Optical satellite data processing method

Abstract

The application provides an optical satellite data processing method, relates to the technical field of satellite data processing, and can solve the problem of slow remote sensing satellite data extraction. The method comprises the following steps: determining slice start and end times of an observation task; extracting original code stream data according to the slice start and end times to obtain first CCD formatted data covering a target area; in the case that the target area is less than or equal to a preset threshold, slicing the first CCD formatted data to obtain slice data; in the case that the target area is greater than the preset threshold, splicing the first CCD formatted data to obtain spliced data; and producing standard products from the slice data or the spliced data; wherein the observation task comprises an emergency observation task, and the first CCD formatted data comprises formatted data of at least one CCD. According to the method, image data of an emergency point target or an emergency area can be processed and distributed according to slices or scenes, and the data processing efficiency of the emergency observation task is improved.

Description

Technical Field

[0001] This invention relates to the field of satellite data processing technology, and in particular to an optical satellite data processing method. Background Technology

[0002] Remote sensing satellites carry various payloads, including panchromatic-multispectral cameras, hyperspectral cameras, and satellite cameras. The focal planes of these cameras are, for example, composed of multiple charge-coupled devices (CCDs) stitched together. During payload observations, each CCD independently acquires grayscale images of ground features and encodes and stores them in onboard solid-state storage (SSD). Because remote sensing satellites carry a large number of payloads, the total data acquisition rate of all payloads exceeds the maximum recording rate of a single satellite SSD during full mission operation. Therefore, remote sensing satellites are equipped with multiple onboard SSDs to store data from different payloads and different CCDs in different SSDs, ensuring a balance of data volume across all SSDs.

[0003] When the satellite passes through the visible arc of the ground receiving station, the satellite data transmission system reads the same payload data from different storage devices at the same rate and transmits it to the ground. If the ground data processing system detects that the data from all CCDs on the payload are complete, it stitches together a complete high-resolution optical image based on information such as the geometric relationship of the CCD installation positions, the overlapping pixels of adjacent CCDs, and the attitude and position at the time of observation.

[0004] However, in actual operation, due to the different mission modes and the different ground object data acquired by each payload and each CCD, the amount of data stored in the fixed storage after compression and encoding is also different. However, the satellite data transmission system reads the payload data from each fixed storage at the same rate for playback, resulting in a difference of tens of GB in the daily storage capacity between the fixed storage of remote sensing satellites. The time for the data of each CCD of the payload to be fully assembled can even reach 24 to 48 hours, which affects the rapid application of remote sensing satellite data. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the existing technical problems, this invention provides an optical satellite data processing method that at least partially solves the above-mentioned technical problems.

[0007] (II) Technical Solution

[0008] This invention provides an optical satellite data processing method, comprising: determining the start and end times of a slice for an observation mission; extracting raw bitstream data based on the slice start and end times to obtain first CCD formatted data covering a target area; slicing the first CCD formatted data to obtain sliced ​​data when the target area is less than or equal to a preset threshold; stitching the first CCD formatted data together when the target area is greater than the preset threshold to obtain stitched data; and producing a standard product from the sliced ​​data or stitched data; wherein the observation mission includes an emergency observation mission, and the first CCD formatted data includes formatted data from at least one CCD.

[0009] Optionally, determining the start and end times of the slices for the observation task includes: determining the start and end times of the payload observations for the observation task; determining the start and end times of the observations for each CCD based on the payload observation start and end times; determining the first observation time of the payload for the center point of the target area; determining the second observation time of each CCD for the center point of the target area based on the payload observation start and end times, the observation start and end times of each CCD, and the first observation time; determining the positions of the four corner points of the slices in the target area and the slice length along the track direction; and determining the start and end times of the slices based on the second observation time, the positions of the four corner points of the slices, and the slice length along the track direction.

[0010] Optionally, extracting the original bitstream data based on the slice start and end times to obtain the first CCD formatted data covering the target area includes: extracting the initial formatted data of each CCD from the first data receiving task based on the observation start and end times of each CCD, and recording the actual observation start and end times of the observation task; recording the first correspondence between the initial formatted data of each CCD and the original bitstream data; and based on the first correspondence, deduplicating and splicing the initial formatted data of each CCD by frame count to obtain the first CCD formatted data, and updating the actual observation start and end times of the observation task.

[0011] Optionally, if the target area is less than or equal to a preset threshold, the first CCD formatted data is sliced ​​to obtain sliced ​​data, which includes: determining the relationship between the acquisition start and end time of the first CCD formatted data and the updated actual observation start and end time; if the acquisition start and end time is included in the actual observation start and end time, extracting auxiliary data of the first CCD formatted data according to the acquisition start and end time; determining the four corner point information of the first CCD formatted data based on the auxiliary data; determining the initial sliced ​​data based on the four corner point information of the first CCD formatted data; and if the initial sliced ​​data intersects with the target area, performing radiometric correction and geometric positioning processing on the initial sliced ​​data to obtain sliced ​​data.

[0012] Optionally, if the target area is larger than a preset threshold, the first CCD formatted data is stitched together to obtain stitched data, which includes: determining the coverage area of ​​the first CCD formatted data; stitching the first CCD formatted data according to the location based on the coverage area to obtain stitched data; wherein the stitched data is greater than or equal to one scene data.

[0013] Optionally, the slice data includes CCD slice data and / or stitched CCD slice data. Standard product production from the slice data or stitched data includes: standard product production from the CCD slice data; and / or stitching adjacent CCD slice data to obtain initial stitched CCD slice data; cropping the initial stitched CCD slice data according to the target area to obtain stitched CCD slice data; and standard product production from the stitched CCD slice data.

[0014] Optionally, standard product production for sliced ​​or stitched data includes: producing standard products for stitched data scene by scene; or determining a preset number of data receiving tasks; and producing standard products for stitched data when the number of second data receiving tasks reaches the preset number of data receiving tasks.

[0015] Optionally, after producing a standard product from the stitched data, the optical satellite data processing method further includes: reacquiring second CCD formatted data related to the observation mission; recording a second correspondence between the second CCD formatted data and the original bitstream data; and producing a standard product from the second CCD formatted data.

[0016] Optionally, the optical satellite data processing method further includes: replaying historical raw bitstream data according to a first correspondence and / or a second correspondence to obtain third CCD formatted data covering the target area; producing standard products from the third CCD formatted data according to the observation task; wherein the priority of the task of replaying historical raw bitstream data is lower than the priority of the real-time data receiving task.

[0017] Optionally, replaying historical raw bitstream data to obtain third CCD formatted data covering the target area includes: replaying the historical raw bitstream data according to the order in which the observation task is actually included in the historical raw bitstream data; or determining the third data receiving task corresponding to each CCD of the observation task, and replaying the historical raw bitstream data according to the receiving order of the third data receiving task; producing standard products from the third CCD formatted data according to the observation task includes: determining the fourth CCD formatted data of one or more payloads corresponding to the observation task; and producing standard products from the fourth CCD formatted data.

[0018] (III) Beneficial Effects

[0019] Compared with the prior art, the optical satellite data processing method provided by the present invention has at least the following beneficial effects:

[0020] (1) The optical satellite data processing method of the present invention, for emergency point target (small area) observation tasks, as long as a certain CCD covers the point target slice area, can initiate slice rapid radiation and geometric positioning tasks to ensure that emergency slice data can be quickly distributed to users; for emergency area (large area) observation tasks, as long as each CCD meets the production requirements of a scene product, can stitch together CCD formatted data and initiate subsequent standard product production and distribution tasks according to scene to ensure that emergency area data is quickly distributed to users and improve the data processing efficiency of emergency observation tasks.

[0021] (2) The optical satellite data processing method of the present invention, for the regeneration of unbalanced data, records the correspondence between each CCD actually contained in the original code stream data and the observation task and data receiving task. When replaying the original code stream data, the correspondence is used to replay only the original code stream data of the specified task, and only initiate the specified observation task or the specified payload regeneration task, thus saving a lot of computing and storage resources. Attached Figure Description

[0022] The above and other objects, features and advantages of the present invention will become more apparent from the following description of embodiments of the invention with reference to the accompanying drawings, in which:

[0023] Figure 1 A flowchart illustrating an optical satellite data processing method according to an embodiment of the present invention is shown schematically.

[0024] Figure 2 An optical image illustrating the observation of an emergency point target according to an embodiment of the present invention is shown schematically;

[0025] Figure 3 An optical image of an emergency area observed according to an embodiment of the present invention is shown schematically. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0027] It should be noted that similar or identical parts are referred to by the same reference numerals in the accompanying drawings or description. The technical features of the various embodiments exemplified in the specification can be freely combined to form new solutions without conflict, and the shape or thickness of the embodiments may be enlarged in the drawings and indicated in a simplified or convenient manner. Furthermore, elements or implementations not shown or described in the drawings are in forms known to those skilled in the art. Additionally, while this document provides examples of parameters containing specific values, it should be understood that the parameters need not be exactly equal to the corresponding values, but can approximate the corresponding values ​​within acceptable error tolerances or design constraints.

[0028] Unless there are technical obstacles or contradictions, the various embodiments of the present invention described above can be freely combined to form other embodiments, all of which are within the protection scope of the present invention.

[0029] Although the invention has been described in conjunction with the accompanying drawings, the embodiments disclosed in the drawings are intended to illustrate preferred embodiments of the invention and should not be construed as limiting the invention. The dimensions and proportions in the drawings are merely illustrative and should not be construed as limiting the invention.

[0030] While some embodiments of the general concept of the present invention have been shown and described, those skilled in the art will understand that changes may be made to these embodiments without departing from the principles and spirit of the general concept disclosed herein.

[0031] Research indicates that remote sensing satellite observation missions are categorized into emergency observation missions and routine observation missions based on user needs. Emergency observation missions target sudden events such as volcanoes, earthquakes, mudslides, and floods, requiring rapid acquisition and distribution of target images to users. Routine observation missions acquire basic ground feature information and have less stringent timeliness requirements. Addressing the issue of unbalanced data storage in remote sensing satellites, relevant technical solutions require the ground data processing system to have complete sets of CCD data from all payload slices for both emergency and routine observation missions before initiating subsequent cataloging, standard product production, and distribution tasks. The distribution delay for emergency products can reach 24 hours, severely hindering the application of remote sensing satellite data products.

[0032] In view of the above problems, this invention proposes an optical satellite data processing method. This method analyzes the formatted data of each CCD chip in the received payload, adopts a strategy of producing data as much as is received, and performs emergency production tasks on a chip-by-chip basis, thus solving the problem of long waiting times for payload data to be complete.

[0033] Figure 1 A flowchart illustrating an optical satellite data processing method according to an embodiment of the present invention is shown.

[0034] According to embodiments of the present invention, such as Figure 1 As shown, optical satellite data processing methods include, for example:

[0035] S110, determine the start and end times of the slice for the observation task.

[0036] S120: Based on the start and end times of the slice, extract the original bitstream data to obtain the first CCD formatted data covering the target area.

[0037] S130, if the target area is less than or equal to a preset threshold, slice the formatted data of the first CCD to obtain sliced ​​data.

[0038] S140, if the target area is larger than a preset threshold, the formatted data of the first CCD is spliced ​​to obtain spliced ​​data.

[0039] S150 is used to produce standard products from sliced ​​or stitched data. The observation tasks include emergency observation tasks, and the first CCD formatted data includes formatted data from at least one CCD.

[0040] For example, processing data from optical satellites, which includes observation mission data from different time periods. First, the start and end times of the observation mission slices are determined, for example, from 23:59:57.5 on March 1, 2023, to 23:59:59 on March 1, 2023. Then, based on this slice start and end time, first CCD formatted data covering the target area is extracted from the raw bitstream data. Next, the size of the target area is checked. If the target area is less than or equal to a preset threshold (e.g., 100 square kilometers), the first CCD formatted data is sliced ​​to obtain sliced ​​data. These sliced ​​data can include time-series data for each pixel, such as an image taken every 5 seconds. If the target area is larger than the preset threshold, the first CCD formatted data is stitched together to obtain stitched data. These stitched data can include formatted data from multiple CCDs; for example, data from two different CCDs is merged into a larger image. Finally, standard products are produced from the sliced ​​or stitched data. This can include further processing, analysis, and interpretation of the data to generate useful information or decision support tools. For example, sliced ​​or stitched data can be converted into Geographic Information System (GIS) format, or machine learning algorithms can be used to identify and classify different objects or phenomena in a target area.

[0041] Among these, observation tasks can be emergency observation tasks, meaning that data needs to be acquired and processed quickly to respond promptly to emergencies. For example, in the event of a natural disaster such as an earthquake or flood, the observation task can be set as an emergency observation task, and the aforementioned data processing methods can be used to acquire and analyze real-time data from the affected area. In this case, the first CCD formatted data can include formatted data from at least one CCD to meet the need for rapid response.

[0042] According to an embodiment of the present invention, determining the start and end times of a slice for an observation task includes, for example:

[0043] S211, determine the start and end times of the payload observation for the observation mission.

[0044] S212, determine the observation start and end times for each CCD based on the load observation start and end times.

[0045] S213, determine the first observation time of the target area center point by the payload of the observation mission.

[0046] S214. Based on the start and end times of the load observation, the start and end times of the observation for each CCD, and the first observation time, determine the second observation time for each CCD of the target area center point.

[0047] S215 determines the positions of the four corner points of the slice in the target area and the slice length along the track direction. And...

[0048] S216. Determine the start and end times of the slice based on the second observation time, the positions of the four corner points of the slice, and the slice length along the track direction.

[0049] For example, optical payload CCDs are typically assembled using optical or mechanical stitching to form a large field-of-view camera focal plane. Mechanical stitching involves staggering the CCDs in a triangular pattern. Optical stitching requires them to be approximately aligned in a straight line, but installation errors exist, making it impossible to guarantee perfect alignment. Therefore, during payload observations, the ground features acquired in the overlapping area of ​​two adjacent CCDs at the same time may differ, with the acquisition time difference for the same ground features in the overlapping area reaching more than one second.

[0050] Therefore, the ground control system uses a specific CCD on the payload as a reference to generate the start and end times of the entire payload observation mission. After receiving the observation mission, the data processing system needs to calculate the observation time of each CCD on the payload and the overpass time of the emergency target center point based on the observation start and end response delay between each CCD on the payload and the reference CCD. The main processing steps include, for example:

[0051] R11, ObsPlan for Observation Tasks j Load observation start and end time T js and T jeThe observation start and end time T of the i-th CCD is calculated according to formulas (1) and (2). ijs and T ije .

[0052] T ijs =T js +ΔT is (1)

[0053] T ije =T je +ΔT ie (2)

[0054] Among them, ObsPlan j This represents the j-th observation task, where i is the CCD slice number (1 ≤ i ≤ N), N is the number of CCD slices in the payload, and ΔT is The delay ΔT is the start of the response from the i-th CCD observation. ie It is the response delay after the observation of the i-th CCD.

[0055] In some embodiments, the response delay time ΔT between each CCD and the reference CCD is and ΔT ie When the payload's operating modes differ, the values ​​also differ. This requires calibration by analyzing the time differences between observations of adjacent CCD objects with the same name in different payload operating modes obtained earlier, and storing this data in the data processing system as a configuration file. Simultaneously, for the j-th observation task of the payload, the operation and control system, based on the predicted orbit data and using the CCD image at the payload's midpoint as a reference, extrapolates and generates the start and end times T of the observation area covered by the payload's observation task. js and T je After receiving the observation task, the data processing system retrieves the response delay ΔT between each CCD of the corresponding payload and the reference CCD from the configuration file. is and ΔT ie Then, the start and end times T of the j-th observation task for each CCD are calculated according to formulas (1) and (2). ijs and T ije .

[0056] R12, ObsPlan for Observation Tasks j Load m-th emergency point target center point P m Observation time T jmo And according to formula (3), the observation time T of each CCD observing the center point of the target is calculated. ijmo 1≤m≤M, where M is the observation task ObsPlan j Number of emergency target points covered.

[0057] T ijmo =T ijs +Tjmo -T js (3)

[0058] Among them, T ijs T is the start time of observation for the i-th CCD. js The start time of the load observation.

[0059] Figure 2 An optical image illustrating the observation of an emergency point target according to an embodiment of the present invention is shown schematically.

[0060] In some embodiments, such as Figure 2 As shown, the planned emergency point center point P for the j-th observation mission is... m The observation time is generated by the operation and control system based on satellite predicted orbit data and transmitted to the data processing system through the observation mission. The data processing system receives the observation time information for the emergency target point of the observation mission and calculates the time of passage through the target's center point P. m The reference CCD at time T is observed continuously for a period of time. jmo -T js And based on the load, the observation start time T of each CCD is determined. ijs Calculate the corresponding CCD passing through the emergency target center point P. m The observation time.

[0061] It should be noted that the "emergency point target" referred to in this invention is a relatively small area corresponding to the emergency observation task, such as an area of ​​100 square kilometers.

[0062] R13. Obtain the positions of the four corner points and the slice length L along the track direction of the observation task slice data, and calculate the start and end time T of each CCD coverage slice according to formula (4) and formula (5). ijms and T ijme .

[0063] T ijms =T ijmo -L / 2V-ΔT r (4)

[0064] T ijme =T ijmo +L / 2V+ΔT r (5)

[0065] Where, ΔT r It is the coverage slice error time, which is usually taken as 0.5 seconds, and V is the satellite ground velocity, which is usually taken as 7.2 km / s.

[0066] In some embodiments, the emergency target P of the j-th observation task moiThe locations of the four corner points of the emergency slice data can be transmitted to the data processing system through the observation task information, and the data processing system can use them directly.

[0067] In some embodiments, the observation task information only includes the location information of the emergency point target. The data processing system uses the location of the emergency point target as a reference and, based on the payload swath width, recalculates the latitude and longitude information of the four corner points of the upper left, lower left, upper right, and lower right of the slice using a configurable slice size. Commonly used slice sizes include 2km×2km, 5km×5km, 10km×10km, or 20km×20km, which are much smaller than the payload swath width. When the length of the slice along the track direction is L, the time for the payload to acquire image data of the slice area is L / V. Then, the center point P of the emergency point target covered by the i-th CCD can be calculated according to formulas (4) and (5). m Slicing start and end times T ijms and T ijme .

[0068] R14. If the observation mission covers M emergency observation target points, repeat steps R12 to R13 to obtain the observation start and end times and the center point overpass time for each CCD of the observation mission payload covering each emergency target.

[0069] In some embodiments, a remote sensing satellite can continuously observe for tens of minutes at a time, covering hundreds of thousands of square kilometers of terrain and including multiple emergency point targets. In this case, steps R12 to R13 are repeated to estimate the start and end times of observation for each CCD of the payload covering the emergency point targets and the overpass time of the center point of the emergency point targets, based on the overpass time of each emergency point target in the observation mission.

[0070] According to an embodiment of the present invention, the original bitstream data is extracted based on the start and end times of the slice to obtain first CCD formatted data covering the target area, for example including:

[0071] S321, based on the observation start and end time of each CCD, extract the initial formatted data of each CCD from the first data receiving task, and record the actual observation start and end time of the observation task.

[0072] S322 records the initial correspondence between the formatted data of each CCD and the original bitstream data.

[0073] S323, according to the first correspondence, the formatted data of each initial CCD is deduplicated and spliced ​​according to the frame count to obtain the first CCD formatted data, and the actual observation start and end time of the observation task is updated.

[0074] For example, raw data streams are binary files generated from the high-frequency downlink data transmission signals received by the ground station from the satellite after frequency conversion and demodulation. These files can contain raw observation data from multiple observation tasks. However, the raw observation data needs to undergo frame synchronization, descrambling, LDPC correction, decryption, channel merging, virtual channel separation, decompression, and formatting before it can be restored. Furthermore, it needs to be segmented according to the observation tasks. The main processing steps include, for example:

[0075] R21, based on the observation task ObsPlan j The start and end times of the observation of the i-th CCD are extracted from the formatted data of the i-th CCD in the data receiving task, thus determining the ObsPlan of the observation task. i The i-th CCD image is formatted, and the actual observation start and end times T are recorded. ijas and T ijae .

[0076] In some embodiments, the line time T for parsing the formatted data of the i-th CCD chip line by line is... L When T ijs ≤T L ≤T ije This indicates that row L belongs to the OB Plan of the i-th CCD. j Data from the observation mission. At this point, create temporary files named according to satellite name, CCD serial number, observation mission plan number, and data reception mission tracking and reception plan number, storing the data for the i-th CCD in ascending order of line time and line count. j Observation mission data.

[0077] Among them, T ijas =min(T) L ), T ijae =max(T) L A temporary file naming format is, for example: Satellite Name_CCD-i_Observation Mission Plan Number_Data Reception Mission Tracking Reception Plan Number.FRED.

[0078] In some embodiments, when the data of the i-th CCD is stored in different storage locations according to the left and right fields of view, the formatted data of the left and right fields of view of the i-th CCD are stored separately and the left and right fields of view are identified.

[0079] R22, Record Observation Task ObsPlan j The actual correspondence between the formatted data of the i-th CCD and the original bitstream data of the data receiving task.

[0080] In some embodiments, the observation task ObsPlan j The correspondence between the formatted data of the i-th CCD chip and the raw bitstream data of the data receiving task includes, for example, the CCD chip number and the observation task ObsPlan.j The plan number and data receiving task tracking plan number are recorded in the observation task and data receiving task relationship table to associate the relationship between observation tasks and data receiving tasks.

[0081] It should be noted that since a data receiving task can include multiple observation tasks, and an observation task can be transmitted through multiple data receiving tasks, this correspondence is a many-to-many relationship.

[0082] R23. When a previously completed data reception task includes an observation task ObsPlan j For the i-th CCD data, deduplication and splicing are performed according to the i-th CCD formatted data frame count, and temporary files before splicing are cleaned up.

[0083] In some embodiments, when the observation task ObsPlan j The formatted data of the i-th CCD corresponds to multiple data receiving task tracking receiving plan numbers in the observation task and data receiving task relationship table, and the temporary file generated in step R21 still exists. Therefore, for the observation task ObsPlan... j The temporary file containing the formatted data from the i-th CCD is deduplicated and stitched together according to the increasing order of row time and row count to generate a complete observation task ObsPlan. j The i-th CCD formatted data is then updated, along with the actual observation start and end times T after stitching. ijas and T ijae At the same time, it cleans up temporary files generated in step R21 according to lifecycle or storage capacity.

[0084] According to an embodiment of the present invention, when the target area is less than or equal to a preset threshold, the formatted data of the first CCD is sliced ​​to obtain sliced ​​data, for example including:

[0085] S431, determine the relationship between the start and end times of acquiring the first CCD formatted data and the updated start and end times of the actual observation.

[0086] S432, if the acquisition start and end times are included in the actual observation start and end times, extract auxiliary data of the first CCD formatted data according to the acquisition start and end times.

[0087] S433, Based on the auxiliary data, determine the four corner point information of the first CCD formatted data.

[0088] S434, based on the corner point information of the first CCD formatted data, determines the initial slice data.

[0089] S435, when there is an intersection between the initial slice data and the target area, the initial slice data is subjected to radiometric correction and geometric positioning processing to obtain the slice data.

[0090] For example, by using multiple CCDs stitched together, an optical payload can acquire image data with a swath width of tens to thousands of kilometers. However, for emergency point targets, users only need image information covering a radius of a few kilometers centered on their point, which can be covered by a few CCDs. Therefore, for emergency point targets, it is not necessary to wait for all CCDs to be assembled before initiating subsequent tasks; instead, emergency target production tasks need to be initiated piece by piece based on the coverage of each CCD. The main processing steps include, for example:

[0091] R31, When the observation task ObsPlan j Includes emergency point target P moi If the acquisition time of the start and end times of the observation of the i-th CCD satisfies T ijas <T ijrs <T ijre <T ijae Then extract [T] by time. ijrs T ijre The i-th CCD formatted data and auxiliary data are processed, and the corresponding coverage corner point information P is calculated. imoi .

[0092] In some embodiments, time information is first used to determine whether the CCD covers the target point slice. When the acquired observation task ObsPlan... j The actual observation start and end time T of the i-th CCD formatted data ijas and T ijae Includes the j-th CCD covering the emergency target P moi Start and end acquisition time T ijrs and T ijre This indicates that, in the time dimension, the i-th CCD observes the emergency target P. moi The raw observation data has been transmitted to the data processing system. Extracting [T] by time information. ijrs T ijre The i-th CCD formatted data and auxiliary data slices are used, and the attitude information, orbit information and travel time information contained in the auxiliary data slices are used to quickly calculate the latitude and longitude information P of the four corner points corresponding to the slice (top left, bottom left, top right and bottom right). imoi .

[0093] R32, when For [T] ijrs T ijreThe i-th CCD formatted data between [ ] is processed by rapid radiometric correction and geometric positioning to obtain a clear image of the target and its location information.

[0094] In some embodiments, when This indicates that the i-th CCD is in [T] ijrs T ijre Formatted data slices within a time period are not only related to the emergency target P in terms of time. moi There is an intersection, both spatially and spatially. At this point, it can be confirmed that the i-th CCD formatted data slice covers the emergency target P. moi Therefore, for [T] ijrs T ijre The i-th CCD formatted data slice between [ ] is subjected to rapid radiometric correction and geometric positioning processing.

[0095] R33. Repeat steps R31 to R32 to obtain the observation task ObsPlan. j All covered emergency point targets P moi The data consists of CCD slices. When there are overlapping areas between these CCD slices, the overlapping CCD slices are stitched together.

[0096] In some embodiments, such as Figure 2 As shown, the optical camera has, for example, nine CCDs, of which CCD3 to CCD7 cover the emergency point target P. moi When step R32 produces slice data of two adjacent CCDs, CCD3 and CCD4, the two slices of CCD3 and CCD4 are stitched together to generate a stitched slice image.

[0097] According to an embodiment of the present invention, when the target area is larger than a preset threshold, the formatted data of the first CCD is spliced ​​together to obtain spliced ​​data, for example including:

[0098] S541, determine the coverage area of ​​the first CCD formatted data.

[0099] S542, based on the coverage area, stitch the formatted data from the first CCD according to the location to obtain stitched data. The stitched data is greater than or equal to one scene's data.

[0100] For example, when the formatted data size of each CCD and the observation duration is basically consistent with the planned observation duration of the observation mission, it indicates that the observation mission's CCDs are complete, and subsequent data processing tasks can be initiated. However, due to memory imbalances, frame drops, and bit errors during satellite-to-ground data transmission, the data from each CCD may not arrive at the data processing system according to the planned time of the operation and control system. For emergency area target observation missions, different data processing strategies are employed, for example, through the following steps:

[0101] R41, When the observation task ObsPlan j It is an emergency area observation, calculating the actual received observation tasks (ObsPlan). j The i-th CCD formatted data coverage area P i And press P on all CCDs i The positions are spliced ​​together. If the spliced ​​P meets at least the data size of one scene, then the subsequent standard product production and distribution tasks are initiated according to the scene.

[0102] Figure 3 An optical image of an emergency area observed according to an embodiment of the present invention is shown schematically.

[0103] In some embodiments, such as Figure 3 As shown, emergency area observation missions require the rapid acquisition of remote sensing image data over large areas and wide regions; therefore, standard image products need to be distributed on a scene-by-scene basis. Step R41: When the observation mission ObsPlan... j This is an emergency area observation mission. For the i-th CCD formatted data processed in step R23, attitude, orbit, and travel time information are extracted from all auxiliary data. The latitude and longitude information P of the four angle points of the entire CCD is then calculated. i And press P on all CCDs i The locations are stitched together to generate the received observation task ObsPlan. j All CCDs are formatted to cover an area P, and P is cropped to ensure that data exists in the overlapping areas of adjacent CCDs, with no missing CCD slices. If P covers the emergency observation area and meets the data size requirement for at least one scene, then standard products are generated for the emergency observation area task data scene by scene, and distributed after generation.

[0104] For example, if the load width is Sample km, then the size of the scene is Sample × Sample.

[0105] According to embodiments of the present invention, the slice data includes, for example, CCD slice data and / or stitched CCD slice data, and the production of standard products from the slice data or stitched data includes, for example, the following:

[0106] S651, for producing standard products from CCD slice data. and / or

[0107] S652, stitches adjacent CCD slice data together to obtain initial stitched CCD slice data.

[0108] S653, based on the target area, the initial stitched CCD slice data is cropped to obtain stitched CCD slice data.

[0109] S654 is used for standard product production from stitched CCD slice data.

[0110] For example, for emergency target locations, it is not necessary to wait for all CCDs to be assembled before initiating subsequent tasks. Instead, emergency target production tasks can be initiated on a per-CCD basis, based on the coverage of each target location by each CCD. The main processing steps also include:

[0111] R34. If there is only one emergency slice after stitching, the emergency slice is then re-stitched according to the emergency point target P. moi Slices are distributed after being sized and trimmed; otherwise, all emergency slices are distributed externally.

[0112] In some embodiments, such as Figure 2 As shown, if step R32 does not generate CCD5-CCD7 slice images, and step R33 only generates one slice image after stitching CCD3 and CCD4, then this slice image is again processed according to the emergency point target P. moi The slices are only distributed after being cropped at the four angles. That is, if there is only one emergency slice after stitching, the emergency slice is then processed again by pressing P. moi After the slices are cropped, they are distributed. If step R32 only generates slice images of CCD3, CCD4, and CCD6, and step R33 generates a slice image after stitching CCD3 and CCD4, then there are two slice images (including a single CCD6). In order to ensure the application needs of emergency observation tasks, they are directly distributed. That is, if there are at least two slice images of a point target, then all slice images are distributed.

[0113] R35. Repeat steps S110 to S150 to complete the production and distribution of slice images of all emergency point targets covered by each payload of the observation task.

[0114] According to embodiments of the present invention, the production of standard products from sliced ​​or stitched data includes, for example:

[0115] S751, standard product manufacturing based on scene-by-scene splicing data. Or

[0116] S752, determine the preset number of data reception tasks.

[0117] S753, when the number of second data receiving tasks reaches the preset number of data receiving tasks, standard product production is performed on the spliced ​​data.

[0118] For example, for emergency area target observation tasks, depending on different data processing strategies, the following steps are also included:

[0119] R42, When the observation task ObsPlan jThe plan is to transmit data to the ground through NUM data receiving tasks. Once the corresponding NUM data receiving tasks are completed, including decryption, channel merging, virtual channel separation, decompression, and formatting, the subsequent cataloging and standard product production tasks will be initiated directly, regardless of whether the CCD data of each observation task ObsPlanj is complete.

[0120] In some embodiments, when the observation mission lasts for a long period, a single data reception mission cannot transmit all the data to the ground system. (Observation mission ObsPlan) j The plan was to transmit data to the ground via NUM data receiving missions. However, due to data imbalance, the actual transmission to the ground system was achieved via NUM-k or NUM+k data receiving missions, i.e., the observation mission ObsPlan. j The transmission may be completed ahead of schedule, or it may require more transmissions. At this point, when NUM data receiving tasks have been completed, regardless of the observation task ObsPlan... j To ensure the completeness of the CCD data set, the system directly initiates subsequent cataloging and standard product production tasks for the received formatted CCD data, guaranteeing the application and processing of this data. Here, k≥1 and NUM-k≥1, meaning the observation task requires at least one transmission.

[0121] According to an embodiment of the present invention, after standard product production of the stitched data, the optical satellite data processing method further includes, for example:

[0122] S810, reacquire the second CCD formatted data related to the observation mission.

[0123] S820 records the second correspondence between the formatted data from the second CCD and the original bitstream data.

[0124] S830 is used for standard product production based on formatted data from the second CCD.

[0125] For example, for emergency area target observation tasks, depending on different data processing strategies, the following steps are also included:

[0126] R43, When the observation task ObsPlan j After receiving data from NUM corresponding data receiving tasks, the observation task ObsPlan is also received in subsequent data receiving tasks. j Several CCD formatted data sets record the correspondence between CCD data and the original bitstream data of the data receiving task, and this is done regardless of the observation task's ObsPlan. j Once the data for each CCD is complete, the subsequent cataloging and standard product production tasks will be initiated.

[0127] In some embodiments, when frame loss or bit errors occur in the data receiving task, the observation task ObsPlan...j If the formatting is discontinuous, the observation mission ObsPlan will be re-transmitted from the satellite. j Data. Furthermore, storage imbalances may affect the obscuration plan. j In reality, the transmission is not received by NUM data receiving tasks alone. Therefore, when the observation task ObsPlan... j After receiving data from NUM corresponding data receiving tasks, the observation task ObsPlan is also received in subsequent data receiving tasks. j For certain CCD formatted data, the correspondence between the CCD data and the raw bitstream data of the data receiving task is recorded in the observation task and data receiving task relationship table, and this is done regardless of the observation task's ObsPlan. j Check if the data for each CCD is complete. For the formatted data of each CCD that has been received, initiate subsequent cataloging and standard product production tasks directly to ensure that this part of the data is applied and processed.

[0128] For example, for a typical observation task, the following steps are performed:

[0129] R44, When the observation task ObsPlan j For routine observation missions, which do not require emergency point target slice production or regional target production, the ObsPlan for the observation mission will be used. j The completion of receiving data for each of the corresponding NUM data receiving tasks is determined until the observation task ObsPlan is completed. j Only after all CCD data is complete can the subsequent cataloging and standard product production tasks be initiated.

[0130] In some embodiments, the timeliness requirements of the observation task are not high, and the computing and storage resources are limited. The subsequent cataloging and standard product production tasks initiated by the observation task rely solely on the completeness information of the data from each CCD, without considering the observation task ObsPlan. j The system checks whether the reception of NUM data receiving tasks is complete until all CCD data is collected before initiating subsequent cataloging and standard product production tasks. Simultaneously, during routine observation tasks, for some previously unreceived data from emergency point and regional target observation tasks, cataloging and standard product production tasks are initiated again after all CCD data is collected, serving as historical data backups. After the cataloging task is completed and all CCD data is collected, the temporary files generated in step S120 are cleaned up according to the temporary data cleanup strategy.

[0131] R45, When the observation task ObsPlan jIf a subsequent cataloging or standard product production task is initiated, and the previously initiated task has not yet been completed, then the task is stopped and the generated data is deleted. If the task has already been completed, then the cataloged formatted data and product data are deleted, retaining only the last cataloged formatted data and product data.

[0132] In some embodiments, since steps R42 and R43 do not take into account the observation task ObsPlan j Whether the CCD data is complete is a key concern. For the formatted data of each received CCD, subsequent cataloging and standard product production tasks are initiated directly. Therefore, data from the same observation task may result in multiple production runs and multiple sets of product data. When the observation task ObsPlan... j If a subsequent cataloging or standard product production task is initiated, and the previously initiated task has not yet been completed, then the task is stopped and the generated data is deleted. If the task has already been completed, then the cataloged formatted data and product data are deleted, retaining only the last cataloged formatted data and product data.

[0133] According to embodiments of the present invention, the optical satellite data processing method further includes, for example:

[0134] S910, based on the first correspondence and / or the second correspondence, replay the historical original bitstream data to obtain the third CCD formatted data covering the target area.

[0135] The S920, based on the observation task, produces standard products from the formatted data of the third CCD. The task of replaying historical raw data streams has a lower priority than the real-time data reception task.

[0136] For example, in ground data processing systems, due to the large amount of remote sensing data acquired daily, a massive storage resource needs to be maintained. Therefore, a common strategy is to permanently store raw data streams, while cataloging and product data are cleaned up and deleted after a period of time. However, remote sensing applications such as change detection require historical data support. In this case, the raw data streams must be replayed to re-execute cataloging and product production tasks and obtain historical data products.

[0137] However, due to the imbalance of stored data, the correspondence between the observation tasks provided by the operation and control system and the raw bitstream data generated by the data receiving tasks is unreliable. Therefore, the data processing system needs to organize the playback tasks according to the relationship between the actual received observation tasks and the data receiving tasks.

[0138] According to an embodiment of the present invention, replaying historical raw bitstream data to obtain third CCD formatted data covering the target area includes, for example:

[0139] S1011, replay the historical raw bitstream data according to the order in which the observation task was actually included in the historical raw bitstream data. Or

[0140] S1012, determine the third data receiving task corresponding to each CCD of the observation task, and replay the historical raw bitstream data according to the receiving order of the third data receiving task.

[0141] For example, the main processing steps for replaying historical raw bitstream data include:

[0142] R51. When replaying the original bitstream data in batches, the original bitstream data is replayed in the order that the observation task actually includes in the original bitstream data.

[0143] In some embodiments, the data processing system needs to reprocess all observation task data within a certain time period, requiring batch playback of raw bitstream data, resulting in a large amount of temporary data storage and task congestion in a short period. To address this, the start times of observation tasks within the processing time period are sorted according to their order of execution. Based on the relationship table between observation tasks and data receiving tasks, the raw bitstream data is played back in the order in which the observation tasks are actually included in the raw bitstream data, ensuring that all CCDs for each observation task are assembled and ready to initiate product production tasks as quickly as possible.

[0144] R52. When it is necessary to replay and obtain cataloged formatted data and product data of a certain observation task, obtain the data receiving task corresponding to each CCD of the observation task, replay the corresponding original code stream data according to the receiving order of the data receiving task, and only initiate all payload cataloging and product production tasks corresponding to the observation task.

[0145] In some embodiments, the raw bitstream data contains data from multiple observation tasks. Playing back the raw bitstream data automatically initiates multiple observation task cataloging and product production tasks. When it is necessary to play back and obtain cataloged formatted data and product data for a specific observation task, the data receiving task corresponding to each CCD of that observation task is obtained, and all corresponding raw bitstream data are played back in the receiving order of the data receiving tasks. After all raw bitstream data channel merging, virtual channel separation, decompression, formatting processing, and the extraction of formatted data from each CCD of that observation task are completed, all payload cataloging and product production tasks corresponding to that observation task are initiated. Other observation task formatted data generated during the playback of raw bitstream data does not initiate subsequent tasks and is directly cleaned up as temporary files to save computing and storage resources.

[0146] According to an embodiment of the present invention, the production of standard products from third CCD formatted data, based on the observation task, includes, for example:

[0147] S1021, Determine the fourth CCD formatted data for one or more payloads corresponding to the observation mission.

[0148] S1022, standard product production is performed on the formatted data of the fourth CCD.

[0149] For example, the main processing steps for replaying historical raw bitstream data also include:

[0150] R53. When it is necessary to replay the observation task cataloging, formatting and product data of a certain payload of an observation task, during the playback of the original bitstream data, after channel merging and virtual channel separation, only the corresponding payload decryption, decompression, formatting, cataloging and product production tasks are initiated.

[0151] In some embodiments, an observation task may include data from simultaneous observations by payloads such as panchromatic, multispectral, infrared, and hyperspectral sensors. Different payloads and different CCDs are transmitted to the ground using different virtual channel codes. When it is necessary to replay the observation task cataloging format and product data of a specific payload of an observation task, the data receiving task corresponding to each CCD of the observation task is obtained, and all the corresponding raw bitstream data is replayed in the receiving order of the data receiving tasks. After channel merging and virtual channel separation are completed, only the corresponding payload decryption, decompression, formatting processing, and formatted data extraction tasks for each CCD of the observation task payload are initiated. After the formatted extraction of each CCD of the observation task payload in all replay tasks is completed, the corresponding payload cataloging and product production tasks of the observation task are initiated. The formatted data of other observation task payloads generated from the replay of raw bitstream data are not subject to subsequent tasks and are directly cleaned up as temporary files to save computing and storage resources.

[0152] R54. The priority of the historical data processing task initiated in steps R51 to R53 is lower than the priority of each processing task initiated by the real-time data receiving task.

[0153] In some embodiments, both the raw bitstream data received in real time and the raw bitstream data played back require tasks such as decryption, channel merging, virtual channel separation, decompression, formatting, cataloging, and 0 / 1 / 2 level product generation, all using the same set of computing and storage resources. To ensure rapid completion of real-time data processing, the priority of each processing stage task initiated in steps R51 to R53 for historical data is lower than the priority of each processing stage task initiated by the real-time data receiving task.

[0154] In summary, this invention proposes an optical satellite data processing method. For emergency point target (small area) observation tasks, as long as a CCD covers the point target slice area, a rapid slice radiometric and geometric positioning task can be initiated to ensure that emergency slice data can be quickly distributed to users. For emergency area (larger area) observation tasks, as long as each CCD meets the requirements for scene product production, CCD formatted data can be stitched together, and subsequent standard product production and distribution tasks can be initiated scene by scene, ensuring that emergency area data is quickly distributed to users and improving the data processing efficiency of emergency observation tasks.

[0155] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of the invention. The appended method embodiments provide elements of various steps in an exemplary order and are not intended to be limited to a specific order or hierarchy.

[0156] It should also be noted that the directional terms mentioned in the embodiments, such as "up," "down," "front," "back," "left," and "right," are only for reference to the directions in the accompanying drawings and are not intended to limit the scope of protection of the present invention. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or constructions will be omitted when they may cause confusion in understanding the present invention. Furthermore, the shapes, sizes, and positional relationships of the components in the drawings do not reflect their actual size, scale, or actual positional relationships.

[0157] In the detailed description above, various features are combined together in a single embodiment to simplify the invention. This disclosure should not be construed as reflecting such an intention.

[0158] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. The term "comprising" as used in the specification is similar in its coverage to the term "including." The use of any term "or" in the specification is intended to indicate "non-exclusive or."

[0159] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for processing optical satellite data, characterized in that, include: Determining the start and end times of a slice for an observation task includes: determining the start and end times of the payload observation for the observation task; determining the start and end times of observation for each CCD based on the payload observation start and end times; determining the first observation time of the payload of the observation task at the center point of the target area; determining the second observation time of each CCD at the center point of the target area based on the payload observation start and end times, the observation start and end times of each CCD, and the first observation time; determining the positions of the four corner points of the slice in the target area and the slice length along the track direction; and determining the start and end times of the slice based on the second observation time, the positions of the four corner points of the slice, and the slice length along the track direction. Based on the slice start and end times, the original bitstream data is extracted to obtain the first CCD formatted data covering the target area. This includes: extracting the initial formatted data of each CCD from the first data receiving task according to the observation start and end times of each CCD, and recording the actual observation start and end times of the observation task; recording the first correspondence between the initial formatted data of each CCD and the original bitstream data; and based on the first correspondence, deduplicating and splicing the initial formatted data of each CCD by frame count to obtain the first CCD formatted data, and updating the actual observation start and end times of the observation task. If the target area is less than or equal to a preset threshold, the first CCD formatted data is sliced ​​to obtain sliced ​​data; If the target area is larger than the preset threshold, the formatted data of the first CCD is spliced ​​together to obtain spliced ​​data; Standard product production is carried out on the sliced ​​data or the stitched data; The observation tasks include emergency observation tasks, and the first CCD formatted data includes formatted data from at least one CCD.

2. The method according to claim 1, characterized in that, When the target area is less than or equal to a preset threshold, slicing the first CCD formatted data to obtain sliced ​​data includes: Determine the relationship between the start and end times of acquiring the first CCD formatted data and the updated start and end times of the actual observation; If the acquisition start and end time is included in the actual observation start and end time, auxiliary data of the first CCD formatted data is extracted according to the acquisition start and end time. Based on the auxiliary data, determine the corner point information of the first CCD formatted data; Based on the corner point information of the first CCD formatted data, the initial slice data is determined; and If the initial slice data intersects with the target region, the initial slice data is subjected to radiometric correction and geometric positioning processing to obtain the slice data.

3. The method according to claim 1, characterized in that, When the target area is larger than the preset threshold, the first CCD formatted data is stitched together to obtain stitched data, including: Determine the coverage area of ​​the first CCD formatted data; Based on the coverage area, the formatted data of the first CCD is spliced ​​together according to the position to obtain the spliced ​​data; The spliced ​​data is greater than or equal to one scene of data.

4. The method according to claim 2, characterized in that, The slice data includes CCD slice data and / or stitched CCD slice data, and the standard product production of the slice data or the stitched data includes: Standard product manufacturing is performed on the CCD slice data; and / or The adjacent CCD slice data are stitched together to obtain the initial stitched CCD slice data; Based on the target area, the initial stitched CCD slice data is cropped to obtain the stitched CCD slice data; The stitched CCD slice data is used to produce standard products.

5. The method according to claim 3, characterized in that, The process of producing standard products from the sliced ​​data or the stitched data includes: Standard product production is performed on the spliced ​​data according to the scene; or Determine the preset number of data reception tasks; If the number of times the second data receiving task is completed reaches the preset number of data receiving tasks, the spliced ​​data is used to produce a standard product.

6. The method according to claim 5, characterized in that, After producing a standard product from the spliced ​​data, the method further includes: Reacquire the second CCD formatted data related to the observation task; Record the second correspondence between the formatted data of the second CCD and the original bitstream data; and Standard product production is carried out on the formatted data of the second CCD.

7. The method according to claim 6, characterized in that, Also includes: Based on the first correspondence and / or the second correspondence, the historical original bitstream data is replayed to obtain the third CCD formatted data covering the target area; Based on the observation task, standard products are produced from the formatted data of the third CCD. Among them, the priority of the task of replaying the historical raw bitstream data is lower than the priority of the real-time data receiving task.

8. The method according to claim 7, characterized in that, The process of replaying historical raw bitstream data to obtain third CCD formatted data covering the target area includes: The historical raw bitstream data is replayed according to the order in which the observation task is actually included in the historical raw bitstream data; or A third data receiving task corresponding to each CCD of the observation task is determined, and the historical raw bitstream data is replayed according to the receiving order of the third data receiving task. The step of producing standard products from the third CCD formatted data according to the observation task includes: Determine the fourth CCD formatted data for one or more payloads corresponding to the observation task; The fourth CCD formatted data is used for standard product production.

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