Creating a Cropland Data Layer for an Entire State

A collection of Landsat scenes corresponding to an entire state or a major portion of a state, are categorized based on ground truth information collected from farmers by USDA enumerators. However, no farmer reported data is revealed or derivable from the categorized Landsat scenes due to confidentiality protections. The individual categorized Landsat scenes need to be geo-referenced and stitched together to a common ortho-rectified base in order to be released as a public use GIS file. EarthSat Inc.’s GeoCover stock mosaic was chosen as the ortho base, because the GeoCover product offered accuracy and vast coverage over all of our project areas. The registration of the GeoCover mosaicked scene and the individual raw input scenes are used to get an approximate correspondence. A correlation procedure is used on the raw Landsat scenes and the mosaicked scene to get an exact mapping of each pixel from the input Landsat scenes to the mosaicked scene. The results of the correlation are used to remap the pixels from the individual input scenes into the coordinate system of the mosaicked scene. The image analyst then specifies the mosaic priorities for scene placement, and the mosaic process begins by using the polynomials from the correlation to place the categorized pixels. A classified ortho-rectified mosaicked image is then output for distribution into the public domain.