Energy and polarization information fused fixed star detection capability improving method

Abstract

The invention discloses a fixed star detection capability improving method fusing energy and polarization information, and belongs to the technical field of star sensor detection. In order to solve the problem that a near-earth space all-day star sensor is insufficient in fixed star detection capability in a strong atmospheric background stray light interference environment, the method comprises the following steps: exposing the sky once by using a star sensor integrated with a focal plane micro-polarizer array to obtain four gray star maps; calculating a polarization degree calculation value to obtain a polarization degree star map, and determining the sky background polarization degree; setting a polarization degree segmentation threshold value; performing threshold segmentation on the polarization degree star map to obtain a polarization degree star map segmentation result; determining a weight coefficient according to the radiation energy ratio of the fixed star to the sky background; and comparing the sky background polarization degrees, and performing weighting processing on the gray star map or the accumulated star map with the highest signal-to-noise ratio based on different conditions to obtain a final processed high-signal-to-noise-ratio star map. According to the invention, the fixed star detection capability is effectively improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of star sensor detection, and in particular relates to a method for improving star detection capability by fusing energy and polarization information. Background Art

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

[0003] To improve the detection capability of faint stellar targets, star sensor technology has seen the emergence of spectral filtering, polarization filtering, and multi-frame accumulation techniques. Spectral filtering analyzes the spectral differences between the peak radiant energy of the star target and the sky background to identify the most suitable wavelength for star observation. For near-Earth space all-day star sensors, this typically uses an InGaAs detector with a response band of 0.9μm to 1.7μm, and employs spectral filters to further restrict the response band to the I-band, J-band, or H-band, which includes the atmospheric window. Polarization filtering, based on the physical differences in polarization properties between stars and the sky background, typically employs a linear polarizer with a rotating mechanism installed at the forefront of the star sensor's optical system. The polarization filter's transmission direction is adjusted according to the sky polarization angle to suppress the sky background light. In recent years, split-focal plane polarization technology has attracted considerable attention due to its ease of operation and lack of collimation errors. The multi-frame accumulation technology utilizes the difference in the superposition rules of signals and noise. It improves the signal-to-noise ratio of the star image by performing attitude alignment and energy superposition on the multi-frame star images obtained by continuous exposure of the star sensor.

[0004] Current near-Earth space all-day star sensors primarily use energy detection mode. Polarization filtering technology fails to fully utilize polarization information, and the mechanical structure of rotating polarizers is complex, increasing the size and weight of the star sensing system. Multi-frame accumulation technology is limited by multiple exposures and is prone to introducing attitude registration errors. Furthermore, dynamic scenes require attitude assistance from inertial navigation equipment, which is complex to process. Summary of the Invention

[0005] The problem to be solved by the present invention is the insufficient star detection capability of the near-Earth space all-day star sensor under the interference of strong atmospheric background stray light. A method for improving the star detection capability by integrating energy and polarization information is proposed.

[0006] To achieve the above object, the present invention is implemented through the following technical solutions:

[0007] A method for improving star detection capabilities by integrating energy and polarization information comprises the following steps:

[0008] S1. Build a star sensor with an integrated split-focal-plane micro-polarizer array. Then, use the star sensor with an integrated split-focal-plane micro-polarizer array to obtain four grayscale star images from a single exposure of the sky.

[0009] S2. Calculate the polarization value using the four grayscale star images obtained in step S1 to obtain the polarization star map and determine the sky background polarization;

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

[0011] S4 based on the polarization threshold value obtained in step S3 polarization star map threshold segmentation, obtain polarization star map segmentation results;

[0012] S5. Determine the weighting factor based on the ratio of the radiant energy of the star to the sky background;

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

[0014] S7. When the sky background polarization degree is less than 0.75, superimpose the four grayscale star images to obtain a cumulative star image, initially improving the signal-to-noise ratio of the star image. Perform weighted processing on the cumulative star image based on the weight coefficients obtained in step S5 and the polarization star image segmentation results to obtain a final processed star image with a high signal-to-noise ratio.

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

[0016] S1.1. Build a star sensor with an integrated focal plane micropolarizer array, including a detector, a focal plane array, a micropolarizer array, an optical system, a filter, and a light shield. The detector, focal plane array, micropolarizer array, optical system, filter, and light shield are connected in sequence. The micropolarizer array is arranged in the order of transmission and polarization. 、 、 and The star sensor is composed of alternating sub-wavelength metal gratings, the position and size of each sub-wavelength metal grating strictly correspond to the position and size of the pixel of the focal plane array of the star sensor, and every four sub-wavelength metal gratings with different transmission and polarization directions constitute a 2×2 pixel super pixel. The star sensor with integrated sub-focal plane micro-polarizer array operates in the SWIR band;

[0017] S1.2. The effect of the micropolarizer on light can be expressed using the Mueller matrix, yielding the following expression:

[0018]

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

[0020] S1.3. Using a star sensor with an integrated split-focal plane micro-polarizer array, four grayscale star images are obtained by a single exposure of the sky, including the transmission and polarization directions. The grayscale star map of the sky background light and the transmission direction of the micro-polarizer are The grayscale star map of the sky background light and the transmission direction of the micro-polarizer are The grayscale star map and transmission direction of the micro-polarizer for the sky background light are Grayscale star map of the sky background light with a micro-polarizer;

[0021] Set the transmittance of each set of micro-polarizers to the sky background light as:

[0022]

[0023]

[0024]

[0025]

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

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

[0028]

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

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

[0031]

[0032] in, is the polarization degree segmentation threshold, is the mean value of the polarization star map, is the standard deviation of the polarization star map noise.

[0033] Furthermore, in step S4, for the polarization star map, the polarization calculation value is satisfied. For pixels of , the polarization degree star map is segmented by replacing the calculated polarization degree value with the mean value of the polarization degree star map, and the remaining pixels remain unchanged.

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

[0035]

[0036] Among them, k is the weight coefficient; is the first empirical parameter; is the second empirical parameter; is the stellar radiation energy received by the star sensor during the exposure time; is the sky background radiation energy received by the star sensor during the exposure time; exp is an exponential function.

[0037] Furthermore, the specific process of weighted processing in step S6 is to use the weight coefficient k as an exponent, perform k-th power operation on the value of each pixel in the polarization star map segmentation result, obtain a weighted template, and multiply the weighted template with the star map to be processed to complete the weighted processing.

[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, is the signal-to-noise ratio of the grayscale star image with the highest signal-to-noise ratio, The signal-to-noise ratio of the star image detected by the near-Earth space all-day star sensor without polarization filtering technology under the same observation conditions is: The deviation angle of the polarizer transmission direction is aligned with the deviation angle.

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

[0042]

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

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

[0045]

[0046] in, is the comprehensive improvement factor of the stellar signal-to-noise ratio, is the number of photoelectrons generated by the sky background on the detector image plane, is the number of photoelectrons generated by the star signal on the detector image plane.

[0047] Beneficial effects of the present invention:

[0048] The present invention discloses a method for improving star detection capabilities by integrating energy and polarization information. This method addresses the insufficient star detection capabilities of existing near-Earth space all-day star sensors. By using a SWIR-band focal plane polarization camera as the detection device and accumulating multiple star images, the method effectively improves the signal-to-noise ratio of the star image without slowing down the star image update rate.

[0049] The present invention discloses a method for improving 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 sky background in polarization star maps and fusing weighted polarization star maps with grayscale star maps, the signal-to-noise ratio of the star maps is further improved.

[0050] The present invention discloses a method for improving star detection capabilities by integrating energy and polarization information. By analyzing the background polarization values ​​of the observed sky area and combining two star map processing methods for different observation environments, the method effectively improves star detection capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 This is a flow chart of a method for improving stellar detection capabilities by integrating energy and polarization information according to the present invention;

[0052] Figure 2 Schematic diagram of the transmittance relationship of each superpixel group to polarized light in the imaging mode of the split-focus plane polarization detector used in the present invention;

[0053] Figure 3 This is a graph showing how the star image signal-to-noise ratio improvement factor changes with the weight coefficient k under different ratios of star energy relative to the sky background energy in the present invention;

[0054] Figure 4 Schematic diagram of a star sensor integrated with a split-focal plane micro-polarizer array in the present invention. DETAILED DESCRIPTION

[0055] In order to make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is 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 intended to explain the present invention and are not intended to limit the present invention. That is, the specific embodiments described herein are only some embodiments of the present invention, not all embodiments. Generally, the components of the specific embodiments of the present invention described and illustrated in the drawings herein can be arranged and designed in various different configurations, and the present invention can also have other embodiments.

[0056] Therefore, the following detailed description of the specific embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but is merely representative of selected specific embodiments of the present invention. All other specific embodiments obtained by those skilled in the art based on the specific embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0057] In order to further understand the content, features and effects of the present invention, the following specific embodiments are given as examples, and the attached Figure 1 -Attached Figure 4 The detailed instructions are as follows:

[0058] Example 1:

[0059] A method for improving star detection capabilities by integrating energy and polarization information comprises the following steps:

[0060] S1. Build a star sensor with an integrated split-focal-plane micro-polarizer array. Then, use the star sensor with an integrated split-focal-plane micro-polarizer array to obtain four grayscale star images from a single exposure of the sky.

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

[0062] S1.1. Build a star sensor with an integrated focal plane micropolarizer array, including a detector, a focal plane array, a micropolarizer array, an optical system, a filter, and a light shield. The detector, focal plane array, micropolarizer array, optical system, filter, and light shield are connected in sequence. The micropolarizer array is arranged in the order of transmission and polarization. 、 、 and The star sensor is composed of alternating sub-wavelength metal gratings, the position and size of each sub-wavelength metal grating strictly correspond to the position and size of the pixel of the focal plane array of the star sensor, and every four sub-wavelength metal gratings with different transmission and polarization directions constitute a 2×2 pixel super pixel. The star sensor with integrated sub-focal plane micro-polarizer array operates in the SWIR band;

[0063] S1.2. The effect of the micropolarizer on light can be expressed using the Mueller matrix, yielding the following expression:

[0064]

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

[0066] S1.3. Using a star sensor with an integrated split-focal plane micro-polarizer array, four grayscale star images are obtained by a single exposure of the sky, including the transmission and polarization directions. The grayscale star map of the sky background light and the transmission direction of the micro-polarizer are The grayscale star map of the sky background light and the transmission direction of the micro-polarizer are The grayscale star map and transmission direction of the micro-polarizer for the sky background light are Grayscale star map of the sky background light with a micro-polarizer;

[0067] Set the transmittance of each set of micro-polarizers to the sky background light as:

[0068]

[0069]

[0070]

[0071]

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

[0073] S2. Calculate the polarization value using the four grayscale star images obtained in step S1 to obtain the polarization star map and determine the sky background polarization;

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

[0075]

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

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

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

[0079]

[0080] in, is the polarization degree segmentation threshold, is the mean value of the polarization star map, is the standard deviation of the polarization star map noise.

[0081] S4 based on the polarization threshold value obtained in step S3 polarization star map threshold segmentation, obtain polarization star map segmentation results;

[0082] Furthermore, in step S4, for the polarization star map, the polarization calculation value is satisfied. For pixels of , the polarization degree star map is segmented by replacing the calculated polarization degree value with the mean value of the polarization degree star map, and the remaining pixels remain unchanged.

[0083] S5. Determine the weighting factor based on the ratio of the radiant energy of the star to the sky background;

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

[0085]

[0086] Among them, k is the weight coefficient; is the first empirical parameter; is the second empirical parameter; is the stellar radiation energy received by the star sensor during the exposure time; is the sky background radiation energy received by the star sensor during the exposure time; exp is an exponential function.

[0087] S6. When the sky background polarization degree is greater than or equal to 0.75, weighted processing is performed on the grayscale star image with the highest polarization signal-to-noise ratio based on the weight coefficient obtained in step S5 and the polarization star image segmentation result to obtain a final processed high signal-to-noise ratio star image.

[0088] Furthermore, the specific process of weighted processing in step S6 is to use the weight coefficient k as an exponent, perform k-th power operation on the value of each pixel in the polarization star map segmentation result, obtain a weighted template, and multiply the weighted template with the star map to be processed to complete the weighted processing.

[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, is the signal-to-noise ratio of the grayscale star image with the highest signal-to-noise ratio, The signal-to-noise ratio of the star image detected by the near-Earth space all-day star sensor without polarization filtering technology under the same observation conditions is: The deviation angle of the polarizer transmission direction is aligned with the deviation angle.

[0092] S7. When the sky background polarization degree is less than 0.75, superimpose the four grayscale star images to obtain a cumulative star image, initially improving the signal-to-noise ratio of the star image. Perform weighted processing on the cumulative star image based on the weight coefficients obtained in step S5 and the polarization star image segmentation results to obtain a final processed star image with a high signal-to-noise ratio.

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

[0094]

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

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

[0097]

[0098] in, is the comprehensive improvement factor of the stellar signal-to-noise ratio, is the number of photoelectrons generated by the sky background on the detector image plane, is the number of photoelectrons generated by the star signal on the detector image plane.

[0099] In summary, this embodiment is a new image processing method. Based on the focal plane star imaging technology, it fully considers the radiant energy and polarization distribution of stars and the sky background, fully utilizes the information of the electromagnetic wave energy dimension and polarization dimension, and effectively improves the star detection capability in the scene of atmospheric background stray light interference. It can provide an effective reference for the performance analysis and system design of all-day star sensors in near-Earth space.

[0100] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

[0101] Although the present application has been described above with reference to specific embodiments, various modifications may be made thereto and components may be substituted with equivalents without departing from the scope of the present application. In particular, as long as there are no structural conflicts, the various features of the embodiments disclosed herein may be combined with each other in any manner, and the omission of an exhaustive description of these combinations in this specification is solely for the sake of space and resource conservation. Therefore, the present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions within the scope of the claims.

Claims

1. A method for improving star detection capabilities by integrating energy and polarization information, characterized in that: The steps include: S1. Build a star sensor with an integrated split-focal-plane micro-polarizer array. Then, use the star sensor with an integrated split-focal-plane micro-polarizer array to obtain four grayscale star images from a single exposure of the sky. S2. Calculate the polarization value using the four grayscale star images obtained in step S1 to obtain the polarization star map and determine the sky background polarization; S3 based on the polarization star map obtained in step S2 set the polarization segmentation threshold; S4 based on the polarization threshold value obtained in step S3 polarization star map threshold segmentation, obtain polarization star map segmentation results; S5. Determine the weighting factor based on the ratio of the radiant energy of the star to the sky background; S6. When the sky background polarization degree is greater than or equal to 0.75, weighted processing is performed on the grayscale star image with the highest polarization signal-to-noise ratio based on the weight coefficient obtained in step S5 and the polarization star map segmentation result to obtain the final processed high signal-to-noise ratio star image; S7. When the sky background polarization degree is less than 0.75, superimpose the four grayscale star images to obtain a cumulative star image, initially improving the signal-to-noise ratio of the star image. Perform weighted processing on the cumulative star image based on the weight coefficients obtained in step S5 and the polarization star image segmentation results to obtain a final processed star image with a high signal-to-noise ratio.

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

1. Build a star sensor with an integrated focal plane micropolarizer array, including a detector, a focal plane array, a micropolarizer array, an optical system, a filter, and a light shield. The detector, focal plane array, micropolarizer array, optical system, filter, and light shield are connected in sequence. The micropolarizer array is arranged in the order of transmission and polarization. 、 、 and The star sensor is composed of alternating sub-wavelength metal gratings, the position and size of each sub-wavelength metal grating strictly correspond to the position and size of the pixel of the focal plane array of the star sensor, and every four sub-wavelength metal gratings with different transmission and polarization directions constitute a 2×2 pixel super pixel. The star sensor with integrated sub-focal plane micro-polarizer array operates in the SWIR band; S1.

2. The effect of the micropolarizer on light can be expressed using the Mueller matrix, yielding the following expression: Where M is the Mueller matrix, is the transmittance of the micropolarizer in the polarization direction, is the transmittance of the micro-polarizer in the direction perpendicular to the polarization direction. is the extinction ratio of the micropolarizer, is the angle between the polarization direction of the micropolarizer and the reference direction, is the optical transmittance of the micropolarizer; S1.

3. Using a star sensor with an integrated split-focal plane micro-polarizer array, four grayscale star images are obtained by a single exposure of the sky, including the transmission and polarization directions. The grayscale star map of the sky background light and the transmission direction of the micro-polarizer are The grayscale star map of the sky background light and the transmission direction of the micro-polarizer are The grayscale star map and transmission direction of the micro-polarizer for the sky background light are Grayscale star map of the sky background light with a micro-polarizer; Set the transmittance of each set of micro-polarizers to the sky background light as: in, The transmission direction is The transmittance of the micro-polarizer to the sky background light, is the sky background polarization, is the polarization angle of the skylight relative to the local meridian, The transmission direction is The angle between the transmission direction of the micro-polarizer and the local meridian, The transmission direction is The transmittance of the micro-polarizer to the sky background light, The transmission direction is The transmittance of the micro-polarizer to the sky background light, The transmission direction is The transmittance of the micro-polarizer to the sky background light.

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

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

5. The method for improving star detection capability by integrating energy and polarization information according to claim 4, characterized in that: In step S4, for the polarization star map, the polarization calculation value is satisfied. For pixels of , the polarization degree star map is segmented by replacing the calculated polarization degree value with the mean value of the polarization degree star map, and the remaining pixels remain unchanged.

6. The method for improving star detection capability by integrating energy and polarization information according to claim 5, characterized in that: The relationship between the weight coefficient k value and the ratio of the radiant energy of the star and the sky background in step S5 is: Among them, k is the weight coefficient; is the first empirical parameter; is the second empirical parameter; is the stellar radiation energy received by the star sensor during the exposure time; is the sky background radiation energy received by the star sensor during the exposure time; exp is an exponential function.

7. The method for improving star detection capability by integrating energy and polarization information according to claim 6, characterized in that: The specific process of weighted processing in step S6 is to use the weight coefficient k as an exponent, perform k-th power operation on the value of each pixel in the polarization star map segmentation result, obtain a weighted template, and multiply the weighted template with the star map to be processed to complete the weighted processing.

8. The method for improving star detection capability by integrating 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, is the signal-to-noise ratio of the grayscale star image with the highest signal-to-noise ratio, The signal-to-noise ratio of the star image detected by the near-Earth space all-day star sensor without polarization filtering technology under the same observation conditions is: The deviation angle of the polarizer transmission direction is aligned with the deviation angle.

9. The method for improving star detection capability by integrating energy and polarization information according to claim 8, characterized in that: In step S7, the four grayscale star images are superimposed to obtain a cumulative star image. The signal-to-noise ratio of the cumulative star image is: in, is the signal-to-noise ratio of the accumulated star map.

10. The method for improving star detection capability by integrating energy and polarization information according to claim 9, characterized in that: The comprehensive improvement factor of the stellar signal-to-noise ratio of the final high signal-to-noise ratio star image after processing is: in, is the comprehensive improvement factor of the stellar signal-to-noise ratio, is the number of photoelectrons generated by the sky background on the detector image plane, is the number of photoelectrons generated by the star signal on the detector image plane.

Images