US-12617552-B2 - Earth monitoring system and method of managing a satellite constellation

Abstract

An Earth monitoring system comprises a satellite constellation ( 310 ) and a schedule calculation module ( 302 ) located on Earth. The schedule calculation module ( 302 ) may be configured to implement a satellite management method receiving a request post-launch for a location to be imaged; recalculating an existing schedule of the satellites to provide an updated schedule that includes imaging the location; and providing the updated schedule for transmission to one or more of the satellites.

Inventors

• Rafal Modrzewski
• Pekka Laurila
• Ignacio Chechile

Assignees

• ICEYE OY

Dates

Publication Date

20260505

Application Date

20220923

Priority Date

20210929

Claims (20)

1. 1 . A method of managing a constellation of Earth observation satellites at ground control, each satellite comprising a synthetic aperture radar for imaging Earth, the method comprising: receiving a request post-launch to image a location on a surface of Earth; identifying, from the constellation of satellites, qualifying satellites whose paths enable imaging of the location within a time window; for each qualifying satellite, identifying one or more execution sets, each execution set comprising the qualifying satellite, a ground station for providing an uplink and a ground station for providing a down link for communicating with the qualifying satellite, and at least one of the execution sets comprising: one or more further qualifying satellites for imaging the location using more than one satellite; and respective ground stations for providing an uplink and respective ground stations for providing a downlink for communication with the one or more further qualifying satellites; identifying an optimum execution set for imaging the location within the time window; recalculating an existing schedule of the satellites to provide an updated schedule that includes imaging the location using the optimum execution set; and transmitting the updated schedule to one or more of the satellites to image the location identified in the request.
2. 2 . The method of claim 1 , wherein the constellation of satellites stores the existing schedule.
3. 3 . The method of claim 1 comprising simulating satellite paths to identify the qualifying satellites.
4. 4 . The method of claim 1 , comprising selecting an execution set for imaging the location.
5. 5 . The method of claim 1 , comprising using ground station availability data retrieved from a ground station provider to identify the ground station for providing an uplink or the ground station for providing a down link.
6. 6 . The method of claim 1 , wherein the ground station for providing an uplink and the ground station for providing a down link are different ground stations.
7. 7 . The method of claim 1 , wherein communicating with the qualifying satellite comprises space to space communication.
8. 8 . The method of claim 1 , wherein each execution set is capable of downlinking an image of the location within a predetermined time.
9. 9 . The method of claim 1 , wherein identifying an optimum execution set comprises minimising an order turn around time or a difference between a requested imaging time and a scheduled imaging time.
10. 10 . The method of claim 1 , wherein determining an optimum execution set comprises optimising the updated schedule of the constellation of satellites.
11. 11 . The method of claim 10 , wherein optimising the updated schedule comprises optimising a distribution of utilisation across the constellation of satellites, allocating tasks to the constellation of satellites according to their respective capabilities, or predicting data communication traffic and optimising the updated schedule based on the prediction.
12. 12 . The method of claim 10 , wherein optimising the updated schedule comprises rescheduling a task previously scheduled in the existing schedule only if a predetermined duration remains before it is due to be executed or if agreed service levels can still be met.
13. 13 . The method of claim 1 , comprising booking ground station services from a ground station provider according to the updated constellation schedule.
14. 14 . The method of claim 1 , comprising receiving an image of the location from one or more of the constellation of satellites.
15. 15 . The method of claim 1 , comprising recalculating the updated schedule to provide an adjusted schedule in response to unavailability of one of the satellites, and providing the adjusted schedule for transmission to one or more of the satellites.
16. 16 . The method of claim 1 , comprising recalculating the updated schedule to provide an adjusted schedule in response to unavailability of a scheduled ground station, and providing the adjusted schedule for transmission to one or more of the satellites.
17. 17 . The method of claim 1 , comprising recalculating the updated schedule to provide an adjusted schedule in response to an addition of a satellite to the constellation of satellites, and providing the adjusted schedule for transmission to one or more of the satellites.
18. 18 . A schedule calculation module with a processor and a non-transitory computer readable medium storing instructions which, when executed by the processor cause the schedule calculation module to perform the method of claim 1 .
19. 19 . A non-transitory computer readable storage medium with processor executable instructions stored thereon which, when executed by a processor in a schedule calculation module, causes cause the schedule calculation module to perform a method of managing a constellation of Earth observation satellites at ground control, each satellite comprising a synthetic aperture radar for imaging Earth, wherein the method comprises: receiving a request post-launch to image a location; identifying, from the constellation of satellites, qualifying satellites whose paths enable imaging of the location within a time window; for each qualifying satellite, identifying one or more execution sets, each execution set comprising the qualifying satellite, a ground station for providing an uplink and a ground station for providing a down link for communicating with the qualifying satellite, and at least one of the execution sets comprising: one or more further qualifying satellites for imaging the location using more than one satellite; and respective ground stations for providing an uplink and respective ground stations for providing a down link for communication with the one or more further qualifying satellites; identifying an optimum execution set for imaging the location within the time window; recalculating an existing schedule of the satellites to provide an updated schedule that includes imaging the location using the optimum execution set; and transmitting the updated schedule to one or more of the satellites to image the location identified in the request.
20. 20 . An Earth monitoring system comprising a satellite constellation, each satellite comprising a synthetic aperture radar for imaging Earth, and a schedule calculation module located on Earth, wherein the schedule calculation module is configured to: receive a request post-launch to image a location and identify, from the constellation of satellites, qualifying satellites whose paths enable imaging of the location within a time window; for each qualifying satellite, identify one or more execution sets, each execution set comprising the qualifying satellite, a ground station for providing an uplink and a ground station for providing a down link for communicating with the qualifying satellite, and at least one of the execution sets comprising: one or more further qualifying satellites for imaging the location using more than one satellite; and respective ground stations for providing an uplink and respective ground stations for providing a down link for communication with the one or more further qualifying satellites; identifying an optimum execution set for imaging the location within the time window; recalculate an existing schedule for the satellites in the constellation to provide an updated schedule that includes imaging the location using the optimum execution set, and transmit the updated schedule to one or more of the satellites to image the location identified in the request.

Description

This application is the National Stage filing under 35 U.S.C. 371 of International Application No. PCT/EP2022/076590 filed on 23 Sep. 2022, which claims priority to GB Application No. 2113949.8 filed on 29 Sep. 2021, the contents of both of which are hereby incorporated by reference herein in their entirety to the extent permitted by law. The present application relates to a system and method for Earth observation using a constellation of satellites, and a system for managing and tasking the satellite constellation to acquire images for a range of Earth observation applications. BACKGROUND Many land and maritime monitoring applications require information to be delivered within a few hours or less due to the nature of the events being monitored. For example, this may be required in ship identification and tracking applications used for detecting unauthorised shipping activities where information is required on a fast enough timescale to enable prompt intervention. However, Earth observation satellites for monitoring typically do not return images on such short timescales after a new order is submitted. Instead, it is typical for Earth observation satellites to be tasked before launch such that the mission is predefined. This creates problems for responding to real-time monitoring needs. The embodiments described below are not limited to implementations which solve any or all of the disadvantages of the known approaches described above. SUMMARY This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to determine the scope of the claimed subject matter. The present disclosure provides a method of managing a constellation of satellites that may be performed at ground control, to accommodate a post-launch request for a location to be imaged. Aspects of some implementations include the identification of execution sets for imaging locations, selecting an optimum execution set and accommodating changes to the satellite constellation. In a first aspect, the present disclosure provides a method of managing a constellation of earth observation satellites each comprising a synthetic aperture radar for imaging the earth, the method comprising: receiving a request post-launch to acquire an image of a location; identifying, from the constellation of satellites, qualifying satellites whose paths enable imaging of the location within a time window; for each qualifying satellite, identifying one or more execution sets, each execution set comprising the qualifying satellite and a communication channel for communicating with the qualifying satellite, and at least one of the execution sets comprising one or more further qualifying satellites for imaging the location using more than one satellite; recalculating an existing schedule of the satellites to provide an updated schedule that includes imaging the location; and providing the updated schedule for transmission to one or more of the satellites. The method may include any of the below described features in any combination. The constellation of satellites may store the existing schedule. The method may comprise selecting an execution set for imaging the location. The method may comprise simulating satellite paths to identify the qualifying satellites. Ground station availability data may be used to identify the communication channels of the execution sets. The ground station availability data may be retrieved from a ground station provider. One or more of the communication channels may comprise an uplink and a downlink that use different ground stations. One or more of the communication channels may comprise space to space communication. Each execution set may be capable of downlinking an image of the location within a predetermined time. The method may comprise selecting an optimum execution set for imaging the location. The method may comprise minimising an order turn around time. The method may comprise minimising a difference between a requested imaging time and a scheduled imaging time. Determining an optimum execution set may comprise optimising the updated schedule of the constellation of satellites. Optimising the updated schedule may comprise optimising a distribution of utilisation across the constellation of satellites. Optimising the updated schedule may comprise allocating tasks to the constellation of satellites according to their respective capabilities. Optimising the updated schedule may comprise predicting data communication traffic and optimising the updated schedule based on the prediction. For example prediction may use historic traffic data, for example using machine learning. The optimising the updated schedule may comprise rescheduling a task previously scheduled in the existing schedule. The method may comprise rescheduling the