Geometric and Radiometric Correction of MOS-1 Imagery in a Canadian Processing System
Brain Robert and Kelly Wiebe
Mac Donald Dettwiler & Associates Ltd.
13800 Commerce Parkway, Richmond, B.C.
Canada V6V 2J3
Abstract
The Marine Observation Satellite (MOS-1) has been operational and routinely acquiring data for over 30 months. As part of the MOS-1 verification project, the Canadian Centre for Remote Sensing (CCRS) has
acquired over 160 orbits of MOS-1 data. Preliminary analysis of the raw data has shown that in order to effectively utilize the imagery, it must first
be processed to correct for radiometric and geometric errors. To meet this need, Mac Donald Dettwile has developed a prototype MOS-1 correcting system capable of radio metrically and geometrically correcting raw MOS-1 data. This paper reviews the Canadian MOS-1 processing capabilities. it begins with a review of the MOS-1 sensors and mage characteristics. Following this, the radiometric and geometric correction algorithms of the Canadian proto type system are described. Finally example of the processed imagery are pre4sented.
1 Introduction
Since its lunch on
February 19, 1987, the marine Observation satellite 9mOS-1) has been routinely acquiring data over north America. As part of the MOS-1 verificat6ion project, the Canadian Centre for Remote Sensing (CCRS) has tracked over 160 orbits of MOS-1 data from which test scenes have been chosen for sensor evaluation and application studies. preliminary valuation of the raw data imagery generated by the CCRS Quick look Transcription System (Butlin 89) indicated that in order to effectively analyze the data, it would first have to be processed to correct for radio metric and geometric errors. The goal of the current project is to provide corrected data for Canadian researches to assess the quality and utility of mjoS-1, and provide CCRS with limited moS-1 processing capabilities to meet further processing needs on an interim basis.
To meet this need, Mac Donald Dettwiler has developed a prototype radiometric and geometric correction system capable of processing data from all three MOS-1 sensors. The system, which is based on Mac Donald Dettwiler’s Geocoded Image Correction System 9gics0 engine, takes as input raw MOS-1 data on LGSOWG format computer compatible tapes (CCTs) generated by the CCRS Transcription System. Raw image data is absolutely radio metrically calibrated, geometrically corrected to a map projection, and output on LGSOWG format CCTs . The geometric processing resample the image to a map projection correcting for distortions introduced in the image acquisition process including sensor alignment, band mis registration, earth curvature and rotation effects, satellite orbit and attitude errors, and temperature dependent sensor characteristics. The radiometric processing converts the raw digital numbers 9dns) to physical units 9radiance or temperature0 correcting for temperature dependent sensor characteristics using both in flight sensor calibration data and preflight information.
This paper describes the Canadian processing of mos-1 data. The three mos-1 sensors are reviewed with emphasis on the quality of the raw image data. The radiometric and geometric correction algorithms of the Canadian prototype system are then discussed following which examples of processed imagery presented.
