Determining gas concentration near planetary surfaces

A method of determining gas concentration at a region of a planetary surface, comprising the steps of:

• providing a gas filter correlation radiometry (GFCR) system at a location above a planetary surface having an atmosphere illuminated by celestial light wherein the celestial light passes through the atmosphere and reflects off the planetary surface as reflected light, wherein at least a portion of the atmosphere resides between the location and the planetary surface, said GFCR system including a processor and a GFCR sensor having a first gas cell containing a target gas and a second gas cell wherein said second gas cell does not contain said target gas;
• detecting, using said GFCR sensor, the reflected light associated with a region of the planetary surface;
• generating, using said GFCR sensor, first images of the region based on the reflected light passing through said first gas cell and second images of the region based on the reflected light passing through said second gas cell;
• providing said processor with data on altitude variations of the region indicative of a terrain elevation map of the region;
• generating, using said processor, ratio images for the region using said first images and said second images;
• and
• iteratively generating, using said processor, a derived terrain elevation map of the region using said ratio images and values for a mixing ratio of said target gas and a column abundance of said target gas wherein concentration of said target gas above the region is indicated when a best fit is achieved between said terrain elevation map and said derived terrain elevation map.

A system for determining gas concentration at a region of a planetary surface, comprising:

• a platform disposed at a location above a planetary surface;
• a gas filter correlation radiometry (GFCR) system disposed on said platform, said GFCR system including a processor and a GFCR sensor having a first gas cell containing a target gas and a second gas cell wherein said second gas cell does not contain said target gas, said GFCR sensor directed towards a region of the planetary surface, said GFCR sensor generating first images of the region captured through said first gas cell and second images of the region captured through said second gas cell;
• a database of known altitude variations indicative of a terrain elevation map of the region, said database being coupled to said processor;
• said processor generating ratio images of the region using said first images and said second images;
• and
• said processor iteratively generating a derived terrain elevation map of the region using said ratio images and values for a mixing ratio of said target gas and a column abundance of said target gas wherein concentration of said target gas above the region is indicated when a best fit is achieved between said terrain elevation map and said derived terrain elevation map.

A system for determining gas concentration at a region of a planetary surface, comprising:

• a gas filter correlation radiometry (GFCR) system adapted to be disposed on a platform at a location above a planetary surface, said GFCR system including a processor and a GFCR sensor having a first gas cell containing a target gas and a second gas cell wherein said second gas cell does not contain said target gas, said GFCR sensor directed towards a region of the planetary surface, said GFCR sensor generating first images of the region captured through said first gas cell and second images of the region captured through said second gas cell;
• a database of known altitude variations indicative of a terrain elevation map of the region, said database being coupled to said processor;
• said processor generating ratio images of the region using said first images and said second images;
• and
• said processor iteratively generating a derived terrain elevation map of the region using said ratio images and values for a mixing ratio of said target gas and a column abundance of said target gas wherein concentration of said target gas above the region is indicated when a best fit is achieved between said terrain elevation map and said derived terrain elevation map.