Atmospheric compensation in satellite imagery
AssigneeDigitalGlobe, Inc.
InventorFabio Pacifici
Life of this patent
Estimating the term…
Abstract
Techniques for atmospheric compensation in satellite imagery that include converting an image including an array of radiance values to an array of surface reflectance values. The conversion is performed in an automated fashion by identifying one or more portions of the image for which the surface reflectance can be estimated and determining the Aerosol Optical Depth (AOD) by iteratively comparing the radiance value captured by the image sensor to a calculated radiance value (based on the known surface reflectance, historical values for other atmospheric parameters, and the AOD) and adjusting the AOD until the calculated radiance value is substantially the same as the captured radiance value.
Claims22
A method of compensating for atmospheric events in satellite images, comprising:
- receiving image data representing an image of at least a portion of the Earth based on the radiance received by a sensor on the satellite, wherein the image data is pixelated and each pixel represents light directed along a path from a target region on the Earth to the sensor, with other portions on the Earth being non-target regions;
- receiving Earth coordinate data related to the image data for the image;
- receiving temporal data related to the image data for the image;
- retrieving one or more atmospheric characteristics from a database, the one or more atmospheric characteristics from the retrieving being based on the earth coordinate data and the temporal data;
- processing the image data for the image to determine Aerosol Optical Depth (AOD) for the image and without using image data from another image, wherein the processing comprises deriving the determined AOD using a previous AOD value and the one or more atmospheric characteristics from the retrieving as inputs, wherein separate values of AOD are determined for different portions of the image;
- and
- converting the image from radiance to surface reflectance, wherein the converting comprises using the determined separate values of AOD for the different portions of the image.
A method of compensating for atmospheric events in satellite images, comprising:
- receiving image data representing an image of at least a portion of the Earth based on the radiance received by a sensor on the satellite, wherein the image data is pixelated and each pixel represents light directed along a path from a target region on the Earth to the sensor, with other portions on the Earth being non-target regions;
- receiving Earth coordinate data related to the image data for the image;
- receiving temporal data related to the image data for the image;
- retrieving one or more atmospheric characteristics from a database, the retrieving being based on the earth coordinate data and the temporal data;
- processing the image data for the image to determine Aerosol Optical Depth (AOD) for the image, without using image data from another image, wherein separate values of AOD are determined for different portions of the image;
- and
- converting the image from radiance to surface reflectance by using the determined separate values of AOD for the different portions of the image;
- wherein the converting operation includes correcting for light that satisfies each of the following:
- (1) has been scattered at least a first time by the atmosphere onto one of the non-target regions, (2) has then been reflected by the one of the non-target regions, and (3) has then been scattered at least a second time by the atmosphere onto the path to the sensor;
- and
- wherein the determining of AOD on a pixel-by-pixel basis includes using kriging modeling.
Dependencies are inferred from the claim text.