Motion compensation imaging model construction method of imaging spectrometer, imaging model and device

Abstract

The invention provides an imaging spectrometer motion compensation imaging model construction method, an imaging model and a device, and relates to the technical field of space remote sensing. The method comprises the following steps: establishing a satellite orbit model, and defining a plurality of coordinate systems such as a detector coordinate system and a spectrometer imaging coordinate system and a conversion relation thereof; constructing a detector-scanning mirror-lunar surface ideal geometric mapping model based on the load optical parameters and a ray tracing method; determining the relation between the rotation angle of the scanning mirror and imaging spectrum view field positioning by using a reflecting prism conjugation theory; a quantitative relation is established by combining parameters such as satellite orbits and position postures, and finally a motion compensation imaging model is established. According to the method, the influence of the on-orbit error on the compensation imaging model is analyzed, and the error is used as an uncertainty component to be coupled into the model. According to the method, the problems of low model precision, neglect of influence of orbit observation parameters on imaging and the like in the prior art are solved, high-precision motion estimation and compensation can be realized, and the quality of data acquired by an imaging spectrometer is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the field of aerospace remote sensing technology, and in particular to a method for constructing a motion compensation imaging model of an imaging spectrometer. Background Art

[0002] In existing aerospace remote sensing observation missions, imaging spectrometers are an important optical remote sensing payload that can obtain two-dimensional images and spectral information of targets. However, due to the high-speed movement and attitude changes of imaging satellites, which can cause a decrease in imaging quality, it is necessary to perform motion compensation processing on the images during dynamic acquisition. Currently, commonly used motion compensation methods are mainly based on the measured orbit and attitude data, combined with existing geometric optical models to describe the imaging process, and then apply algorithms such as image matching to calculate motion parameters for compensation. However, this type of method has the following problems:

[0003] 1. Existing models are mainly based on geometric optics theory and lack consideration of error factors such as optical system aberrations and noise, which affects model accuracy;

[0004] 2. The complex effects of orbital observation parameters such as satellite platform motion and pointing changes on imaging are ignored;

[0005] 3. The potential coupling relationship between orbital data and optical remote sensing data is not fully utilized, making it difficult to simultaneously improve orbit determination and imaging quality. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for constructing a motion-compensated imaging model for an imaging spectrometer, which can construct a motion-compensated imaging model for an imaging spectrometer that comprehensively considers the combined influence of orbital observation parameters and system errors, thereby achieving high-precision motion estimation and compensation under complex dynamic observation conditions, and improving the quality of data acquired by the imaging spectrometer.

[0007] To achieve the above object, the present invention is implemented through the following technical solutions:

[0008] A method for constructing a motion compensation imaging model for an imaging spectrometer comprises the following steps:

[0009] S1: Establish satellite orbit model;

[0010] S2: Construct the detector coordinate system, spectrometer imaging coordinate system, scanning mirror coordinate system, satellite body coordinate system, lunar inertial system and lunar longitude and latitude coordinate system, and determine the conversion relationship between each coordinate system;

[0011] S3: Based on the payload optical parameters and ray tracing method, an ideal geometric mapping model of the detector-scanning mirror-lunar surface is constructed;

[0012] S4: Using the conjugate theory of reflecting prisms, determine the relationship between the scanning mirror rotation angle and the imaging spectrum field of view positioning;

[0013] S5: Combine the satellite orbit, position attitude, ephemeris and detection time parameters to establish the quantitative relationship between motor angle, orbit and target longitude and latitude;

[0014] S6: Integrate the satellite orbit model, the coordinate system conversion relationship, the ideal geometric mapping model, the relationship between the scanning mirror rotation angle and the imaging spectrum field of view, and the quantitative relationship between the motor rotation angle, orbit, and target longitude and latitude to establish a motion compensation imaging model for compensating for the influence of the on-orbit motion of the imaging spectrometer;

[0015] S7: Analyze the impact of on-orbit errors on the compensation imaging model under lunar circumnavigation conditions, and couple the errors into the compensation imaging model as uncertainty components.

[0016] Furthermore: in the step S1, an orbit model of the satellite is established by using six orbital parameters and a satellite toolkit, wherein the six orbital parameters include semi-major axis, eccentricity, orbital inclination, right ascension of ascending node, argument of perigee and mean anomaly.

[0017] 10. Further: In step S2, according to the law of reflection, the scanning mirror rotation angle θ is established s The relationship between the angle change φ of the reflected light direction satisfies φ=2θ s Based on the focal length f of the imaging spectrometer, the height H of the observation track, and the scanning field of view, the geometric relationship between the scanning mirror rotation angle and the ground target point positioning offset Δx is established, where:

[0018] Δx=2Htanθ s

[0019] Combining the above relationships, the scanning mirror rotation angle θ is constructed s A quantitative model for positioning the field of view of an imaging spectrometer is used to achieve high-precision scanning and positioning of the target area.

[0020] Furthermore: in step S3, the construction of the ideal geometric mapping model includes determining the light transmission path of the load end.

[0021] Furthermore, the step S5 also includes considering the payload imaging time, the motion compensation scanning angle, the satellite's on-orbit position and attitude, and performing a simulation of the coverage area of ​​the motion compensation push-broom imaging.

[0022] Furthermore, in step S7, the on-orbit errors analyzed include one or more of the following: instrument and reflection mechanism installation error, reflection mechanism stability and accuracy error, refrigerator vibration error, orbit drift error, and measurement track error.

[0023] Furthermore: for errors that can be precisely measured, the error parameters are measured through a reference mirror, a grating encoder or a theodolite, and the compensation imaging model is corrected accordingly.

[0024] Furthermore: for errors that cannot be accurately measured, they are coupled into the compensation imaging model as uncertainty components according to the error distribution characteristics.

[0025] The present invention also provides an imaging spectrometer motion compensation imaging model constructed based on the above-mentioned method, wherein the model includes an orbit model, a coordinate system transformation relationship, an ideal geometric mapping model, a scanning mirror rotation angle and an imaging spectrum field positioning relationship, a motor angle-orbit-target longitude and latitude quantization relationship, and a compensation imaging model coupled with an error uncertainty component.

[0026] The present invention also provides a device for implementing the above method, comprising:

[0027] processor;

[0028] memory for storing computer programs;

[0029] Wherein, when the processor executes the computer program, the method steps described in any one of claims 1 to 7 are implemented.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. The present invention establishes a comprehensive satellite orbit model, introduces consideration of error factors such as optical system aberrations and noise, improves the accuracy of the motion compensation imaging model, and solves the problem that the existing model only relies on geometric optics theory and ignores error factors.

[0032] Second, the present invention takes into account the complex effects of orbital observation parameters such as satellite platform motion and pointing changes on imaging, making up for the defect of the existing technology that ignores the impact of these factors on imaging quality, thereby improving imaging quality.

[0033] 3. The present invention fully combines the potential coupling relationship between orbital data and optical remote sensing data, thereby improving the accuracy of orbit determination while also optimizing imaging quality, achieving joint progress in both orbit determination and imaging quality.

[0034] 4. The present invention analyzes the impact of on-orbit errors on the compensation imaging model and couples these errors into the model as uncertainty components, thereby further enhancing the adaptability and robustness of the model and ensuring effective motion compensation under different orbital conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1Schematic diagram of a flow chart of a method for constructing a motion compensation imaging model for an imaging spectrometer according to an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0037] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0038] This invention relates to a method for constructing a motion-compensated imaging model for an imaging spectrometer. This method aims to address the existing problem of reduced imaging quality caused by a lack of consideration of the combined effects of orbital observation parameters and system errors. This method enables high-precision motion estimation and compensation under complex dynamic observation conditions, thereby improving the quality of data acquired by the imaging spectrometer.

[0039] First, a satellite orbit model is established. This model is based on six orbital parameters (including semi-major axis, eccentricity, orbital inclination, right ascension of the ascending node, argument of perigee, and mean anomaly) and a satellite toolkit (such as STK). These parameters accurately describe the satellite's motion in lunar orbit, providing a foundation for subsequent motion compensation of the imaging spectrometer.

[0040] Next, we define multiple related coordinate systems, including the detector coordinate system, the spectrometer imaging coordinate system, the scanning mirror coordinate system, the satellite body coordinate system, the lunar inertial system, and the lunar latitude and longitude coordinate system, and study the transformation relationships between these coordinate systems. The definition of these coordinate systems helps to accurately describe the path of light from the detector through the scanning mirror to the lunar surface.

[0041] Then, based on the payload's optical parameters and ray tracing, an ideal geometric mapping model of the detector-scanning mirror-lunar surface was constructed. This step utilized the conjugate theory of reflecting prisms to explore the relationship between the scanning mirror's rotation angle and the imaging spectral field of view, ensuring that the scanning mirror's angle adjustment accurately aligned the detector with the target area.

[0042] Next, the satellite's orbit, position, attitude, ephemeris, and detection time parameters are combined to determine the quantitative relationship between the motor angle, orbital parameters, and the target's longitude and latitude. This establishes a light transmission link from the detector to the target's longitude and latitude, paving the way for the creation of a motion-compensated imaging model.

[0043] On this basis, a motion-compensated imaging model is established. This model comprehensively considers the results of all the above steps and can more accurately describe the imaging process of the imaging spectrometer under dynamic observation conditions.

[0044] Furthermore, the impact of on-orbit errors on the compensation imaging model during lunar orbital exploration needs to be analyzed. For error parameters that can be measured using devices such as reference mirrors, grating encoders, or theodolites, the compensation imaging model should be modified. For errors that cannot be directly measured, such as cryostat vibration errors and orbital drift errors during on-orbit operation, these should be coupled into the compensation imaging model as uncertainty components based on their distribution characteristics.

[0045] Through the above steps, the present invention provides a novel method for constructing a motion-compensated imaging model for an imaging spectrometer. This method overcomes existing challenges and improves imaging quality. Specifically, this method fully considers the combined effects of orbital observation parameters and system errors when constructing the model, improving the accuracy and robustness of motion compensation. This allows for high-quality imaging spectral data acquisition even under complex dynamic observation conditions.

[0046] The technical solution of this application will be described in detail below through specific embodiments.

[0047] A method for constructing a motion compensation imaging model for an imaging spectrometer comprises the following steps:

[0048] S1: Establish satellite orbit model;

[0049] In some embodiments, an orbit model of a satellite is established using six orbital numbers and a satellite toolkit, wherein the six orbital numbers include semi-major axis, eccentricity, orbit inclination, right ascension of ascending node, argument of perigee and mean anomaly.

[0050] S2: Construct the detector coordinate system, spectrometer imaging coordinate system, scanning mirror coordinate system, satellite body coordinate system, lunar inertial system and lunar longitude and latitude coordinate system, and determine the conversion relationship between each coordinate system;

[0051] Specifically, in step S2, according to the law of reflection, the scanning mirror rotation angle θ is established. s The relationship between the angle change φ of the reflected light direction satisfies φ=2θ sBased on the focal length f of the imaging spectrometer, the height H of the observation track, and the scanning field of view, the geometric relationship between the scanning mirror rotation angle and the ground target point positioning offset Δx is established, where:

[0052] Δx=2Htanθ s

[0053] Combining the above relationships, the scanning mirror rotation angle θ is constructed s A quantitative model for positioning the field of view of an imaging spectrometer is used to achieve high-precision scanning and positioning of the target area.

[0054] The specific coordinate system construction method and the conversion relationship between each coordinate system refer to the national standard document GB / T 30112-2013 on the lunar space coordinate system issued by the Standardization Administration of China on December 17, 2013.

[0055] S3: Based on the payload optical parameters and ray tracing method, an ideal geometric mapping model of the detector-scanning mirror-lunar surface is constructed;

[0056] In some embodiments, constructing the ideal geometric mapping model includes determining a light transmission path at the load end;

[0057] S4: Using the conjugate theory of reflecting prisms, determine the relationship between the scanning mirror rotation angle and the imaging spectrum field of view positioning;

[0058] S5: Combine the satellite orbit, position attitude, ephemeris and detection time parameters to establish the quantitative relationship between motor angle, orbit and target longitude and latitude;

[0059] In some embodiments, it also includes considering the payload imaging time, motion compensation scanning angle, satellite on-orbit position and attitude, and performing coverage area simulation of motion compensated push-broom imaging.

[0060] S6: Integrate the satellite orbit model, the coordinate system conversion relationship, the ideal geometric mapping model, the relationship between the scanning mirror rotation angle and the imaging spectrum field of view, and the quantitative relationship between the motor rotation angle, orbit, and target longitude and latitude to establish a motion compensation imaging model for compensating for the influence of the on-orbit motion of the imaging spectrometer;

[0061] S7: Analyze the impact of on-orbit errors on the compensation imaging model under lunar circumnavigation conditions, and couple the errors into the compensation imaging model as uncertainty components.

[0062] In some embodiments, the analyzed on-orbit errors include one or more of the following: instrument and reflection mechanism installation errors, reflection mechanism stability and accuracy errors, refrigerator vibration errors, orbit drift errors, and measurement track errors.

[0063] Among them, for errors that can be accurately measured, the error parameters are measured through a reference mirror, grating encoder or theodolite, and the compensation imaging model is corrected accordingly; for errors that cannot be accurately measured, they are coupled into the compensation imaging model as uncertainty components according to the error distribution characteristics.

[0064] In other embodiments, the present invention also provides an imaging spectrometer motion compensation imaging model constructed based on the above-mentioned method, wherein the model includes a track model, a coordinate system transformation relationship, an ideal geometric mapping model, a scanning mirror rotation angle and an imaging spectrum field of view positioning relationship, a motor angle-track-target longitude and latitude quantization relationship, and a compensation imaging model coupled with an error uncertainty component.

[0065] In another embodiment, the present invention further provides an apparatus for implementing the above method, comprising:

[0066] processor;

[0067] memory for storing computer programs;

[0068] Wherein, when the processor executes the computer program, the method steps described in any one of claims 1 to 7 are implemented.

[0069] The above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made in accordance with the spirit of the present invention are intended to be covered by the scope of protection of the present invention.

Claims

1. A method for constructing a motion compensation imaging model for an imaging spectrometer, characterized in that: The following steps are involved: S1: Establish satellite orbit model; S2: Construct the detector coordinate system, spectrometer imaging coordinate system, scanning mirror coordinate system, satellite body coordinate system, lunar inertial system and lunar longitude and latitude coordinate system, and determine the conversion relationship between each coordinate system; S3: Based on the payload optical parameters and ray tracing method, an ideal geometric mapping model of the detector-scanning mirror-lunar surface is constructed; S4: Using the conjugate theory of reflecting prisms, determine the relationship between the scanning mirror rotation angle and the imaging spectrum field of view positioning; S5: Combine the satellite orbit, position attitude, ephemeris and detection time parameters to establish the quantitative relationship between motor angle, orbit and target longitude and latitude; S6: Integrate the satellite orbit model, the coordinate system conversion relationship, the ideal geometric mapping model, the relationship between the scanning mirror rotation angle and the imaging spectrum field of view, and the quantitative relationship between the motor rotation angle, orbit, and target longitude and latitude to establish a motion compensation imaging model for compensating for the influence of the on-orbit motion of the imaging spectrometer; S7: Analyze the impact of on-orbit errors on the compensation imaging model under lunar circumnavigation conditions, and couple the errors into the compensation imaging model as uncertainty components.

2. The method for constructing a motion-compensated imaging model for an imaging spectrometer according to claim 1, wherein: In step S1, an orbit model of the satellite is established using six orbital parameters and a satellite toolkit, wherein the six orbital parameters include semi-major axis, eccentricity, orbit inclination, right ascension of ascending node, argument of perigee and mean anomaly.

3. The method for constructing a motion-compensated imaging model for an imaging spectrometer according to claim 1, wherein: In step S2, according to the law of reflection, the scanning mirror rotation angle θ is established. s The relationship between the angle change φ of the reflected light direction satisfies φ=2θ s Based on the focal length f of the imaging spectrometer, the height H of the observation track, and the scanning field of view, the geometric relationship between the scanning mirror rotation angle and the ground target point positioning offset Δx is established, where: Δx=2Htanθ s Combining the above relationships, the scanning mirror rotation angle θ is constructed s A quantitative model for positioning the field of view of an imaging spectrometer is used to achieve high-precision scanning and positioning of the target area.

4. The method for constructing a motion-compensated imaging model for an imaging spectrometer according to claim 1, wherein: In step S3, the construction of the ideal geometric mapping model includes determining the light transmission path of the load end.

5. The method for constructing a motion-compensated imaging model for an imaging spectrometer according to claim 1, wherein: The step S5 also includes simulating the coverage area of ​​motion-compensated push-broom imaging by taking into account the payload imaging time, motion-compensated scanning angle, and the satellite's on-orbit position and attitude.

6. The method for constructing a motion-compensated imaging model for an imaging spectrometer according to claim 1, wherein: In step S7, the on-orbit errors analyzed include one or more of the following: instrument and reflection mechanism installation error, reflection mechanism stability and accuracy error, refrigerator vibration error, orbit drift error, and measurement track error.

7. The method for constructing a motion-compensated imaging model for an imaging spectrometer according to claim 6, wherein: For errors that can be accurately measured, the error parameters are measured through a reference mirror, grating encoder or theodolite, and the compensation imaging model is corrected accordingly; for errors that cannot be accurately measured, they are coupled into the compensation imaging model as uncertainty components based on the error distribution characteristics.

8. A motion-compensated imaging model for an imaging spectrometer constructed based on the method according to any one of claims 1 to 7, characterized in that: The model includes an orbit model, a coordinate system transformation relationship, an ideal geometric mapping model, a scanning mirror rotation angle and imaging spectrum field positioning relationship, a motor angle-orbit-target longitude and latitude quantization relationship, and a compensation imaging model coupled with error uncertainty components.

9. A device for implementing the method according to any one of claims 1 to 7, characterized in that: include: processor; memory for storing computer programs; Wherein, when the processor executes the computer program, the method steps described in any one of claims 1 to 7 are implemented.

Images