Method for evaluating star measurement probability of star sensor
By using a star sensor probability assessment method, the problem of star probability assessment in the design of airborne star sensors was solved, enabling efficient verification and optimization of parameter design and reducing the cost of physical trial and error.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-27
- Publication Date
- 2026-04-21
AI Technical Summary
During the design phase of airborne star sensors, existing technologies struggle to effectively assess their star detection probability and parameter design, resulting in high trial-and-error costs in physical design.
A method for evaluating the probability of star detection using a star sensor is provided. This method involves generating a star library, calculating the optical axis direction, selecting a set of observable stars, conducting continuous star detection simulations, recording the number and distribution of observable stars, and evaluating the usability of the design parameters.
It enables simulation verification during the design phase, reduces physical trial and error, provides reference for parameter iterative design, and improves design efficiency.
Smart Images
Figure CN121898478A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of airborne astronomical navigation technology, and in particular to a method for evaluating the probability of star detection using a star sensor. Background Technology
[0002] Inertial / astronomical integrated navigation technology uses attitude measurements obtained from star sensors that do not drift over time to correct sensor errors in the inertial navigation system, greatly improving the accuracy of the navigation system and meeting the requirements for long-endurance navigation. It has advantages such as good concealment, high reliability, strong anti-interference ability and full autonomy, and its application in airborne platforms will become more and more widespread.
[0003] Due to the limitations of the application scenarios, airborne star sensors have a limited field of view. When measuring stars, they must be captured and put into tracking mode through servo tracking environment control. The design of its tracking range, the star measurement capability of the star sensor, and the solar avoidance angle of the optical system should meet certain navigation availability conditions, that is, to ensure that at least 2 to 3 stars (with good geometric distribution in a specific altitude area) can be observed within the tracking range for inertial attitude update calculation. Summary of the Invention
[0004] The purpose of this invention is to provide a method for evaluating the probability of star detection by a star sensor, which is used to comprehensively evaluate the design parameters of the star sensor, such as limiting magnitude, field of view, pixel size, and focal length, during the design phase, complete the preliminary simulation verification, provide a reference for the iterative design of star sensor parameters, and avoid too much trial and error investment in physical aspects during the design phase.
[0005] Summary of the present invention: According to a first aspect of the present invention, a method for evaluating the probability of star detection using a star sensor is provided, comprising the following steps: Step 1: Generate a selection library of stars based on the star sensor's limiting magnitude design value; Step 2: Set the star measurement time, location, and attitude, and calculate the optical axis pointing of the star sensor; Step 3: Based on the star sensor design parameters and optical axis orientation, further filter the observable star set S from the star library S. v The star sensor design parameters include limiting magnitude, field of view, focal length, and focal plane detector pixel size. Step 4: Set the time, location, and attitude sequence for satellite observation, perform continuous satellite observation simulation, and record the observable star set S. v The number of stars in the middle; Step 5: Statistically analyze the satellite detection probability and distribution to assess the availability of design parameters.
[0006] In one possible embodiment, step 1 specifically involves the following steps: Step 1.1: Based on the photoelectric characteristics of the star sensor focal plane detector, select a visible light star catalog or an infrared star catalog as the original star catalog; Step 1.2: Select stars in the original star catalog whose magnitude is no greater than the design value of the limit magnitude, store their star number, magnitude, right ascension, declination, proper motion, and spectral type information, and generate the selected star library S.
[0007] In one possible embodiment, step 2 specifically involves the following steps: Step 2.1: Based on the stellar observation time, convert Beijing time to Coordinated Universal Time (UTC), Earth Time, UTC, and Julian Day in sequence, calculate the Earth's rotation angle (ERA), and combine this with precession and nutation to obtain the Greenwich Mean Time (GAST) stellar perspective, thereby obtaining the coordinate transformation matrix from the inertial frame to the Earth frame. : ; Step 2.2: Calculate the coordinate transformation matrix from the Earth system to the geographic system based on the carrier's location (Lon and Lat) at the time of satellite measurement. : ; Step 2.3: Based on the heading angle of the carrier relative to the geographic system at the time of satellite measurement. Pitch angle Roll angle Using a 3-1-2 Euler angle transformation, calculate the coordinate transformation matrix from the geographic system to the carrier system. : ; Step 2.4: Based on the installation relationship between the star sensor and the carrier, obtain the coordinate transformation matrix from the carrier system to the star sensor system. ; Step 2.5: Calculate the orientation of the star sensor's optical axis in the inertial frame through coordinate transformation. : ; Step 2.6: Calculate the right ascension corresponding to the direction of the star sensor's optical axis. ra Declination dec : .
[0008] In one possible embodiment, step 3 specifically involves the following steps: Step 3.1: Based on the star sensor's field of view size Fov Calculate the equivalent circumcircle diameter of the field of view. D : ; Step 3.2: Select the set of stars S1 within the right ascension range of the star sensor's optical axis from S. The specific steps are as follows: Calculate the zenith angle of the optical axis z :
[0009] Calculate the spherical angles of the tangent meridian of the circumcircle of the field of view and the optical axis relative to the celestial north pole. ang :
[0010] Left boundary of right ascension of the field of view LeftRa and right boundary RighRat for:
[0011] The star set S1 within the right ascension range of the optical axis was selected based on the left and right boundaries. The selection criteria were: the left boundary of the right ascension of the field of view. LeftRa ≤right ascension of stars ra s ≤Right boundary of the right ascension of the field of view RighRat ; Step 3.3: Select the subset S2 of stars within the declination span of the star sensor's optical axis from the star set S1. The specific steps are as follows: Upper boundary of field of view declination TopDec and lower boundary DownDec for:
[0012] The star set S2 within the optical axis declination range was selected based on the upper and lower boundaries. The selection criteria were: lower boundary of field of view declination. DownDec ≤stellar declination dec s ≤ Upper boundary of field of view declination TopDec ; Then star set S2 is the set of stars that can theoretically enter the outer circle of the star sensor's field of view; Step 3.4: Calculate the starlight vector for each star system within star set S2. Vs The specific steps are as follows: Based on the right ascension of each star in star set S2 ra s Declination dec s Calculate the starlight vector in the inertial frame. Vi :
[0013] Transformed to a star-sensitive system, the starlight vector is obtained. Vs : ; Step 3.5: Calculate the coordinates of the star points, select the star points mapped onto the imaging array, and generate the observable star set S. v The specific steps are as follows: Based on the star sensor focal length design value f Focal plane detector pixel size PixSize Calculate the mapped coordinates of stars within the field of view. x , y :
[0014] in, x 0、 y 0 is the principal point of the imaging array, which is set as an ideal value during the design phase.
[0015] in, pixelsX , pixelsY The number of pixels in the focal plane array of the detector represents the size of the imaging array. Select the star points mapped onto the imaging array to generate an observable star set S. v The filtering criteria are: .
[0016] In one possible embodiment, in step 4, for the same satellite measurement time, a random satellite measurement location can be set, i.e., latitude and longitude values can be randomly selected globally, and the heading angle, pitch angle, and roll angle of the carrier can all be set to 0°, with the star-sensor system coinciding with the carrier system. , All are unit arrays, thus achieving random pointing of the optical axis of the star sensor across the entire celestial sphere. Extensive Monte Carlo star measurement simulation experiments were conducted, recording the observable star set S. v On the one hand, it can count the number of stars in the satellite; on the other hand, it can also compile the flight trajectory of the carrier according to the application scenario, set the corresponding satellite measurement time, location and attitude sequence, conduct continuous satellite measurement simulation, and record the number of stars.
[0017] In one possible embodiment, step 5 specifically involves the following steps: Step 5.1: Based on the number of stars and the number of simulations recorded in the continuous star measurement simulation, calculate the star measurement probability, count the observable situation of stars with different brightness, obtain the number of stars that the star sensor can observe and the weakest magnitude under the corresponding design parameters, and evaluate the theoretical star measurement capability corresponding to the design parameters. Step 5.2: In each satellite measurement simulation process, according to the measurement equations of the integrated navigation system:
[0018] By combining the azimuth and elevation angle information of each observable star, the measurement matrix is calculated. H Thus, the error covariance matrix is calculated. Q :
[0019] Where, q ij For the first i Star measurement and the first j Covariance of star measurements; Reference satellite navigation accuracy attenuation factor DOP Definition, calculation accuracy attenuation factor DOP :
[0020] DOP The smaller the value, the more uniform the geometric distribution of stars, and the smaller the astronomical positioning error measured by star information; Recording continuous satellite measurement simulation DOP The values are statistically analyzed to determine their magnitude and variation, and the distribution of stars observable by the star sensor under the corresponding design parameters is evaluated.
[0021] Step 5.3: Analyze the star detection probability and distribution of the star sensor under the corresponding design parameters, evaluate the usability of the design parameters, and use them as a reference for iterative design.
[0022] According to a second aspect of the present invention, a computer-readable storage medium is provided, comprising computer program instructions that, when executed by a computing device or processor, perform the method as described above.
[0023] According to a third aspect of the invention, a computer program product comprising instructions that, when executed by a computing device or processor, cause the computing device or processor to perform the method as described above.
[0024] The advantages and effects of this invention are: it can realize the preliminary simulation verification of airborne star sensors, provide a reference for the iterative design of star sensor parameters, and avoid too much trial and error investment in physical aspects during the design stage. Attached Figure Description
[0025] To more clearly illustrate the technical solutions implemented in this invention, a simple explanation of the accompanying drawings used in the description of this invention will be provided below. Obviously, the drawings described below are merely some embodiments of this invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.
[0026] Figure 1This is a schematic flowchart of a star sensor probability assessment method according to an embodiment of the present invention; Detailed Implementation To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0027] The features of various aspects of the embodiments of the present invention will now be described in detail. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can also be practiced without these specific details. The following description of the embodiments is merely intended to provide a better understanding of the invention by illustrating examples. The invention is not limited to any specific setups and methods provided below, but covers all improvements, substitutions, etc., to product structures and methods without departing from the spirit of the invention. In the various drawings and the following description, well-known structures and techniques are not shown to avoid unnecessarily obscuring the invention.
[0028] It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other, and the various embodiments can be referenced and cited in each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.
[0029] Figure 1 This is a schematic flowchart of a laboratory simulation satellite navigation method according to an embodiment of the present invention.
[0030] like Figure 1 As shown, the method may include the following steps: Step 1: Generate a filter star library based on the star sensor's limiting magnitude design value. The specific steps are as follows: Step 1.1: Based on the photoelectric characteristics of the star sensor focal plane detector, select a visible light star catalog or an infrared star catalog as the original star catalog.
[0031] Step 1.2: Select stars in the original star catalog whose magnitude is no greater than the design value of the limiting magnitude, store their star number, magnitude, right ascension, declination, proper motion, spectral type and other information, and generate the star library S.
[0032] Step 2: Calculate the optical axis pointing of the star sensor based on the star measurement time, location, and attitude. The specific steps are as follows: Step 2.1: Based on the specific time of the stellar measurement, convert Beijing time to Coordinated Universal Time (UTC), Earth Time, UTC, and Julian Day in sequence, calculate the Earth's rotation angle (ERA), and combine this with precession and nutation to obtain the Greenwich Mean Time (GAST) stellar perspective, thereby obtaining the coordinate transformation matrix from the inertial frame to the Earth frame. :
[0033] Step 2.2: Based on the carrier's location (Lon and Lat) at the time of satellite measurement, calculate the coordinate transformation matrix from the Earth system to the geographic system. :
[0034] Step 2.3: Based on the heading angle of the carrier relative to the geographic system at the time of satellite measurement. Pitch angle Roll angle Using a 3-1-2 Euler angle transformation, calculate the coordinate transformation matrix from the geographic system to the carrier system. :
[0035] Step 2.4: Based on the installation relationship between the star sensor and the carrier, obtain the coordinate transformation matrix from the carrier system to the star sensor system. ; Step 2.5: Calculate the orientation of the star sensor's optical axis in the inertial frame through coordinate transformation. :
[0036] Step 2.6: Calculate the right ascension corresponding to the direction of the star sensor's optical axis. ra Declination dec :
[0037] Step 3: Based on the star sensor design parameters and optical axis orientation, further filter the observable star set S from the star library S. v The specific steps are as follows: Step 3.1: Based on the star sensor field of view design values Fov Calculate the equivalent circumcircle diameter of the field of view. D :
[0038] Step 3.2: Select the set of stars S1 within the right ascension range of the star sensor's optical axis from S. The specific steps are as follows: Calculate the zenith angle of the optical axis z :
[0039] Calculate the spherical angles of the tangent meridian of the circumcircle of the field of view and the optical axis relative to the celestial north pole. ang :
[0040] Left boundary of right ascension of the field of view LeftRa and right boundary RighRat for:
[0041] The star set S1 within the right ascension range of the optical axis was selected based on the left and right boundaries. The selection criteria were: the left boundary of the right ascension of the field of view. LeftRa ≤right ascension of stars ra s ≤Right boundary of the right ascension of the field of view RighRat .
[0042] Step 3.3: Select the subset S2 of stars within the declination span of the star sensor's optical axis from the star set S1. The specific steps are as follows: Upper boundary of field of view declination TopDec and lower boundary DownDec for:
[0043] The star set S2 within the optical axis declination range was selected based on the upper and lower boundaries. The selection criteria were: lower boundary of field of view declination. DownDec ≤stellar declination dec s ≤ Upper boundary of field of view declination TopDec .
[0044] The star set S2 is theoretically the set of stars that can enter the outer circle of the star sensor's field of view.
[0045] Step 3.4: Calculate the starlight vector for each star system within star set S2. Vs The specific steps are as follows: Based on the right ascension of each star in star set S2 ra s Declination dec s Calculate the starlight vector in the inertial frame. Vi :
[0046] Transformed to a star-sensitive system, the starlight vector is obtained. Vs :
[0047] Step 3.5: Calculate the coordinates of the star points, select the star points mapped onto the imaging array, and generate the observable star set S. v The specific steps are as follows: Based on the star sensor focal length design value f Focal plane detector pixel size PixSize Calculate the mapped coordinates of stars within the field of view. x , y :
[0048] in, x 0、 y 0 represents the principal point of the imaging array, which is typically set to an ideal value during the design phase.
[0049] in, pixelsX , pixelsY The number of pixels in the focal plane array of the detector represents the size of the imaging array.
[0050] Select the star points mapped onto the imaging array to generate an observable star set S. v The filtering criteria are:
[0051] Step 4: Set the time, location, and attitude sequence for satellite observation, perform continuous satellite observation simulation, and record the observable star set S. v The number of stars in the system. For the same satellite measurement time, a random satellite measurement location can be set, that is, the latitude and longitude are randomly selected globally. The heading angle, pitch angle, and roll angle of the carrier are all set to 0°, and the star-sensor system coincides with the carrier system. , All are unit arrays, thus achieving random pointing of the optical axis of the star sensor across the entire celestial sphere. Extensive Monte Carlo star measurement simulation experiments were conducted, recording the observable star set S. v The number of stars in the system can be recorded. On the other hand, the flight trajectory of the carrier can be programmed according to the application scenario, and the corresponding satellite measurement time, location and attitude sequence can be set to conduct continuous satellite measurement simulation and record the number of stars.
[0052] Step 5: Analyze the satellite detection probability and distribution to assess the availability of design parameters. The specific steps are as follows: Step 5.1: Based on the number of stars and the number of simulations recorded in the continuous star measurement simulation, calculate the star measurement probability, count the observable situation of stars with different brightness, obtain the number of stars that the star sensor can observe and the weakest magnitude under the corresponding design parameters, and evaluate the theoretical star measurement capability corresponding to the design parameters.
[0053] Step 5.2: During each satellite measurement simulation, according to the measurement equations of the integrated navigation system:
[0054] By combining the azimuth and elevation angle information of each observable star, the measurement matrix is calculated. H Thus, the error covariance matrix is calculated. Q :
[0055] Where, q ij For the first i Star measurement and the first j Covariance of star measurements.
[0056] Reference satellite navigation accuracy attenuation factor DOP Definition, calculation accuracy attenuation factor DOP :
[0057] DOP The smaller the value, the more uniform the geometric distribution of stars, and the smaller the astronomical positioning error measured by star information.
[0058] Recording continuous satellite measurement simulation DOP The values are statistically analyzed to determine their magnitude and variation, and the distribution of stars observable by the star sensor under the corresponding design parameters is evaluated.
[0059] Step 5.3: Analyze the star detection probability and distribution of the star sensor under the corresponding design parameters, evaluate the usability of the design parameters, and use them as a reference for iterative design.
[0060] Example 1 In the design process of a certain type of short-wave infrared star sensor, the initial design of the star sensor was 2048×2048 pixels, with a pixel size of 15μm, a focal length of 586mm, and a field of view of [missing information]. ×3 Limiting magnitude +0.5 Mv, optical axis angle with base is 50° The star sensor requires a probability of observing at least two stars in one revolution around the base normal of at least 90%. Continuous star measurement simulations using the method described herein show a probability of observing one or more stars of 99.44% and a probability of observing two or more stars of 95.92%, with a root mean square accuracy attenuation factor (DOP) of 1.61. Analysis indicates that the star measurement capability basically meets the requirements, and the star distribution is good. The initial parameters are basically usable, and detailed design and optimization can be carried out based on this.
[0061] Example 2 In the design process of a certain type of visible light star sensor, the initial design of the star sensor was as follows: 1024×1024 pixels, 15μm pixel size, 58.3mm focal length, and 15... ×15 The limiting magnitude is +5 Mv. This star sensor requires a probability of observing three or more stars at least 99% throughout the entire time period. Continuous star measurement simulations using the method described herein show a probability of observing three or more stars of 96.1%. Analysis indicates that the initial parameters do not meet the requirements, necessitating a redesign.
[0062] It should be noted that the above process operations can be combined to varying degrees. For the sake of simplicity, the implementation methods of various combinations will not be elaborated further. Those skilled in the art can flexibly adjust or combine the order of the steps of the above method (or the position of the product components) according to the actual situation.
[0063] It should be noted that the functional components shown in the above embodiments can be implemented in hardware, software, or a combination of both. When implemented in hardware, they can be electronic circuits, application-specific integrated circuits (ASICs), plug-ins, function cards, etc. When implemented in software, they can be programs or code segments used to perform the required tasks. Programs or code segments can be stored in a machine-readable medium, or they can be transmitted over a transmission medium or communication link via data signals carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet or intranets.
[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be covered within the protection scope of the present invention.
Claims
1. A method for evaluating the probability of star detection using a star sensor, characterized in that, Includes the following steps: Step 1: Generate a selection library of stars based on the star sensor's limiting magnitude design value; Step 2: Set the star measurement time, location, and attitude, and calculate the optical axis pointing of the star sensor; Step 3: Based on the star sensor design parameters and optical axis orientation, further filter the observable star set S from the star library S. v The design parameters of the star sensor include limiting magnitude, field of view, focal length, and focal plane detector pixel size. Step 4: Set the time, location, and attitude sequence for satellite observation, perform continuous satellite observation simulation, and record the observable star set S. v The number of stars in the middle; Step 5: Statistically analyze the satellite detection probability and distribution to assess the availability of design parameters.
2. The method for evaluating the probability of star detection using a star sensor according to claim 1, characterized in that, In step 1, the specific steps are as follows: Step 1.1: Based on the photoelectric characteristics of the star sensor focal plane detector, select a visible light star catalog or an infrared star catalog as the original star catalog; Step 1.2: Select stars in the original star catalog whose magnitude is no greater than the design value of the limit magnitude, store their star number, magnitude, right ascension, declination, proper motion, and spectral type information, and generate the selected star library S.
3. The method for evaluating the probability of star detection using a star sensor according to claim 1, characterized in that, In step 1 and in step 2, the specific steps are as follows: Step 2.1: Based on the stellar observation time, convert Beijing time to Coordinated Universal Time (UTC), Earth Time, UTC, and Julian Day in sequence, calculate the Earth's rotation angle (ERA), and combine this with precession and nutation to obtain the Greenwich Mean Time (GAST) stellar perspective, thereby obtaining the coordinate transformation matrix from the inertial frame to the Earth frame. : ； Step 2.2: Calculate the coordinate transformation matrix from the Earth system to the geographic system based on the carrier's location (Lon and Lat) at the time of satellite measurement. : ； Step 2.3: Based on the heading angle of the carrier relative to the geographic system at the time of satellite measurement. Pitch angle Roll angle Using a 3-1-2 Euler angle transformation, calculate the coordinate transformation matrix from the geographic system to the carrier system. : ； Step 2.4: Based on the installation relationship between the star sensor and the carrier, obtain the coordinate transformation matrix from the carrier system to the star sensor system. ; Step 2.5: Calculate the orientation of the star sensor's optical axis in the inertial frame through coordinate transformation. : ； Step 2.6: Calculate the right ascension corresponding to the direction of the star sensor's optical axis. ra Declination dec : 。 4. The method for evaluating the probability of star detection using a star sensor according to claim 1, characterized in that, In step 1 and step 3, the specific steps are as follows: Step 3.1: Based on the star sensor's field of view size Fov Calculate the equivalent circumcircle diameter of the field of view. D : ； Step 3.2: Select the set of stars S1 within the right ascension range of the star sensor's optical axis from S. The specific steps are as follows: Calculate the zenith angle of the optical axis z : Calculate the spherical angles of the tangent meridian of the circumcircle of the field of view and the optical axis relative to the celestial north pole. ang : Left boundary of right ascension of the field of view LeftRa and right boundary RighRat for: The star set S1 within the right ascension range of the optical axis was selected based on the left and right boundaries. The selection criteria were: the left boundary of the right ascension of the field of view. LeftRa ≤right ascension of stars ra s ≤Right boundary of the right ascension of the field of view RighRat ; Step 3.3: Select the subset S2 of stars within the declination span of the star sensor's optical axis from the star set S1. The specific steps are as follows: Upper boundary of field of view declination TopDec and lower boundary DownDec for: The star set S2 within the optical axis declination range was selected based on the upper and lower boundaries. The selection criteria were: lower boundary of field of view declination. DownDec ≤stellar declination dec s ≤ Upper boundary of field of view declination TopDec ; Then star set S2 is the set of stars that can theoretically enter the outer circle of the star sensor's field of view; Step 3.4: Calculate the starlight vector for each star system within star set S2. Vs The specific steps are as follows: Based on the right ascension of each star in star set S2 ra s Declination dec s Calculate the starlight vector in the inertial frame. Vi : Transformed to a star-sensitive system, the starlight vector is obtained. Vs : ； Step 3.5: Calculate the coordinates of the star points, select the star points mapped onto the imaging array, and generate the observable star set S. v The specific steps are as follows: Based on the star sensor focal length design value f Focal plane detector pixel size PixSize Calculate the mapped coordinates of stars within the field of view. x , y : in, x 0、 y 0 is the principal point of the imaging array, which is set as an ideal value during the design phase. in, pixelsX , pixelY The number of pixels in the focal plane array of the detector represents the size of the imaging array. Select the star points mapped onto the imaging array to generate an observable star set S. v The filtering criteria are: 。 5. The method for evaluating the probability of star detection using a star sensor according to claim 1, characterized in that, In step 1 and step 4, for the same satellite measurement time, a random satellite measurement location can be set, i.e., latitude and longitude values can be randomly selected globally. The carrier's heading angle, pitch angle, and roll angle are all set to 0°, and the star-sensor system coincides with the carrier system. , All are unit arrays, thus achieving random pointing of the optical axis of the star sensor across the entire celestial sphere. Extensive Monte Carlo star measurement simulation experiments were conducted, recording the observable star set S. v On the one hand, it can count the number of stars in the satellite; on the other hand, it can also compile the flight trajectory of the carrier according to the application scenario, set the corresponding satellite measurement time, location and attitude sequence, conduct continuous satellite measurement simulation, and record the number of stars.
6. The method for evaluating the probability of star detection using a star sensor according to claim 1, characterized in that, In step 1 and step 5, the specific steps are as follows: Step 5.1: Based on the number of stars and the number of simulations recorded in the continuous star measurement simulation, calculate the star measurement probability, count the observable situation of stars with different brightness, obtain the number of stars that the star sensor can observe and the weakest magnitude under the corresponding design parameters, and evaluate the theoretical star measurement capability corresponding to the design parameters. Step 5.2: In each satellite measurement simulation process, according to the measurement equations of the integrated navigation system: By combining the azimuth and elevation angle information of each observable star, the measurement matrix is calculated. H Thus, the error covariance matrix is calculated. Q : Where, q ij For the first i Star measurement and the first j Covariance of star measurements; Reference satellite navigation accuracy attenuation factor DOP Definition, calculation accuracy attenuation factor DOP : DOP The smaller the value, the more uniform the geometric distribution of stars, and the smaller the astronomical positioning error measured by star information; Recording continuous satellite measurement simulation DOP The values are statistically analyzed to determine their magnitude and variation, and the distribution of stars observable by the star sensor under the corresponding design parameters is evaluated. Step 5.3: Analyze the star detection probability and distribution of the star sensor under the corresponding design parameters, evaluate the usability of the design parameters, and use them as a reference for iterative design.
7. A computer-readable storage medium, characterized in that, Includes computer program instructions, which, when executed by a computing device or processor, perform the method as described in any one of claims 1-6.
8. A computer program product containing instructions, characterized in that, When the instructions are executed by a computing device or processor, the computing device or processor performs the method as described in any one of claims 1-6.