AVHRR has known navigation problems. Are the positions for the FIMMA layer correct?
A. We run the AVHRR data through the Navigation Correction software before creating the FIMMA product. This software uses Group Control Points (GCP) or known points on the earth and identifies corresponding points on the image. It then “rubber sheets” the image to best match these points. When enough GCPs are found, the navigation correction is successful. When it fails, a several km error can remain in the FIMMA product. You’ll note that we only include counties, interstates and rivers as local layers to help users resolve fire locations. To locate fires to a precision less than a few km, users should contact local land managers, fire fighters and law enforcement personnel.
