If no value is specified, the search strategy uses a default dependent on the scene type.
Specifies the distance, in pixels, in the X- and Y-directions of a starting location on the reference image, over which the search for the best match with a fixed point on the input image will be conducted. The distance in pixels is based on the pixel size of the raw images. For example, if the reference data has a resolution of 2 m, and the raw scene has a resolution of 4 m, and the nominal model has an error of no more than 1600 m, a search radius of 1600/4 = 400 or larger would suffice. Further, if the search radius is less than 200 pixels, it will be rounded up to 200 pixels. The DEM extracted (that is to be used for orthorectification) from the reference DEM is created with a buffer around it of the size of the search radius.
Specifies the minimum correlation score required to accept a local match between the input and reference images as a GCP. In order for a match to become a GCP, its match score must be greater than the specified value.
Acceptable values range from 0 to 1; the default value of 0.75 is a good score and tends to result in few mismatches, but you may increase this value to ensure better matches. Setting the minimum score to below 0.70 will result in many mismatches and is not recommended. This value is highly sensitive, and should be changed only in very small increments, and with caution.
Specifies the maximum number of GCPs that will be accepted during automatic GCP collection.
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