Edge-based correlation image registration algorithm for the Multispectral Thermal Imager (MTI)

Abstract

The Multispectral Thermal Imager Satellite (MTI), launched on March 12, 2000, is a multispectral pushbroom system that acquires 15 unique spectral bands of data from 0.45-10.7 microns, with resolutions of 5 m for the visible bands and 20 m for the infrared. Scene data are collected on three separate sensor chip assemblies (SCAs) mounted on the focal plane. The process of image registration for MTI satellite imagery therefore requires two separate steps: (1) the multispectral data collected by each SCA must be coregistered and (2) the SCAs must be registered with respect to each other. An automated algorithm was developed to register the MTI imagery. This algorithm performs a phase correlation on edge-maps generated from paired bands of data and then spatial-filters the result to calculate the relative shifts between bands. The process is repeated on every combination of band pairs to generate a vector of coregistration results for each SCA. The three SCAs are then registered to each other using a similar process operating on just one spectral band. The resulting registration values are used to produce a linearly shifted un-resampled coregistered image cube. This study shows the results of 791 image registration attempts using the EdgeReg registration code and compares them to a perfect reference data set of the same images registered manually.