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 said first class and said 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 a first class of at least two classes and a brightness temperature for a second class of said at least two classes 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. - 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 said first class and said 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 a first class of at least two classes and a brightness temperature for a second class of said at least two classes 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. - 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.