A method for improving star detection capability by fusing energy and polarization information

Abstract

The application discloses a method for improving star detection capability by fusing energy and polarization information, and belongs to the technical field of star sensor detection. In order to solve the problem of insufficient star detection capability of a near-earth space all-time star sensor in a strong atmospheric background light interference environment, the star sensor integrated with a micro-polarization plate array is used to obtain four gray star images through one-time exposure of the sky; a polarization degree calculation value is calculated to obtain a polarization degree star image and determine a sky background polarization degree; a polarization degree segmentation threshold is set; the polarization degree star image is subjected to threshold segmentation to obtain a polarization degree star image segmentation result; a weight coefficient is determined according to the ratio of the radiant energy of the star and the sky background; the sky background polarization degree is compared, and the gray star image or the accumulated star image with the highest signal-to-noise ratio is subjected to weighted processing based on different conditions to obtain a final high signal-to-noise ratio star image after processing. The star detection capability is effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of star sensor detection technology, specifically relating to a method for enhancing star detection capabilities by fusing energy and polarization information. Background Technology

[0002] A star sensor is a high-precision attitude measurement device that uses a celestial reference frame as a reference and stars as the detection target. Through star image capture, image processing, star point extraction, and star image matching, it calculates the attitude of the carrier relative to inertial space, providing high-precision attitude information for spacecraft systems such as satellites and spacecraft. As an optical observation device, the star sensor is highly sensitive to background stray light levels. When applied to near-Earth space platforms such as tanks, aircraft, and ships, the strong atmospheric background radiation during the day can drown out faint stars in background noise, severely limiting the attitude determination accuracy and reliability of the star sensor.

[0003] To improve the detection capability of faint stars, spectral filtering, polarization filtering, and multi-frame accumulation techniques have emerged in the field of star sensor technology. Spectral filtering analyzes the spectral differences between the peak radiant energy of a star and the background radiation to find the most suitable wavelength for stargazing. For near-Earth space all-weather star sensors, InGaAs detectors with a response band of 0.9μm to 1.7μm are typically used, and spectral filters are employed to further restrict the response band to the I, J, or H bands, which include atmospheric windows. Polarization filtering, based on the physical characteristic of the difference in polarization between stars and the background radiation, typically involves mounting a linear polarizer with a rotating mechanism at the front of the star sensor's optical system and adjusting the polarization direction of the polarizer according to the sky's polarization angle to suppress background light. In recent years, focal plane polarization technology has attracted considerable attention due to its ease of operation and lack of alignment errors. Multi-frame accumulation technology utilizes the difference in the superposition rules of signal and noise. By continuously exposing multiple star images with a star sensor, attitude registration and energy superposition are performed to improve the signal-to-noise ratio of the star image.

[0004] Current near-Earth space all-weather star sensors primarily employ energy detection mode. Polarization filtering technology fails to fully utilize all polarization information, and the complex mechanical structure of rotating polarizers increases the size and weight of the star sensing system. Multi-frame accumulation technology is limited by multiple exposures, easily introducing attitude registration errors, and requires inertial navigation equipment for attitude assistance in dynamic scenes, making the processing technology complex. Summary of the Invention

[0005] The problem this invention aims to solve is the insufficient star detection capability of near-Earth space all-weather star sensors under strong atmospheric background stray light interference. It proposes a method to enhance star detection capability by fusing energy and polarization information.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for enhancing stellar detection capabilities by integrating energy and polarization information includes the following steps:

[0008] S1. Construct a star sensor with an integrated focal plane micro-polarizer array, and then use the star sensor with the integrated focal plane micro-polarizer array to take a single exposure of the sky to obtain four grayscale star images;

[0009] S2. Calculate the polarization degree using the four grayscale star images obtained in step S1, obtain the polarization degree star image, and determine the polarization degree of the sky background.

[0010] S3. Set the polarization degree segmentation threshold based on the polarization degree star map obtained in step S2;

[0011] S4. Based on the polarization degree segmentation threshold obtained in step S3, perform threshold segmentation on the polarization degree star map to obtain the polarization degree star map segmentation result;

[0012] S5. Determine the weighting coefficients based on the ratio of radiant energy of stars to that of the background sky;

[0013] S6. When the polarization degree of the sky background is greater than or equal to 0.75, the grayscale star map with the highest polarization signal-to-noise ratio is weighted based on the weight coefficients obtained in step S5 and the polarization degree star map segmentation results to obtain the final high signal-to-noise ratio star map after processing.

[0014] S7. When the polarization degree of the sky background is less than 0.75, the four grayscale star images are superimposed to obtain an accumulated star image, which initially improves the signal-to-noise ratio of the star image. Based on the weight coefficients obtained in step S5 and the polarization degree star image segmentation results, the accumulated star image is weighted to obtain the final high signal-to-noise ratio star image.

[0015] Furthermore, the specific implementation method of step S1 includes the following steps:

[0016] S1.1. Construct a star sensor with an integrated focal plane micro-polarizer array, including a detector, a focal plane array, a micro-polarizer array, an optical system, a filter, and a light shield. The detector, focal plane array, micro-polarizer array, optical system, filter, and light shield are connected sequentially. The micro-polarizer array is arranged in the following order from the transmission direction: , , and The star sensor is composed of alternating subwavelength metal gratings. The position and size of each subwavelength metal grating strictly correspond to the position and size of the pixels in the focal plane array of the star sensor. Every four subwavelength metal gratings with different polarization directions constitute a 2×2 pixel superpixel. The star sensor with the integrated focal plane micro-polarizer array operates in the SWIR band.

[0017] S1.2. The effect of the micro-polarizer on light is represented by the Mueller matrix, resulting in the following expression:

[0018]

[0019] Where M is the Mueller matrix, It refers to the transmittance in the polarization direction of the micro-polarizer. It is the transmittance in the direction perpendicular to the polarization direction of the micro-polarizer. It is the extinction ratio of the micropolarizer. It is the angle between the transmission direction of the micropolarizer and the reference direction. It is the optical transmittance of the micro-polarizer;

[0020] S1.3. Using a star sensor with an integrated focal plane micro-polarizer array, four grayscale star images were obtained from a single exposure of the sky, including images with the polarization direction as... The micro-polarizer's grayscale star map of the sky background light, with the polarization direction as follows: The micro-polarizer's grayscale star map of the sky background light, with the polarization direction as follows: The micro-polarizer provides a grayscale star map of the sky background light and the polarization direction. The grayscale star map of the sky background light obtained by the micro-polarizer;

[0021] The transmittance of each group of micropolarizers for the background sky light is set as follows:

[0022]

[0023]

[0024]

[0025]

[0026] in, For the direction of penetration is The transmittance of the micropolarizer to the background light of the sky. The polarization degree of the sky background. The polarization angle of skylight relative to the local meridian. For the direction of penetration is The angle between the transmission direction of the micropolarizer and the local meridian. For the direction of penetration is The transmittance of the micropolarizer to the background light of the sky. For the direction of penetration is The transmittance of the micropolarizer to the background light of the sky. For the direction of penetration is The transmittance of the micro-polarizer to the background light of the sky.

[0027] Furthermore, the specific process for calculating the degree of polarization in step S2 is as follows:

[0028]

[0029] Where i is the row number of any row in the polarization degree star chart; j is the column number of any column in the polarization degree star chart; This represents the calculated polarization degree of the pixel in the i-th row and j-th column of the polarization degree star map. Indicates the corresponding polarization direction is The number of photoelectrons received by a pixel behind a micropolarizer; Indicates the corresponding polarization direction is The number of photoelectrons received by a pixel behind a micropolarizer; Indicates the corresponding polarization direction is The number of photoelectrons received by a pixel behind a micropolarizer; Indicates the corresponding polarization direction is The number of photoelectrons received by the pixel behind the micropolarizer; the polarization degree of the sky background is obtained by averaging the polarization degree values ​​of all pixels in the polarization degree star map.

[0030] Furthermore, step S3 determines the polarization degree segmentation threshold based on the polarization degree star map obtained in step S2, with the following expression:

[0031]

[0032] in, The polarization degree segmentation threshold, This represents the mean value of the polarization degree star chart. This represents the standard deviation of the polarization degree star map noise.

[0033] Furthermore, in step S4, the polarization degree calculated value is satisfied for the polarization degree star diagram. For the pixels, the mean value of the polarization degree star map is used to replace the calculated polarization degree value, while the remaining pixels remain unchanged, to obtain the polarization degree star map segmentation result.

[0034] Furthermore, the relationship between the weighting coefficient k value and the ratio of the radiant energy of the star and the sky background in step S5 is as follows:

[0035]

[0036] Where k is the weighting coefficient; This is the first empirical parameter; This is the second empirical parameter; It is the stellar radiation energy received by the star sensor during its exposure time; It is the background radiation energy of the sky received by the star sensor during the exposure time; exp is an exponential function.

[0037] Furthermore, the specific process of weighting in step S6 is as follows: using the weight coefficient k as the exponent, the value of each pixel in the polarization degree star map segmentation result is raised to the power of k to obtain the weighted template. The weighted template is then multiplied with the star map to be processed to complete the weighting process.

[0038] Furthermore, the signal-to-noise ratio of the grayscale star image with the highest signal-to-noise ratio in step S6 is:

[0039]

[0040] in, This represents the signal-to-noise ratio (SNR) of the grayscale star image with the highest SNR. To improve the signal-to-noise ratio of star charts for near-Earth space all-weather star sensors without polarization filtering under the same observation conditions. The deviation angle is used to align the polarizer's transmission direction.

[0041] Furthermore, in step S7, the four grayscale star images are superimposed to obtain an accumulated star image. The signal-to-noise ratio of the accumulated star image is:

[0042]

[0043] in, This is the signal-to-noise ratio of the accumulated star chart.

[0044] Furthermore, the overall enhancement factor of the stellar signal-to-noise ratio for the final high signal-to-noise ratio star map obtained after processing is:

[0045]

[0046] in, This represents the overall improvement factor for the signal-to-noise ratio of stars. The number of photoelectrons generated by the sky background on the detector's image plane. This represents the number of photoelectrons generated by the stellar signal on the detector's image plane.

[0047] The beneficial effects of this invention are:

[0048] The present invention describes a method for enhancing star detection capabilities by fusing energy and polarization information. Addressing the problem of insufficient star detection capabilities of existing near-Earth space all-day star sensors, this method uses a SWIR-band focal plane polarization camera as the detection device and effectively improves the signal-to-noise ratio of star images by accumulating multiple star images without slowing down the star image update rate.

[0049] The present invention provides a method for enhancing star detection capabilities by fusing energy and polarization information. This method addresses the problem of insufficient star detection capabilities of existing near-Earth space all-day star sensors by analyzing the distribution patterns of stars and the sky background in the polarization degree star map and further improving the signal-to-noise ratio of the star map through image fusion of the weighted polarization degree star map and the grayscale star map.

[0050] The present invention describes a method for enhancing star detection capabilities by integrating energy and polarization information. By analyzing the background polarization degree values ​​of the observed sky region, the method combines two star map processing methods for different observation environments, effectively improving star detection capabilities. Attached Figure Description

[0051] Figure 1 This is a flowchart of a method for enhancing star detection capabilities by fusing energy and polarization information, as described in this invention.

[0052] Figure 2 This is a schematic diagram showing the transmittance relationship of each superpixel to polarized light under the imaging method of a split-focus plane polarization detector in this invention.

[0053] Figure 3 This is a graph showing the variation of the star map signal-to-noise ratio enhancement factor with the weighting coefficient k under different proportions of stars relative to the sky background energy in this invention.

[0054] Figure 4 This is a schematic diagram of the star sensor with an integrated focal plane micro-polarizer array in this invention. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described specific embodiments are merely a part of the embodiments of the invention, and not all of them. The components of the specific embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations, and the invention may also have other embodiments.

[0056] Therefore, the following detailed description of specific embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected specific embodiments of the invention. All other specific embodiments obtained by those skilled in the art based on these specific embodiments without inventive effort are within the scope of protection of this invention.

[0057] To further understand the invention's content, features, and effects, the following specific embodiments are provided, along with accompanying drawings. Figure 1 -Appendix Figure 4 Detailed explanation is as follows:

[0058] Example 1:

[0059] A method for enhancing stellar detection capabilities by integrating energy and polarization information includes the following steps:

[0060] S1. Construct a star sensor with an integrated focal plane micro-polarizer array, and then use the star sensor with the integrated focal plane micro-polarizer array to take a single exposure of the sky to obtain four grayscale star images;

[0061] Furthermore, the specific implementation method of step S1 includes the following steps:

[0062] S1.1. Construct a star sensor with an integrated focal plane micro-polarizer array, including a detector, a focal plane array, a micro-polarizer array, an optical system, a filter, and a light shield. The detector, focal plane array, micro-polarizer array, optical system, filter, and light shield are connected sequentially. The micro-polarizer array is arranged in the following order from the transmission direction: , , and The star sensor is composed of alternating subwavelength metal gratings. The position and size of each subwavelength metal grating strictly correspond to the position and size of the pixels in the focal plane array of the star sensor. Every four subwavelength metal gratings with different polarization directions constitute a 2×2 pixel superpixel. The star sensor with the integrated focal plane micro-polarizer array operates in the SWIR band.

[0063] S1.2. The effect of the micro-polarizer on light is represented by the Mueller matrix, resulting in the following expression:

[0064]

[0065] Where M is the Mueller matrix, It refers to the transmittance in the polarization direction of the micro-polarizer. It is the transmittance in the direction perpendicular to the polarization direction of the micro-polarizer. It is the extinction ratio of the micropolarizer. It is the angle between the transmission direction of the micropolarizer and the reference direction. It is the optical transmittance of the micro-polarizer;

[0066] S1.3. Using a star sensor with an integrated focal plane micro-polarizer array, four grayscale star images were obtained from a single exposure of the sky, including images with the polarization direction as... The micro-polarizer's grayscale star map of the sky background light, with the polarization direction as follows: The micro-polarizer's grayscale star map of the sky background light, with the polarization direction as follows: The micro-polarizer provides a grayscale star map of the sky background light and the polarization direction. The grayscale star map of the sky background light obtained by the micro-polarizer;

[0067] The transmittance of each group of micropolarizers for the background sky light is set as follows:

[0068]

[0069]

[0070]

[0071]

[0072] in, For the direction of penetration is The transmittance of the micropolarizer to the background light of the sky. The polarization degree of the sky background. The polarization angle of skylight relative to the local meridian. For the direction of penetration is The angle between the transmission direction of the micropolarizer and the local meridian. For the direction of penetration is The transmittance of the micropolarizer to the background light of the sky. For the direction of penetration is The transmittance of the micropolarizer to the background light of the sky. For the direction of penetration is The transmittance of the micro-polarizer to the background light of the sky.

[0073] S2. Calculate the polarization degree using the four grayscale star images obtained in step S1, obtain the polarization degree star image, and determine the polarization degree of the sky background.

[0074] Furthermore, the specific process for calculating the degree of polarization in step S2 is as follows:

[0075]

[0076] Where i is the row number of any row in the polarization degree star chart; j is the column number of any column in the polarization degree star chart; This represents the calculated polarization degree of the pixel in the i-th row and j-th column of the polarization degree star map. Indicates the corresponding polarization direction is The number of photoelectrons received by a pixel behind a micropolarizer; Indicates the corresponding polarization direction is The number of photoelectrons received by a pixel behind a micropolarizer; Indicates the corresponding polarization direction is The number of photoelectrons received by a pixel behind a micropolarizer; Indicates the corresponding polarization direction is The number of photoelectrons received by a pixel behind a micropolarizer. The polarization degree of the sky background is obtained by averaging the polarization degree values ​​of all pixels in the polarization degree star map.

[0077] S3. Set the polarization degree segmentation threshold based on the polarization degree star map obtained in step S2;

[0078] Furthermore, step S3 determines the polarization degree segmentation threshold based on the polarization degree star map obtained in step S2, with the following expression:

[0079]

[0080] in, The polarization degree segmentation threshold, This represents the mean value of the polarization degree star chart. This represents the standard deviation of the polarization degree star map noise.

[0081] S4. Based on the polarization degree segmentation threshold obtained in step S3, perform threshold segmentation on the polarization degree star map to obtain the polarization degree star map segmentation result;

[0082] Furthermore, in step S4, the polarization degree calculated value is satisfied for the polarization degree star diagram. For the pixels, the mean value of the polarization degree star map is used to replace the calculated polarization degree value, while the remaining pixels remain unchanged, to obtain the polarization degree star map segmentation result.

[0083] S5. Determine the weighting coefficients based on the ratio of radiant energy of stars to that of the background sky;

[0084] Furthermore, the relationship between the weighting coefficient k value and the ratio of the radiant energy of the star and the sky background in step S5 is as follows:

[0085]

[0086] Where k is the weighting coefficient; This is the first empirical parameter; This is the second empirical parameter; It is the stellar radiation energy received by the star sensor during its exposure time; It is the background radiation energy of the sky received by the star sensor during the exposure time; exp is an exponential function.

[0087] S6. When the polarization degree of the sky background is greater than or equal to 0.75, the grayscale star map with the highest polarization signal-to-noise ratio is weighted based on the weight coefficients obtained in step S5 and the polarization degree star map segmentation results to obtain the final high signal-to-noise ratio star map after processing.

[0088] Furthermore, the specific process of weighting in step S6 is as follows: using the weight coefficient k as the exponent, the value of each pixel in the polarization degree star map segmentation result is raised to the power of k to obtain the weighted template. The weighted template is then multiplied with the star map to be processed to complete the weighting process.

[0089] Furthermore, the signal-to-noise ratio of the grayscale star image with the highest signal-to-noise ratio in step S6 is:

[0090]

[0091] in, This represents the signal-to-noise ratio (SNR) of the grayscale star image with the highest SNR. To improve the signal-to-noise ratio of star charts for near-Earth space all-weather star sensors without polarization filtering under the same observation conditions. The deviation angle is used to align the polarizer's transmission direction.

[0092] S7. When the polarization degree of the sky background is less than 0.75, the four grayscale star images are superimposed to obtain an accumulated star image, which initially improves the signal-to-noise ratio of the star image. Based on the weight coefficients obtained in step S5 and the polarization degree star image segmentation results, the accumulated star image is weighted to obtain the final high signal-to-noise ratio star image.

[0093] Furthermore, in step S7, the four grayscale star images are superimposed to obtain an accumulated star image. The signal-to-noise ratio of the accumulated star image is:

[0094]

[0095] in, This is the signal-to-noise ratio of the accumulated star chart.

[0096] Furthermore, the overall enhancement factor of the stellar signal-to-noise ratio for the final high signal-to-noise ratio star map obtained after processing is:

[0097]

[0098] in, This represents the overall improvement factor for the signal-to-noise ratio of stars. The number of photoelectrons generated by the sky background on the detector's image plane. This represents the number of photoelectrons generated by the stellar signal on the detector's image plane.

[0099] In summary, this embodiment is a novel image processing method that, based on focal plane stellar imaging technology, fully considers the distribution patterns of radiant energy and polarization degree of stars and the sky background. It makes full use of information from the electromagnetic wave energy dimension and polarization dimension, effectively improving the star detection capability under atmospheric background stray light interference scenarios. It can provide a valid reference for the performance analysis and system design of near-Earth space all-weather star sensors.

[0100] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0101] Although this application has been described above with reference to specific embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of this application. In particular, as long as there is no structural conflict, the features in the specific embodiments disclosed in this application can be combined with each other in any way. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, this application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for enhancing stellar detection capabilities by integrating energy and polarization information, characterized in that, Includes the following steps: S1. Construct a star sensor with an integrated focal plane micro-polarizer array, and then use the star sensor with the integrated focal plane micro-polarizer array to take a single exposure of the sky to obtain four grayscale star images; S2. Calculate the polarization degree using the four grayscale star images obtained in step S1, obtain the polarization degree star image, and determine the polarization degree of the sky background. S3. Set the polarization degree segmentation threshold based on the polarization degree star map obtained in step S2; S4. Based on the polarization degree segmentation threshold obtained in step S3, perform threshold segmentation on the polarization degree star map to obtain the polarization degree star map segmentation result; S5. Determine the weighting coefficients based on the ratio of radiant energy of stars to that of the background sky; S6. When the polarization degree of the sky background is greater than or equal to 0.75, the grayscale star map with the highest polarization signal-to-noise ratio is weighted based on the weight coefficients obtained in step S5 and the polarization degree star map segmentation results to obtain the final high signal-to-noise ratio star map after processing. S7. When the polarization degree of the sky background is less than 0.75, the four grayscale star images are superimposed to obtain an accumulated star image, which initially improves the signal-to-noise ratio of the star image. Based on the weight coefficients obtained in step S5 and the polarization degree star image segmentation results, the accumulated star image is weighted to obtain the final high signal-to-noise ratio star image.

2. The method for enhancing star detection capabilities by fusing energy and polarization information according to claim 1, characterized in that, The specific implementation method of step S1 includes the following steps: S1.

1. Construct a star sensor with an integrated focal plane micro-polarizer array, including a detector, a focal plane array, a micro-polarizer array, an optical system, a filter, and a light shield. The detector, focal plane array, micro-polarizer array, optical system, filter, and light shield are connected sequentially. The micro-polarizer array is arranged in the following order from the transmission direction: , , and The star sensor is composed of alternating subwavelength metal gratings. The position and size of each subwavelength metal grating strictly correspond to the position and size of the pixels in the focal plane array of the star sensor. Every four subwavelength metal gratings with different polarization directions constitute a 2×2 pixel superpixel. The star sensor with the integrated focal plane micro-polarizer array operates in the SWIR band. S1.

2. The effect of the micro-polarizer on light is represented by the Mueller matrix, resulting in the following expression: Where M is the Mueller matrix, It refers to the transmittance in the polarization direction of the micro-polarizer. It is the transmittance in the direction perpendicular to the polarization direction of the micro-polarizer. It is the extinction ratio of the micropolarizer. It is the angle between the transmission direction of the micropolarizer and the reference direction. It is the optical transmittance of the micro-polarizer; S1.

3. Using a star sensor with an integrated focal plane micro-polarizer array, four grayscale star images were obtained from a single exposure of the sky, including images with the polarization direction as... The micro-polarizer's grayscale star map of the sky background light, with the polarization direction as follows: The micro-polarizer's grayscale star map of the sky background light, with the polarization direction as follows: The micro-polarizer provides a grayscale star map of the sky background light and the polarization direction. The grayscale star map of the sky background light obtained by the micro-polarizer; The transmittance of each group of micropolarizers for the background sky light is set as follows: in, For the direction of penetration is The transmittance of the micropolarizer to the background light of the sky. The polarization degree of the sky background. The polarization angle of skylight relative to the local meridian. For the direction of penetration is The angle between the transmission direction of the micropolarizer and the local meridian. For the direction of penetration is The transmittance of the micropolarizer to the background light of the sky. For the direction of penetration is The transmittance of the micropolarizer to the background light of the sky. For the direction of penetration is The transmittance of the micro-polarizer to the background light of the sky.

3. The method for enhancing star detection capabilities by fusing energy and polarization information according to claim 2, characterized in that, The specific process for calculating the degree of polarization in step S2 is as follows: Where i is the row number of any row in the polarization degree star chart; j is the column number of any column in the polarization degree star chart; This is the calculated polarization degree value of the pixel in the i-th row and j-th column of the polarization degree star map; Indicates the corresponding polarization direction is The number of photoelectrons received by a pixel behind a micropolarizer; Indicates the corresponding polarization direction is The number of photoelectrons received by a pixel behind a micropolarizer; Indicates the corresponding polarization direction is The number of photoelectrons received by a pixel behind a micropolarizer; Indicates the corresponding polarization direction is The number of photoelectrons received by the pixel behind the micropolarizer; the polarization degree of the sky background is obtained by averaging the polarization degree values ​​of all pixels in the polarization degree star map.

4. The method for enhancing star detection capabilities by fusing energy and polarization information according to claim 3, characterized in that, Step S3 is based on the polarization degree segmentation threshold of the polarization degree star map obtained in step S2, and its expression is: in, The polarization degree segmentation threshold, This represents the mean value of the polarization degree star chart. This represents the standard deviation of the polarization degree star map noise.

5. The method for enhancing star detection capabilities by fusing energy and polarization information according to claim 4, characterized in that, In step S4, the polarization degree calculation value is satisfied for the polarization degree star diagram. For the pixels, the mean value of the polarization degree star map is used to replace the calculated polarization degree value, while the remaining pixels remain unchanged, to obtain the polarization degree star map segmentation result.

6. The method for enhancing star detection capabilities by fusing energy and polarization information according to claim 5, characterized in that, The relationship between the weighting coefficient k value and the ratio of stellar and sky background radiant energy in step S5 is as follows: Where k is the weighting coefficient; This is the first empirical parameter; This is the second empirical parameter; It is the stellar radiation energy received by the star sensor during its exposure time; It is the background radiation energy of the sky received by the star sensor during the exposure time; exp is an exponential function.

7. The method for enhancing star detection capabilities by fusing energy and polarization information according to claim 6, characterized in that, The specific process of weighting in step S6 is as follows: using the weight coefficient k as the exponent, the value of each pixel in the polarization degree star map segmentation result is raised to the power of k to obtain the weighted template. The weighted template is then multiplied with the star map to be processed to complete the weighting process.

8. The method for enhancing star detection capabilities by fusing energy and polarization information according to claim 7, characterized in that, The signal-to-noise ratio of the grayscale star image with the highest signal-to-noise ratio in step S6 is: in, This represents the signal-to-noise ratio (SNR) of the grayscale star image with the highest SNR. To improve the signal-to-noise ratio of star charts for near-Earth space all-weather star sensors without polarization filtering under the same observation conditions. The deviation angle is used to align the polarizer's transmission direction.

9. The method for enhancing star detection capabilities by fusing energy and polarization information according to claim 8, characterized in that, In step S7, the four grayscale star images are superimposed to obtain the accumulated star image. The signal-to-noise ratio of the accumulated star image is: in, This is the signal-to-noise ratio of the accumulated star chart.

10. The method for enhancing star detection capabilities by fusing energy and polarization information according to claim 9, characterized in that, The overall enhancement factor of the stellar signal-to-noise ratio for the final high signal-to-noise ratio star map obtained after processing is: in, This represents the overall improvement factor for the signal-to-noise ratio of stars. The number of photoelectrons generated by the sky background on the detector's image plane. This represents the number of photoelectrons generated by the stellar signal on the detector's image plane.

Images