Method and system for improving the resolution of sensor data

• US 10,643,098 B2
• Filed: 06/13/2017
• Issued: 05/05/2020
• Est. Priority Date: 06/13/2016
• Status: Active Grant

• Current Assignee: Planet Labs PBC
• Original Assignee: VanderSat B.V. (Planet Labs PBC)
• Inventors: De Jeu, Richard Adrianus Maria, De Nijs, Anna Helena Alida, Van Klink, Michel Hendricus Wilibrord
• Primary Examiner(s): Coleman, Stephen P
• Application Number:
  US16/308,741
• Publication Number:
  US 20190347506A1
• Time in Patent Office: 1,057 Days
• Field of Search: 382113
• CPC Class Codes: G06F 18/25 Fusion techniques
• CPC Class Codes: G06T 2207/30181 Earth observation
• CPC Class Codes: G06T 5/73 Deblurring; Sharpening
• CPC Class Codes: G06V 10/80 Fusion, i.e. combining data from various sources at the sensor level, preprocessing level, feature extraction level or classification level multimodal speaker identification or verification G10L17/10
• CPC Class Codes: G06V 20/13 Satellite images

Abstract

The invention relates to a system (51) for improving the spatial resolution of sensor data. The system comprises at least one receiver (53) and at least one processor (55). The at least one receiver (53) is configured to receive a sensor data set and a map. Each element of the sensor data set comprises a sensor footprint identifier allowing a sensor footprint to be identified and a brightness temperature measured for the sensor footprint. The map defines for each of a plurality of geographical areas whether it belongs to one of the first class and the second class. The first class represents a land type and the second class represents a water type. The geographical area is smaller than the sensor footprint. The at least one processor (55) is configured to determine for each element of the sensor data set received using the at least one receiver (53) a brightness temperature for each of at least two classes including the first class and the second class based on the map received using the at least one receiver (53) and to determine a brightness temperature for a specific geographical area of the map based on brightness temperatures associated with a plurality of footprints if the specific geographical area belongs to the first class and based on a brightness temperature determined for the second class if the specific geographical area belongs to the second class. Each of the plurality of footprints covers the specific geographical area.

Claims

1. A computer-implemented method of improving the spatial resolution of sensor data, comprising at least one processor performing the steps of:

receiving a sensor data set, each element of said sensor data set comprising a sensor footprint identifier allowing a sensor footprint to be identified and a brightness temperature measured for said sensor footprint;

receiving a map, said map defining for each of a plurality of geographical areas whether it belongs to one of a first class and a second class, said first class representing a land type, said second class representing a water type and said geographical area being smaller than said sensor footprint;

determining for each element of said sensor data set a brightness temperature for the first class and a brightness temperature for the second class based on said map; and

determining a brightness temperature for a geographical area of said map based on brightness temperatures associated with a plurality of footprints if said geographical area belongs to said first class, each of said plurality of footprints covering said geographical area, and based on a brightness temperature determined for said second class if said geographical area belongs to said second class

wherein the step of determining for each element of said sensor data set said brightness temperature for said first class and said brightness temperature for said second class comprises;

determining a brightness temperature for said second class from a plurality of percentages, said plurality of percentages comprising for each of a plurality of elements of said sensor data set a percentage of at least one footprint associated with said element belonging to said first class and a percentage of said at least one footprint belonging to said second class, and from brightness temperatures associated with said plurality of elements, and

determining for each element of said plurality of elements a brightness temperature for said first class based on said brightness temperature for said second class, said brightness temperature measured for said element, a percentage of at least one footprint associated with said element belonging to said first class and a percentage of said at least one footprint belonging to said second class.

2. The method as claimed in claim 1, wherein the step of determining for each element of said sensor data set said brightness temperature for said first class and said brightness temperature for said second class comprises determining, for each element of said sensor data set, which geographical areas of said map both belong to said first class and are covered by a plurality of footprints associated with said element and which geographical areas of said map both belong to said second class and are covered by said plurality of footprints associated with said element, wherein a geographical area present in a smaller footprint has a higher weight than a geographical area present in a larger footprint in determining a percentage of said at least one footprint belonging to said first class and a percentage of said at least one footprint belonging to said second class.

3. The method as claimed in claim 1, wherein determining said brightness temperature for said geographical area of said map based on said brightness temperatures associated with said plurality of footprints if said geographical area belongs to said first class comprises assigning a higher weight to a brightness temperature associated with a smaller one of said plurality of footprints and a smaller weight to a brightness temperature associated with a larger one of said plurality of footprints.

4. The method as claimed in claim 1, wherein the step of determining for each element of said sensor data set said brightness temperature for said first class and said brightness temperature for said second class comprises determining for each element of said sensor data set, for each of at least one footprint associated with said element, a percentage of geographical areas belonging to said first class which are covered by said footprint arid a percentage of geographical areas belonging to said second class which are covered by said footprint.

5. The method as claimed in claim 4, wherein said at least one footprint comprises a plurality of footprints and the step of determining for each element of said sensor data set said brightness temperature for said first class and said brightness temperature for said second class further comprises determining for each element of said sensor data set an average percentage of geographical areas belonging to said first class and an average percentage of geographical areas belonging to said second class from said percentages determined for each of said plurality of footprints.

6. A computer readable medium for storing instructions when executed on a computer system, perform a method comprising:

receiving a sensor data set, each element of said sensor data set comprising a sensor footprint identifier allowing a sensor footprint to be identified and a brightness temperature measured for said sensor footprint;

receiving a map, said map defining for each of a plurality of geographical areas whether it belongs to one of a first class and a second class, said first class representing a land type, said second class representing a water type and said geographical area being smaller than said sensor footprint;

determining for each element of said sensor data set a brightness temperature for the first class and a brightness temperature for the second class based on said map; and

determining a brightness temperature for a geographical area of said map based on brightness temperatures associated with a plurality of footprints if said geographical area belongs to said first class, each of said plurality of footprints covering said geographical area, and based on a brightness temperature determined for said second class if said geographical area belongs to said second class

wherein the step of determining for each element of said sensor data set said brightness temperature for said first class and said brightness temperature for said second class comprises;

determining a brightness temperature for said second class from a plurality of percentages, said plurality of percentages comprising for each of a plurality of elements of said sensor data set a percentage of at least one footprint associated with said element belonging to said first class and a percentage of said at least one footprint belonging to said second class, and from brightness temperatures associated with said plurality of elements, and

determining for each element of said plurality of elements a brightness temperature for said first class based on said brightness temperature for said second class, said brightness temperature measured for said element, a percentage of at least one footprint associated with said element belonging to said first class and a percentage of said at least one footprint belonging to said second class.

7. The computer readable medium as claimed in claim 6, wherein the step of determining for each element of said sensor data set said brightness temperature for said first class and said brightness temperature for said second class comprises determining, for each element of said sensor data set, which geographical areas of said map both belong to said first class and are covered by a plurality of footprints associated with said element and which geographical areas of said map both belong to said second class and are covered by said plurality of footprints associated with said element, wherein a geographical area present in a smaller footprint has a higher weight than a geographical area present in a larger footprint in determining a percentage of said at least one footprint belonging to said first class and a percentage of said at least one footprint belonging to said second class.

8. The computer readable medium as claimed in claim 6, wherein determining said brightness temperature for said geographical area of said map based on said brightness temperatures associated with said plurality of footprints if said geographical area belongs to said first class comprises assigning a higher weight to a brightness temperature associated with a smaller one of said plurality of footprints and a smaller weight to a brightness temperature associated with a larger one of said plurality of footprints.

9. The computer readable medium as claimed in claim 6, wherein the sensor data set is received from a satellite or drone.

10. The computer readable medium as claimed in claim 6, wherein the sensor data set is suitable for determining soil moisture data.

11. The computer readable medium as claimed in claim 6, wherein the step of determining for each element of said sensor data set said brightness temperature for said first class and said brightness temperature for said second class comprises determining for each element of said sensor data set, for each of at least one footprint associated with, said element, a percentage of geographical areas belonging to said first class which are covered by said footprint and a percentage of geographical areas belonging to said second class which are covered by said footprint.

12. The computer readable medium as claimed in claim 11, wherein said at least one footprint comprises a plurality of footprints and the step of determining for each element of said sensor data set said brightness temperature for said first class and said brightness temperature for said second class further comprises determining for each element of said sensor data set an average percentage of geographical areas belonging to said first class and an average percentage of geographical areas belonging to said second class from said percentages determined for each of said plurality of footprints.

13. A system for improving the spatial resolution of sensor data, comprising:

at least one receiver; and

at least one processor configured;

to use said at least one receiver to receive a sensor data set, each element of said sensor data set comprising a sensor footprint identifier allowing a sensor footprint to be identified and a brightness temperature measured for said sensor footprint,

to use said at least one receiver to receive a map, said map defining for each of a plurality of geographical areas whether it belongs to one of a first class and a second class, said first class representing a land type, said second class representing a water type and said geographical area being smaller than said sensor footprint,

to determine for said each element of said sensor data set a brightness temperature for each of at least two classes including said first class and said second class based on said map, and

to determine a brightness temperature for a geographical area of said map based on brightness temperatures associated with a plurality of footprints if said geographical area belongs to said first class, each of said plurality of footprints covering said geographical area, and based on a brightness temperature determined for said second class if said geographical area belongs to said second class,

wherein said at least one processor is configured to determine for said each element of said sensor data set said brightness temperature for each of said at least two classes by;

determining a brightness temperature for said second class from a plurality of percentages, said plurality of percentages comprising for each of a plurality of elements of said sensor data set a percentage of at least one footprint associated with said element belonging to said first class and a percentage of said at least one footprint belonging to said second class, and from brightness temperatures associated with said plurality of elements, and

determining for each element of said plurality of elements a brightness temperature for said first class based on said brightness temperature for said second class, said brightness temperature measured for said element, a percentage of at least one footprint associated with said element belonging to said first class and a percentage of said at least one footprint belonging to said second class.

14. The system as claimed in claim 13, wherein determining for each element of said sensor data set said brightness temperature for said first class and said brightness temperature for said second class comprises determining, for each element of said sensor data set, which geographical areas of said map both belong to said first class and are covered by a plurality of footprints associated with said element and which geographical areas of said map both belong to said second class and are covered by said plurality of footprints associated with said element, wherein a geographical area present in a smaller footprint has a higher weight than a geographical area present in a larger footprint in determining a percentage of said at least one footprint belonging to said first class and a percentage of said at least one footprint belonging to said second class.

15. The system as claimed in claim 14, determining for each element of said sensor data set said brightness temperature for said first class and said brightness temperature for said second class comprises determining for each element of said sensor data set, for each of at least one footprint associated with said element, a percentage of geographical areas belonging to said first class which are covered by said footprint and a percentage of geographical areas belonging to said second class which are covered by said footprint.

16. The system as claimed in claim 15, wherein said at least one footprint comprises a plurality of footprints and the step of determining for each element of said sensor data set said brightness temperature for said first class and said brightness temperature for said second class further comprises determining for each element of said sensor data set an average percentage of geographical areas belonging to said first class and an average percentage of geographical areas belonging to said second class from said percentages determined for each of said plurality of footprints.

17. The system as claimed in claim 16, wherein determining said brightness temperature for said geographical area of said map based on said brightness temperatures associated with said plurality of footprints if said geographical area belongs to said first class comprises assigning a higher weight to a brightness temperature associated with a smaller one of said plurality of footprints and a smaller weight to a brightness temperature associated with a larger one of said plurality of footprints.

18. The system as claimed in claim 17, wherein the receiver is configured to receive sensor data set is received from a satellite or drone.