanning direction of the spaceborne rain radar to obtain the projected distance;

[0013] Step S5: Evaluate the effectiveness of the spaceborne rain radar in detecting the typhoon to be detected by comparing the projected distance with the scanning track swath of the spaceborne rain radar.

[0014] Preferably, the step S1 includes:

[0015] Obtain the satellite position, satellite velocity and satellite attitude parameters according to the satellite platform working state parameters, and obtain the detection angle range and scanning track swath of the spaceborne rain radar according to the rain radar working state parameters;

[0016] The position parameter of the typhoon to be measured at the current moment is the longitude and latitude parameter of the typhoon center position.

[0017] Preferably, the step S2 includes:

[0018] Step S2.1: When the spaceborne rain radar is in the on-orbit working state, convert the initial detection visual axis of the radar to the detection wave position visual axis through the payload mounting matrix and the coordinate system transformation matrix, and obtain the visual vector according to the satellite sub-satellite point detection angle;

[0019] Step S2.2: By interpolating the multi-period satellite velocity, satellite position and satellite attitude, calculate the intersection point of the visual vector and the earth's surface to obtain the position and velocity of the satellite sub-satellite point in the geocentric coordinate system at the current moment;

[0020] Step S2.3: Connect the position of the satellite sub-satellite point and the typhoon to form a position connection line.

[0021] Preferably, the step S3 includes:

[0022] Step S3.1: Convert the longitude and latitude of the typhoon center to be measured to obtain the coordinates of the typhoon center to be measured in the geocentric coordinate system. The calculation formula is as follows:

[0023]

[0024] In the formula, (x t , y t , z t ) represents the coordinates of the typhoon center to be measured in the geocentric coordinate system, represents the latitude and longitude coordinates of the typhoon center to be measured, and R e represents the radius of the earth;

[0025] Step S3.2: Calculate the position connection line distance. The calculation formula is as follows:

[0026]

[0027] In the formula, d represents the connection distance, and (x s , y s , z s ) represents the coordinates of the satellite's sub-satellite point;

[0028] Step S3.3: Calculate the angle between the satellite velocity vector at the current moment and the position connection line according to the coordinates of the satellite's sub-satellite point, the coordinates of the center position of the typhoon to be measured, the position connection distance, and the satellite velocity vector at the current moment. The calculation formula is as follows:

[0029]

[0030] In the formula, θ represents the angle between the satellite velocity vector at the current moment and the position connection line, and (v x , v y , v z ) represents the satellite velocity vector at the current moment.

[0031] Preferably, the step S4 includes:

[0032] According to the position connection distance and the angle θ, project the position connection line in the cross-track scanning direction of the spaceborne rain radar to obtain the projection distance of the position connection line in the radar cross-track scanning direction at the current moment. The calculation formula is as follows:

[0033] d ⊥ = d×sinθ

[0034]

[0035] In the formula, d ⊥ represents the projection distance of the position connection line in the cross-track scanning direction of the spaceborne rain radar at the current moment.

[0036] Preferably, the step S5 includes:

[0037] Step S5.1: Compare the projection distance d ⊥ of the position connection line in the cross-track scanning direction of the spaceborne rain radar at the current moment with the swath of the spaceborne rain radar scanning orbit;

[0038] Step S5.2: Evaluate the effectiveness of the spaceborne rain radar in detecting the typhoon to be detected. If d ⊥ is greater than the swath of the spaceborne rain radar scanning orbit, the spaceborne rain radar cannot effectively observe the typhoon to be detected in the current working mode of the spaceborne rain radar. Command the satellite to maneuver to increase the effective observation range;

[0039] If d ⊥ is less than the swath of the spaceborne rain radar scanning orbit, the current spaceborne rain radar can effectively observe the typhoon. Command the spaceborne rain radar to continue the observation.

[0040] A system for on-orbit evaluation of the effectiveness of spaceborne rain radar in detecting typhoons provided by the present invention includes:

[0041] Module M1: Obtain the central position parameters of the typhoon to be detected, and at the same time obtain the dynamic parameters of the satellite and the detection angle range and scanning orbit swath of the spaceborne rain radar;

[0042] Module M2: According to the obtained parameters, calculate the position and velocity of the satellite sub-satellite point in the geocentric coordinate system at the current moment, and form a position connection line between the satellite sub-satellite point and the typhoon position;

[0043] Module M3: According to the position of the satellite sub-satellite point and the central position of the typhoon to be detected, calculate the distance and included angle of the position connection line at the current moment;

[0044] Module M4: According to the distance and included angle of the position connection line, project the position connection line onto the cross-track scanning direction of the spaceborne rain radar to obtain the projected distance;

[0045] Module M5: By comparing the projected distance with the scanning orbit swath of the spaceborne rain radar, evaluate the effectiveness of the spaceborne rain radar in detecting the typhoon to be detected.

[0046] Preferably, the module M1 includes:

[0047] Obtain the satellite position, satellite velocity and satellite attitude parameters according to the satellite platform working state parameters, and obtain the detection angle range and scanning orbit swath of the spaceborne rain radar according to the rain radar working state parameters;

[0048] The position parameters of the typhoon to be measured at the current moment are the longitude and latitude parameters of the typhoon center position;

[0049] The module M2 includes:

[0050] Module M2.1: When the spaceborne rain radar is in the on-orbit working state, convert the initial detection visual axis of the radar to the detection wave position visual axis through the payload installation matrix and the coordinate system conversion matrix, and obtain the visual vector according to the detection angle of the satellite sub-satellite point;

[0051] Module M2.2: By interpolating the satellite velocity, satellite position and satellite attitude in multiple periods, calculate the intersection point of the visual vector and the earth's surface to obtain the position and velocity of the satellite sub-satellite point in the geocentric coordinate system at the current moment;

[0052] Module M2.3: Connect the position of the satellite sub-satellite point and the typhoon to form a position connection line.

[0053] Preferably, the module M3 includes:

[0054] Module M3.1: Convert the longitude and latitude of the typhoon center to be measured to obtain the coordinates of the typhoon center to be measured in the geocentric coordinate system. The calculation formula is as follows:

[0055]

[0056] In the formula, (x t , y t , z t ) represents the coordinates of the typhoon center to be measured in the geocentric coordinate system, represents the latitude and longitude coordinates of the typhoon center to be measured, and R e represents the radius of the earth;

[0057] Module M3.2: Calculate the distance of the position connection line. The calculation formula is as follows:

[0058]

[0059] In the formula, d represents the distance of the connection line, and (x s , y s , z s ) represents the coordinates of the satellite sub-satellite point;

[0060] Module M3.3: Calculate the angle between the satellite velocity vector at the current moment and the position connection line according to the coordinates of the satellite sub-satellite point, the position coordinates of the typhoon center to be measured, the distance of the position connection line, and the satellite velocity vector at the current moment. The calculation formula is as follows:

[0061]

[0062] In the formula, θ represents the angle between the satellite velocity vector at the current moment and the position connection line, and (v x , v y , v z ) represents the satellite velocity vector at the current moment;

[0063] The module M4 includes:

[0064] According to the distance of the position connection line and the angle θ, project the position connection line in the cross-track scanning direction of the spaceborne rain radar to obtain the projection distance of the position connection line in the radar cross-track scanning direction at the current moment. The calculation formula is as follows:

[0065] d ⊥ = d × sinθ

[0066]

[0067] In the formula, d ⊥ represents the projection distance of the position connection line in the cross-track scanning direction of the spaceborne rain radar at the current moment.

[0068] Preferably, the module M5 includes:

[0069] Module M5.1: Let the projection distance d of the position connection line at the current moment in the cross-track scanning direction of the spaceborne rain radar ⊥ be compared with the scanning track swath of the spaceborne rain radar;

[0070] Module M5.2: Evaluate the effectiveness of the spaceborne rain radar in detecting the typhoon to be detected. If d ⊥ is greater than the scanning track swath of the spaceborne rain radar, then in the current working mode of the spaceborne rain radar, it is impossible to effectively observe the typhoon to be detected. Let the satellite maneuver to increase the effective observation range;

[0071] If d ⊥ is less than the scanning track swath of the spaceborne rain radar, then the current spaceborne rain radar can effectively observe the typhoon. Let the spaceborne rain radar continue to observe.

[0072] Compared with the prior art, the present invention has the following beneficial effects:

[0073] 1. The present invention realizes the on-orbit evaluation of the effectiveness of the spaceborne rain radar in observing typhoons by comparing the projection distance of the connection line between the satellite sub-satellite point and the typhoon to be detected at the current moment in the cross-track direction of the spaceborne rain radar and the scanning track swath of the spaceborne rain radar. Compared with the existing evaluation methods, most of the existing methods transmit the on-orbit working state of the satellite to the ground, and after ground analysis and judgment, evaluate the necessity of the satellite to maneuver to observe the typhoon to be detected. According to the ground evaluation result, a maneuvering instruction is sent to the satellite, and the satellite starts to act after receiving the instruction until the attitude is in place to observe the typhoon. This method has the defects of a long space-ground data processing link, making it difficult to have real-time monitoring of typhoon activities, resulting in the unreasonable consumption of satellite resources;

[0074] 2. The present invention is used in the research field of on-orbit evaluation of the ability of spaceborne rain radars to detect extreme weather events, and is an indispensable technical means for pre-judging and identifying before satellite maneuvering detection;

[0075] 3. In the present invention, according to the relative relationship between the projected distance of the connection line between the satellite sub-satellite point and the typhoon at the current moment and the scanning track swath of the rain radar, that is, the relative position between the satellite and the typhoon to be detected, data processing is directly performed on the satellite and the necessity of satellite maneuvering is judged. Shorten the space-ground processing link of remote sensing data, ensure the effectiveness of satellite maneuvering for observing the typhoon to be detected, and provide new ideas and new methods for the spaceborne rain radar to detect typhoon activities and the three-dimensional precipitation structure and other characteristics of the typhoon system. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] By reading the following detailed description of the non-limiting embodiments with reference to the accompanying drawings, other features, objects and advantages of the present invention will become more apparent:

[0077] Figure 1Flow chart of a method for on-orbit evaluation of the effectiveness of spaceborne rain radar in detecting typhoons according to the present invention;

[0078] Figure 2 Schematic flow diagram of the method of Embodiment 1 of the present invention;

[0079] Figure 3 Schematic diagram showing the relationship between the projection distance of the line connecting the satellite sub-satellite point and the typhoon in the cross-track direction of the rain radar and the scan track swath in the present invention. Detailed implementation manners

[0080] The present invention will be described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several changes and improvements can still be made. These all belong to the protection scope of the present invention.

[0081] A method for on-orbit evaluation of the effectiveness of spaceborne rain radar in detecting typhoons provided by the present invention includes:

[0082] Step S1: Obtain the central position parameters of the typhoon to be detected, and at the same time obtain the dynamic parameters of the satellite and the detection angle range and scan track swath of the spaceborne rain radar;

[0083] Step S2: According to the obtained parameters, calculate the position and velocity of the satellite sub-satellite point in the geocentric coordinate system at the current moment, and form a position connection line between the satellite sub-satellite point and the typhoon position;

[0084] Step S3: According to the position of the satellite sub-satellite point and the central position of the typhoon to be detected, calculate the distance and angle of the position connection line at the current moment;

[0085] Step S4: According to the distance and angle of the position connection line, project the position connection line onto the cross-track scanning direction of the spaceborne rain radar to obtain the projection distance;

[0086] Step S5: By comparing the projection distance with the scan track swath of the spaceborne rain radar, evaluate the effectiveness of the spaceborne rain radar in detecting the typhoon to be detected.

[0087] Specifically, the step S1 includes:

[0088] Obtain the satellite position, satellite velocity and satellite attitude parameters according to the satellite platform working state parameters, and obtain the detection angle range and scan track swath of the spaceborne rain radar according to the rain radar working state parameters;

[0089] The position parameters of the typhoon to be detected at the current moment are the longitude and latitude parameters of the typhoon center position.

[0090] Specifically, the step S2 includes:

[0091] Step S2.1: When the spaceborne rain radar is in the on-orbit working state, the initial detection visual axis of the radar is converted to the detection wave position visual axis through the payload mounting matrix and the coordinate system transformation matrix, and the visual vector is obtained according to the satellite sub-satellite point detection angle;

[0092] Step S2.2: By interpolating the multi-period satellite velocity, satellite position and satellite attitude, calculate the intersection point of the visual vector and the earth's surface, and obtain the position and velocity of the satellite sub-satellite point in the geocentric coordinate system at the current moment;

[0093] Step S2.3: Connect the position of the satellite sub-satellite point and the typhoon to form a position connection line.

[0094] Specifically, the said step S3 includes:

[0095] Step S3.1: Obtain the coordinates of the center of the typhoon to be measured in the geocentric coordinate system through the conversion of the longitude and latitude of the center of the typhoon to be measured. The calculation formula is as follows:

[0096]

[0097]

[0098] In the formula, (x t , y t , z t ) represents the coordinates of the center of the typhoon to be measured in the geocentric coordinate system, represents the latitude and longitude coordinates of the center of the typhoon to be measured, and R e represents the radius of the earth;

[0099] Step S3.2: Calculate the distance of the position connection line. The calculation formula is as follows:

[0100]

[0101] In the formula, d represents the connection line distance, and (x s , y s , z s ) represents the coordinates of the satellite sub-satellite point;

[0102] Step S3.3: According to the coordinates of the satellite sub-satellite point, the position coordinates of the center of the typhoon to be measured, the distance of the position connection line, and the satellite velocity vector at the current moment, calculate the angle between the satellite velocity vector and the position connection line at the current moment. The calculation formula is as follows:

[0103]

[0104] In the formula, θ represents the angle between the satellite velocity vector and the position connection line at the current moment, and (v x , v y , v z)Represents the satellite velocity vector at the current moment.

[0105] Specifically, the step S4 includes:

[0106] According to the position connection distance and the angle θ, project the position connection in the cross-track scanning direction of the spaceborne rain radar to obtain the projection distance of the position connection in the radar cross-track scanning direction at the current moment. The calculation formula is as follows:

[0107] d ⊥ = d × sinθ

[0108]

[0109] In the formula, d ⊥ represents the projection distance of the position connection in the cross-track scanning direction of the spaceborne rain radar at the current moment.

[0110] Specifically, the step S5 includes:

[0111] Step S5.1: Compare the projection distance d ⊥ of the position connection in the cross-track scanning direction of the spaceborne rain radar at the current moment with the scanning track swath of the spaceborne rain radar;

[0112] Step S5.2: Evaluate the effectiveness of the spaceborne rain radar in detecting the typhoon to be detected. If d ⊥ is greater than the scanning track swath of the spaceborne rain radar, in the current working mode of the spaceborne rain radar, it is impossible to effectively observe the typhoon to be detected, and the satellite is maneuvered to increase the effective observation range;

[0113] If d ⊥ is less than the scanning track swath of the spaceborne rain radar, the current spaceborne rain radar can effectively observe the typhoon, and the spaceborne rain radar is ordered to continue the observation.

[0114] Example 1

[0115] The present invention obtains parameters such as the position, satellite position, velocity, and attitude of the typhoon to be detected at the current moment, the detection angle range of the rain radar, and the scanning track swath; calculates the position and velocity of the satellite sub-satellite point in the WGS84 coordinate system (geocentric coordinate system) at the current moment; calculates the angle between the satellite velocity vector and the satellite sub-satellite point-typhoon connection line at the current moment; projects the satellite sub-satellite point-typhoon connection line onto the cross-track scanning direction of the spaceborne rain radar; compares the projected distance of the satellite sub-satellite point-typhoon connection line with the scanning track swath of the rain radar to evaluate whether the spaceborne rain radar can effectively detect the typhoon to be detected.

[0116] According to a method for on-orbit evaluating the effectiveness of a spaceborne rain radar in detecting typhoons provided by the present invention, as Figure 2 shown, it includes the following steps:

[0117] Step S1: Obtain the central position of the typhoon to be detected at the current moment, obtain the satellite position, velocity and attitude according to the working state parameters of the satellite platform, and obtain the detection angle range and scanning orbit swath according to the working state parameters of the rain measuring radar. The position of the typhoon to be measured at the current moment refers to the longitude and latitude information of the typhoon center position. The working state parameters of the satellite platform and the rain measuring radar can be obtained from the payload remote sensing data packet, including satellite position, velocity and attitude, radar detection angle range and scanning orbit swath.

[0118] Step S2: Calculate the position and velocity of the satellite sub-satellite point in the WGS84 coordinate system at the current moment. When the spaceborne rain measuring radar is in the on-orbit working state, first convert the initial detection visual axis of the radar to the detection wave position visual axis through the payload installation matrix and the coordinate system transformation matrix. Specifically, let both the payload installation matrix and the coordinate system transformation matrix form a 3×3 matrix form, and use the initial detection visual axis to perform a dot product with the above two matrices to convert to the detection wave position visual axis, and obtain the visual vector according to the detection angle of the satellite sub-satellite point. Among them, the payload installation matrix is set according to the specific installation method, and the coordinate system transformation matrix is a set of matrixes of the transformation mapping relationship of points before and after the coordinate system transformation. By interpolating the satellite velocity, satellite position and satellite attitude in multiple periods, specifically, taking the satellite parameters of the current period, the previous period and the next period, and performing one-dimensional linear interpolation using the linear interpolation formula to obtain the satellite parameters at the current moment, and by calculating the intersection point of the visual vector of the satellite and the earth's surface, obtain the position and velocity of the satellite sub-satellite point in the WGS84 coordinate system at the current moment.

[0119] Step S3: Calculate the angle between the satellite velocity vector and the line connecting the satellite sub-satellite point and the typhoon at the current moment. Using the position of the satellite sub-satellite point, that is, the longitude and latitude coordinates in the WGS84 coordinate system, combined with the longitude and latitude of the typhoon center, calculate the distance between the satellite sub-satellite point and the typhoon; calculate the angle between the satellite velocity vector at the current moment and the line connecting the satellite sub-satellite point and the typhoon. First, convert the longitude and latitude of the typhoon center to be measured to obtain its xyz coordinates, and the calculation formula is as follows:

[0120]

[0121] where (x t , y t , z t ) represents the coordinates of the typhoon center to be measured in the WGS84 coordinate system, represents the latitude and longitude coordinates of the typhoon center to be measured, and R e represents the radius of the earth.

[0122] After obtaining the satellite sub-satellite point coordinates and the position of the typhoon center to be measured, calculate the connection distance, and the calculation formula is as follows:

[0123]

[0124] In the formula, d represents the connection distance, and (x s , y s , z s ) represents the coordinates of the satellite sub-satellite point, and (x t , y t , z t ) represents the coordinates of the center position of the typhoon to be measured.

[0125] Using the connection line between the satellite sub-satellite point and the typhoon and the satellite velocity vector at the current moment, the included angle between the two can be obtained, and the calculation formula is as follows:

[0126]

[0127] In the formula, θ represents the included angle between the satellite velocity vector at the current moment and the connection line between the satellite sub-satellite point and the typhoon, and (v x , v y , v z ) represents the satellite velocity vector at the current moment.

[0128] Step S4: Project the connection line between the satellite sub-satellite point and the typhoon onto the cross-track scanning direction of the spaceborne rain radar. Using the distance of the connection line between the satellite sub-satellite point and the typhoon and the included angle between this connection line and the satellite velocity vector, project this connection line in the cross-track scanning direction of the spaceborne radar to obtain the projection distance of the connection line between the satellite sub-satellite point and the typhoon at the current moment in the cross-track scanning direction of the radar. The calculation formula is as follows:

[0129] d ⊥ = d × sinθ

[0130]

[0131] In the formula, θ represents the included angle between the satellite velocity vector at the current moment and the connection line between the satellite sub-satellite point and the typhoon, d represents the distance of the connection line between the satellite sub-satellite point and the typhoon at the current moment, and d ⊥ represents the projection distance of the connection line between the satellite sub-satellite point and the typhoon at the current moment in the cross-track scanning direction of the radar.

[0132] Step S5: Compare the projected distance of the connection line between the satellite sub-satellite point and the typhoon with the swath of the rain radar scanning orbit to evaluate whether the spaceborne rain radar can effectively detect the typhoon to be detected. According to the projection distance of the connection line between the satellite sub-satellite point and the typhoon at the current moment in the cross-track scanning direction of the spaceborne radar and the swath of the rain radar scanning orbit, compare and analyze the two. If the former is larger, then in the current working mode of the spaceborne rain radar, it is impossible to effectively observe the typhoon to be detected, and satellite maneuvering is required to increase the effective observation range; otherwise, the typhoon can be effectively observed. Realize the in-orbit evaluation of the effectiveness of the spaceborne rain radar in detecting typhoons.

[0133] Further, in combination with the attached Figure 2 and Figure 3 , the method for on-orbit evaluating the effectiveness of a spaceborne rain radar in detecting typhoons according to the present invention is specifically described as follows:

[0134] By obtaining the central position of the typhoon to be detected at the current moment, the satellite position, velocity, and attitude are obtained according to the satellite platform operating state parameters, and the detection angle range and scanning orbit swath are obtained according to the rain radar operating state parameters. The position of the typhoon to be detected at the current moment refers to the longitude and latitude information of the typhoon center position. The operating state parameters of the satellite platform and the rain radar can be obtained from the payload remote sensing data packet, including the satellite position, velocity, and attitude, the radar detection angle range, and the scanning orbit swath.

[0135] Calculate the position and velocity of the satellite sub-satellite point in the WGS84 coordinate system at the current moment. When the spaceborne rain radar is in the on-orbit working state, first, the initial detection visual axis of the radar is converted to the detection wave position visual axis through the payload installation matrix and the coordinate system conversion matrix, and the visual vector is obtained according to the detection angle of the satellite sub-satellite point; by interpolating the satellite velocity, satellite position, and satellite attitude in multiple periods, the intersection point of the visual vector and the earth's surface is calculated to obtain the position and velocity of the satellite sub-satellite point in the WGS84 coordinate system at the current moment.

[0136] Calculate the included angle between the satellite velocity vector and the line connecting the satellite sub-satellite point and the typhoon at the current moment. Using the position of the satellite sub-satellite point, that is, the longitude and latitude coordinates in the WGS84 coordinate system, combined with the longitude and latitude of the typhoon center, calculate the distance between the satellite sub-satellite point and the typhoon; calculate the included angle between the satellite velocity vector and the line connecting the satellite sub-satellite point and the typhoon at the current moment. First, the xyz coordinates of the typhoon center to be detected are obtained through conversion, and the calculation formula is as follows:

[0137]

[0138] In the formula, (x t , y t , z t ) represents the coordinates of the typhoon center to be detected in the WGS84 coordinate system, represents the latitude and longitude coordinates of the typhoon center to be detected, and R e represents the radius of the earth.

[0139] After obtaining the satellite sub-satellite point coordinates and the position of the typhoon center to be detected, calculate the connection distance, and the calculation formula is as follows:

[0140]

[0141] In the formula, d represents the connection distance, (x s , y s , z s ) represents the satellite sub-satellite point coordinates, (x t, y t , z t ) represents the coordinates of the typhoon center to be measured.

[0142] Using the satellite sub-satellite point - typhoon connection line and the satellite velocity vector at the current moment, the included angle between the two can be obtained. The calculation formula is as follows:

[0143]

[0144] In the formula, θ represents the included angle between the satellite velocity vector at the current moment and the satellite sub-satellite point - typhoon connection line, (v x , v y , v z ) represents the satellite velocity vector at the current moment.

[0145] Project the satellite sub-satellite point - typhoon connection line onto the cross-track scanning direction of the spaceborne rain radar. Using the distance of the satellite sub-satellite point - typhoon connection line and the included angle between this connection line and the satellite velocity vector, project this connection line in the cross-track scanning direction of the spaceborne radar to obtain the projection distance of the satellite sub-satellite point - typhoon connection line at the current moment in the cross-track scanning direction of the radar. The calculation formula is as follows:

[0146] d ⊥ = d × sinθ

[0147]

[0148] In the formula, θ represents the included angle between the satellite velocity vector at the current moment and the satellite sub-satellite point - typhoon connection line, d represents the distance of the satellite sub-satellite point - typhoon connection line at the current moment, and d ⊥ represents the projection distance of the satellite sub-satellite point - typhoon connection line at the current moment in the cross-track scanning direction of the radar.

[0149] Compare the distance of the satellite sub-satellite point - typhoon connection line after projection with the swath of the rain radar scanning orbit to evaluate whether the spaceborne rain radar can effectively detect the typhoon to be detected. According to the projection distance of the satellite sub-satellite point - typhoon connection line at the current moment in the cross-track scanning direction of the spaceborne radar and the swath of the rain radar scanning orbit, compare and analyze the two. Their relationship is as Figure 2 shown. If the former is larger, then in the current working mode of the spaceborne rain radar, it is impossible to effectively observe the typhoon to be detected, and satellite maneuvering is required to increase the effective observation range; otherwise, the typhoon can be effectively observed. Realize the on-orbit evaluation of the effectiveness of the spaceborne rain radar in detecting typhoons.

[0150] The present invention also provides a system for on-orbit evaluating the effectiveness of spaceborne rain radar in detecting typhoons. The system for on-orbit evaluating the effectiveness of spaceborne rain radar in detecting typhoons can be implemented by executing the process steps of the method for on-orbit evaluating the effectiveness of spaceborne rain radar in detecting typhoons. That is, those skilled in the art can understand the method for on-orbit evaluating the effectiveness of spaceborne rain radar in detecting typhoons as a preferred implementation manner of the system for on-orbit evaluating the effectiveness of spaceborne rain radar in detecting typhoons.

[0151] The present invention also provides a system for on-orbit evaluating the effectiveness of spaceborne rain radar in detecting typhoons. The system for on-orbit evaluating the effectiveness of spaceborne rain radar in detecting typhoons can be implemented by executing the process steps of the method for on-orbit evaluating the effectiveness of spaceborne rain radar in detecting typhoons. That is, those skilled in the art can understand the method for on-orbit evaluating the effectiveness of spaceborne rain radar in detecting typhoons as a preferred implementation manner of the system for on-orbit evaluating the effectiveness of spaceborne rain radar in detecting typhoons.

[0152] A system for on-orbit evaluating the effectiveness of spaceborne rain radar in detecting typhoons according to the present invention includes:

[0153] Module M1: Obtain the central position of the typhoon to be detected at the current moment, obtain the satellite position, speed and attitude according to the satellite platform working state parameters, and obtain the detection angle range and scanning orbit swath according to the rain radar working state parameters. The position of the typhoon to be detected at the current moment refers to the longitude and latitude information of the typhoon center position. The working state parameters of the satellite platform and the rain radar can be obtained from the payload remote sensing data packet, including the satellite position, speed and attitude, the radar detection angle range and the scanning orbit swath.

[0154] Module M2: Calculate the position and speed of the satellite sub-satellite point in the WGS84 coordinate system at the current moment. When the spaceborne rain radar is in the on-orbit working state, first convert the initial detection visual axis of the radar to the detection wave position visual axis through the payload installation matrix and the coordinate system conversion matrix, and obtain the visual vector according to the detection angle of the satellite sub-satellite point; by interpolating the satellite speed, satellite position and satellite attitude in multiple periods, calculate the intersection point of the visual vector and the earth's surface, and obtain the position and speed of the satellite sub-satellite point in the WGS84 coordinate system at the current moment.

[0155] Module M3: Calculate the included angle between the satellite velocity vector and the line connecting the satellite sub-satellite point and the typhoon at the current moment. Using the position of the satellite sub-satellite point, that is, the longitude and latitude coordinates in the WGS84 coordinate system, combined with the longitude and latitude of the typhoon center, calculate the distance between the satellite sub-satellite point and the typhoon; calculate the included angle between the satellite velocity vector at the current moment and the line connecting the satellite sub-satellite point and the typhoon. First, convert the longitude and latitude of the typhoon center to its xyz coordinates, and the calculation formula is as follows:

[0156]

[0157] where (x t , y t , z t ) represents the coordinates of the typhoon center to be measured in the WGS84 coordinate system, represents the latitude and longitude coordinates of the typhoon center to be measured, and R e represents the radius of the earth.

[0158] After obtaining the satellite sub-satellite point coordinates and the position of the typhoon center to be measured, calculate the connection distance. The calculation formula is as follows:

[0159]

[0160] where d represents the connection distance, and (x s , y s , z s ) represents the satellite sub-satellite point coordinates, and (x t , y t , z t ) represents the position coordinates of the typhoon center to be measured.

[0161] Using the satellite sub-satellite point - typhoon connection line and the satellite velocity vector at the current moment, the included angle between the two can be obtained. The calculation formula is as follows:

[0162]

[0163] where θ represents the included angle between the satellite velocity vector at the current moment and the satellite sub-satellite point - typhoon connection line, and (v x , v y , v z ) represents the satellite velocity vector at the current moment.

[0164] Module M4: Project the satellite sub-satellite point - typhoon connection line onto the cross-track scanning direction of the spaceborne rain radar. Using the connection distance between the satellite sub-satellite point and the typhoon and the included angle between this connection line and the satellite velocity vector, project this connection line onto the cross-track scanning direction of the spaceborne radar to obtain the projection distance of the satellite sub-satellite point - typhoon connection line at the current moment in the radar cross-track scanning direction. The calculation formula is as follows:

[0165] d ⊥ = d × sinθ

[0166]

[0167] where θ represents the included angle between the satellite velocity vector at the current moment and the satellite sub-satellite point - typhoon connection line, d represents the connection distance between the satellite sub-satellite point and the typhoon at the current moment, and d ⊥ represents the projection distance of the satellite sub-satellite point - typhoon connection line at the current moment in the radar cross-track scanning direction.

[0168] ​​​​​​​​​​​​​Module M5: Compare the projected distance between the sub-satellite point of the satellite and the typhoon connection line with the swath of the rain measuring radar scan orbit to evaluate whether the spaceborne rain measuring radar can effectively detect the typhoon to be detected. According to the projected distance between the sub-satellite point of the satellite and the typhoon connection line in the cross-track scanning direction of the spaceborne radar and the swath of the rain measuring radar scan orbit, compare and analyze the two. If the former is larger, in the current working mode of the spaceborne rain measuring radar, it is impossible to effectively observe the typhoon to be detected, and satellite maneuvering is required to increase the effective observation range; otherwise, the typhoon can be effectively observed. Realize the on-orbit evaluation of the effectiveness of the spaceborne rain measuring radar in detecting typhoons.

[0169] Those skilled in the art know that in addition to implementing the system and its various devices, modules, and units provided by the present invention in the form of pure computer-readable program code, the method steps can be logically programmed to enable the system and its various devices, modules, and units provided by the present invention to be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers to achieve the same function. Therefore, the system and its various devices, modules, and units provided by the present invention can be regarded as a kind of hardware component, and the devices, modules, and units included therein for implementing various functions can also be regarded as the structure within the hardware component; the devices, modules, and units for implementing various functions can also be regarded as both software modules for implementing the method and the structure within the hardware component.

[0170] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. Without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A method for evaluating the effectiveness of spaceborne precipitation radar in detecting typhoons on-orbit, characterized in that: include: Step S1: obtaining the center position parameters of the typhoon to be detected, and at the same time obtaining the dynamic parameters of the satellite and the detection angle range and scanning orbit swath of the satellite-borne rainfall radar; Step S2: Calculate the position and speed of the sub-satellite point in the geocentric coordinate system at the current moment according to the acquired parameters, and form a position line connecting the sub-satellite point and the typhoon position; Step S3: Calculate the distance and angle between the current position and the center position of the typhoon to be detected according to the satellite subsatellite position; Step S4: according to the distance and angle of the position line, project the position line to the cross-track scanning direction of the satellite-borne precipitation radar to obtain the projection distance; Step S5: By comparing the projection distance and the scanning track swath of the satellite-borne precipitation radar, the effectiveness of the satellite-borne precipitation radar in detecting the typhoon to be detected is evaluated.

2. The method for evaluating the effectiveness of satellite-borne precipitation radar in detecting typhoons on-orbit according to claim 1, characterized in that: The step S1 comprises: The satellite position, satellite speed and satellite attitude parameters are obtained according to the working status parameters of the satellite platform, and the detection angle range and scanning orbit swath of the satellite-borne precipitation measuring radar are obtained according to the working status parameters of the precipitation measuring radar; The typhoon position parameters to be measured at the current moment are the longitude and latitude parameters of the typhoon center position.

3. The method for evaluating the effectiveness of satellite-borne precipitation radar in detecting typhoons on-orbit according to claim 1, characterized in that: The step S2 comprises: Step S2.1: When the satellite-borne precipitation radar is in an on-orbit working state, the radar initial detection boresight is converted to the detection wave position boresight through the payload installation matrix and the coordinate system conversion matrix, and the viewing vector is obtained according to the satellite sub-satellite point detection angle; Step S2.2: By interpolating the multi-period satellite velocity, satellite position and satellite attitude, the intersection of the view vector and the earth's surface is calculated to obtain the position and velocity of the satellite sub-satellite point in the geocentric coordinate system at the current moment; Step S2.3: Connect the satellite sub-satellite point and the typhoon position to form a position line.

4. The method for evaluating the effectiveness of satellite-borne precipitation radar in detecting typhoons on-orbit according to claim 1, characterized in that: The step S3 comprises: Step S3.1: The coordinates of the typhoon center to be measured in the geocentric coordinate system are obtained by converting the longitude and latitude of the typhoon center to be measured. The calculation formula is as follows: Where (x t ,y t ,z t ) represents the coordinates of the typhoon center to be measured in the geocentric coordinate system, Indicates the latitude and longitude coordinates of the center of the typhoon to be measured, R e represents the radius of the Earth; Step S3.2: Calculate the distance between the positions. The calculation formula is as follows: Where d represents the connection distance, (x s ,y s ,z s ) represents the sub-satellite point coordinates; Step S3.3: Calculate the angle between the satellite velocity vector and the position line at the current moment according to the satellite subsatellite point coordinates, the coordinates of the typhoon center position to be measured, the distance between the position lines and the satellite velocity vector at the current moment. The calculation formula is as follows: Where θ represents the angle between the satellite velocity vector and the position line at the current moment, (v x ,v y ,v z ) represents the satellite velocity vector at the current moment.

5. The method for on-orbit evaluation of the effectiveness of satellite-borne precipitation radar in detecting typhoons according to claim 1, characterized in that: The step S4 comprises: According to the position line distance and the angle θ, the position line is projected in the cross-track scanning direction of the satellite-borne precipitation radar to obtain the projection distance of the position line in the radar cross-track scanning direction at the current moment. The calculation formula is as follows: d ⊥ =d×sinθ Where d ⊥ It indicates the projection distance of the current position line in the cross-track scanning direction of the satellite-borne precipitation radar.

6. The method for on-orbit evaluation of the effectiveness of satellite-borne precipitation radar in detecting typhoons according to claim 1, characterized in that: The step S5 comprises: Step S5.1: Let the projection distance d of the line connecting the current position in the cross-track scanning direction of the satellite-borne precipitation radar be ⊥ Comparison with the scanning track swath of the satellite-borne precipitation radar; Step S5.2: Evaluate the effectiveness of spaceborne precipitation radar in detecting the typhoon to be detected. ⊥ If the range is larger than the scanning track width of the satellite-borne precipitation radar, then under the current satellite-borne precipitation radar working mode, it is impossible to effectively observe the typhoon to be detected, so the satellite should be maneuvered to increase the effective observation range; If d ⊥ If it is smaller than the scanning orbit swath of the satellite-borne precipitation measuring radar, the current satellite-borne precipitation measuring radar can effectively observe the typhoon, and the satellite-borne precipitation measuring radar can continue to observe.

7. A system for evaluating the effectiveness of spaceborne precipitation radar in detecting typhoons on orbit, characterized in that: include: Module M1: Obtain the center position parameters of the typhoon to be detected, and at the same time obtain the dynamic parameters of the satellite and the detection angle range and scanning orbit swath of the satellite-borne rainfall radar; Module M2: Calculate the position and speed of the satellite sub-satellite point in the geocentric coordinate system at the current moment based on the acquired parameters, and form a position line between the satellite sub-satellite point and the typhoon position; Module M3: Calculate the distance and angle between the current position of the line connecting the satellite subsatellite point and the center of the typhoon to be detected; Module M4: Based on the distance and angle of the position line, the position line is projected to the cross-track scanning direction of the satellite-borne precipitation radar to obtain the projection distance; Module M5: Evaluate the effectiveness of spaceborne precipitation radar in detecting the typhoon by comparing the projection distance and the scanning track swath of the spaceborne precipitation radar.

8. The system for evaluating the effectiveness of space-borne precipitation radar in detecting typhoons on-orbit according to claim 7, characterized in that: The module M1 comprises: The satellite position, satellite speed and satellite attitude parameters are obtained according to the working status parameters of the satellite platform, and the detection angle range and scanning orbit swath of the satellite-borne precipitation measuring radar are obtained according to the working status parameters of the precipitation measuring radar; The typhoon position parameters to be measured at the current moment are the longitude and latitude parameters of the typhoon center position; The module M2 comprises: Module M2.1: When the satellite-borne precipitation radar is in orbit, the initial detection axis of the radar is converted to the detection wave position axis through the payload installation matrix and the coordinate system conversion matrix, and the line of sight vector is obtained according to the detection angle of the sub-satellite point; Module M2.2: By interpolating the multi-period satellite velocity, satellite position and satellite attitude, the intersection of the view vector and the earth's surface is calculated to obtain the position and velocity of the satellite sub-satellite point in the geocentric coordinate system at the current moment; Module M2.3: Connect the satellite sub-satellite point with the typhoon position to form a position line.

9. The system for evaluating the effectiveness of space-borne precipitation radar in detecting typhoons on-orbit according to claim 7, characterized in that: The module M3 comprises: Module M3.1: The coordinates of the typhoon center to be measured in the geocentric coordinate system are obtained by converting the longitude and latitude of the typhoon center to be measured. The calculation formula is as follows: Where (x t ,y t ,z t ) represents the coordinates of the typhoon center to be measured in the geocentric coordinate system, Indicates the latitude and longitude coordinates of the center of the typhoon to be measured, R e represents the radius of the Earth; Module M3.2: Calculate the distance between the positions. The calculation formula is as follows: Where d represents the connection distance, (x s ,y s ,z s ) represents the sub-satellite point coordinates; Module M3.3: Calculate the angle between the satellite velocity vector and the position line at the current moment according to the satellite subsatellite point coordinates, the coordinates of the typhoon center to be measured, the distance between the position lines and the satellite velocity vector at the current moment. The calculation formula is as follows: Where θ represents the angle between the satellite velocity vector and the position line at the current moment, (v x ,v y ,v z ) represents the satellite velocity vector at the current moment; The module M4 comprises: According to the position line distance and the angle θ, the position line is projected in the cross-track scanning direction of the satellite-borne precipitation radar to obtain the projection distance of the position line in the radar cross-track scanning direction at the current moment. The calculation formula is as follows: d ⊥ =d×sinθ Where d ⊥ It indicates the projection distance of the current position line in the cross-track scanning direction of the satellite-borne precipitation radar.

10. The system for evaluating the effectiveness of space-borne precipitation radar in detecting typhoons on-orbit according to claim 7, characterized in that: The module M5 comprises: Module M5.1: Let the projection distance d of the line connecting the current position in the cross-track scanning direction of the satellite-borne precipitation radar be ⊥ Comparison with the scanning track swath of the satellite-borne precipitation radar; Module M5.2: Evaluate the effectiveness of spaceborne precipitation radar for detecting typhoons to be detected. ⊥ If the range is larger than the scanning track width of the satellite-borne precipitation radar, then under the current satellite-borne precipitation radar working mode, it is impossible to effectively observe the typhoon to be detected, so the satellite should be maneuvered to increase the effective observation range; If d ⊥ If it is smaller than the scanning orbit swath of the satellite-borne precipitation measuring radar, the current satellite-borne precipitation measuring radar can effectively observe the typhoon, and the satellite-borne precipitation measuring radar can continue to observe.

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