Global earth mapping with NASA’s Multi-angle Imaging SpectroRadiometer (MISR)

The Multi-angle Imaging SpectroRadiometer (MISR) is a part of the payload for NASA’s Terra spacecraft launched in December 1999. The MISR instrument continuously acquires a systematic, global, multi-angle imagery in reflected sunlight in order to support and improve studies of the Earth ecology and climate. This paper focuses on the photogrammetric aspect of the data production and discusses quality of the global mapping as evaluated during the first two years of the mission. Usually, remote sensing image data has been only radiometrically and spectrally corrected, as a part of standard processing, prior to being distributed to investigators. In the case of the spaceborne MISR instrument with its unique configuration of nine fixed pushbroom cameras, continuous and autonomous coregistration and geolocation of image data are required prior to application of scientific retrieval algorithm. In order to address this problem, the MISR ground data processing system includes photogrammetric processing. From the entire MISR production system, three segments can be singled out as photogrammetric in nature. These are 1) in-flight geometric calibration, 2) georectification, and 3) cloud height retrieval. The data obtained through in-flight geometric calibration significantly simplify georectification part of the standard processing. Georectification gives fundamental input to scientific retrieval including cloud-top height retrieval.