Rectification and registration of remotely sensed data

An important problem in any onboard imaging system is the rectification and registration of images generated by onboard sensors. Accurate registration is a key requirement for detecting changes (in position, brightness, texture, boundary, etc.), from one sensed image to the next, as well as classification of data for intelligence gathering and vehicle guidance. This report discusses techniques of finding match points in pairs of images and performing geometric corrections and unwarping to compensate for systematic and random variations in the flight path, ephemeris, and sensor response. Techniques of resampling and interpolation of image data are reviewed, and the particular characteristics of sensors operating over a wide spectrum from visible through infrared and microwave are discussed. Particular attention is given to the rectification and registration of synthetic aperture radar (SAR) imagery, and several future study tasks on this specialized area are outlined.