# US 11,029,411 B2 · Method and apparatus for correcting satellite imaging time > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,029,411 B2 - Document ID: US11029411B2 - Status: Granted - Kind: B2 - Application number: 16/009,008 - Filed: 2018-06-14 - Published: 2018-12-27 - Granted: 2021-06-08 - Earliest claimed: 2017-06-27 - Assignees: Korea Aerospace Research Institute - Applicants: Korea Aerospace Research Institute - Inventors: Seon Ho Lee; Jae Cheol Yoon; Dae Kwan Kim - Web page: https://patentgrep.com/patent/US11029411B2 ## CPC - G01S 19/256: {relating to timing, e.g. time of week, code phase, timing offset} - G01S 19/24: Acquisition or tracking {or demodulation} of signals transmitted by the system {(synchronisation aspects of direct sequence spread spectrum modulation H04B1/7073)} - B64G 1/10: Artificial satellites; Systems of such satellites; Interplanetary vehicles (space shuttles B64G1/14) - B64G 1/1028: {using optical means for mapping, surveying or detection, e.g. of intelligence} - B64G 1/242: {Orbits and trajectories} - B64G 1/36: using sensors, e.g. sun-sensors, horizon sensors - G01S 19/246: {involving long acquisition integration times, extended snapshots of signals or methods specifically directed towards weak signal acquisition} - G06T 1/0007: {Image acquisition} - G06T 2207/10044: Radar image - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - B64G: COSMONAUTICS; VEHICLES OR EQUIPMENT THEREFOR - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL ## Abstract Disclosed is a method and apparatus for correcting a satellite image acquisition time. The method may include receiving, from a ground-based orbit propagator, an initially predicted imaging time, a correction command execution time, and a desired satellite position for imaging, and calculating a waiting time for imaging, a predicted satellite position, a correction time, and a corrected imaging time to correct a satellite image acquisition time. ## Claims ### Claim 1 A method of correcting a satellite image acquisition time to be implemented by a computer, the method comprising: receiving, from a ground-based orbit propagator, a desired satellite position for imaging; receiving, from a ground-based orbit propagator or a satellite-based orbit propagator, an initially predicted imaging time (TII) and a correction command execution time (TCorrect), calculating a waiting time for imaging; obtaining a correction point-based satellite position from a satellite positioning system receiver, the correction point-based satellite position being a position of the satellite at the correction command execution time; calculating a predicted satellite position using the correction point-based satellite position, the predicted satellite position being a position of the satellite at a time at which the waiting time elapses after the correction command execution time; calculating a correction time; and calculating a corrected imaging time. ### Claim 2 (depends on 1) The method of claim 1, wherein the calculating of the waiting time comprises: calculating the waiting time based on a difference between the initially predicted imaging time and the correction command execution time. ### Claim 3 (depends on 1) The method of claim 1, wherein the calculating of the predicted satellite position comprises: calculating the predicted satellite position using a satellite-based orbit propagator. ### Claim 4 (depends on 1) The method of claim 1, wherein the calculating of the correction time comprises: calculating the correction time by dividing a difference between the desired satellite position and the predicted satellite position by a satellite velocity. ### Claim 5 (depends on 1) The method of claim 1, wherein the calculating of the correction time comprises: calculating the correction time by dividing a difference between the desired satellite position and the correction point-based satellite position by a satellite velocity. ### Claim 6 (depends on 1) The method of claim 1, wherein the calculating of the corrected imaging time comprises: calculating the corrected imaging time by adding the correction time to the correction command execution time or the initially predicted imaging time. ### Claim 7 (depends on 1) The method of claim 1, wherein the satellite positioning system receiver is configured to receive the correction point-based satellite position from one of a global positioning system (GPS), a global navigation satellite system (GLONASS), and a Galileo system. ### Claim 8 An apparatus for correcting a satellite image acquisition time to be implemented by a computer, the apparatus comprising: a processor configured to: receive a desired satellite position for imaging from a ground-based orbit propagator, receive an initially predicted imaging time and a correction command execution time from the ground-based orbit propagator or a satellite-based orbit propagator, calculate a waiting time for imaging, calculate a predicted satellite position using a correction point-based satellite position, the predicted satellite position being a position of the satellite at a time at which the waiting time elapses after the correction command execution time, calculate a correction time, and calculate a corrected imaging time; and a satellite positioning system receiver configured to receive the correction point-based satellite position from a satellite positioning system, the correction point-based satellite position being a position of the satellite at the correction command execution time. ### Claim 9 (depends on 8) The apparatus of claim 8, wherein the processor is further configured to calculate the waiting time based on a difference between the initially predicted imaging time and the correction command execution time. ### Claim 10 (depends on 8) The apparatus of claim 8, wherein the processor is further configured to calculate the predicted satellite position using a satellite-based orbit propagator. ### Claim 11 (depends on 8) The apparatus of claim 8, wherein the processor is further configured to calculate the correction time by dividing a difference between the desired satellite position and the predicted satellite position by a satellite velocity. ### Claim 12 (depends on 8) The apparatus of claim 8, wherein the processor is further configured to calculate the correction time by dividing a difference between the desired satellite position and the correction point-based satellite position by a satellite velocity. ### Claim 13 (depends on 8) The apparatus of claim 8, wherein the processor is further configured to calculate the corrected imaging time by adding the correction time to the correction command execution time or the initially predicted imaging time. ### Claim 14 (depends on 8) The apparatus of claim 8, wherein the satellite positioning system is one of a global positioning system (GPS), a global navigation satellite system (GLONASS), and a Galileo system. ### Claim 15 (depends on 1) A non-transitory computer-readable storage medium storing instructions that, when executed by a processor, cause the processor to perform the method of claim 1.