Author
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BRYANT, R. - UNIVERSITY OF ARIZONA |
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Moran, Mary |
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Submitted to: IEEE IGARSS Annual Proceedings
Publication Type: Proceedings Publication Acceptance Date: 8/2/2002 Publication Date: 8/2/2002 Citation: Bryant, R., Moran, M.S. 2002. Data continuity of landsat-4 tm, landsat-5 tm, landsat-7 tm, landsat-7etm, and eo-1 advanced aland imager (ali) sensors. Proc. IEEE IGARSS Annual Conf., Toronto Canada, June 24-28, 2002, 3 p. Interpretive Summary: Satellites have been used to monitor the environment for decades. One NASA satellite program, Landsat, was started on 1972. The Landsat program was developed specifically for monitoring the earth¿s land masses. This is an extremely important program because it lets us know how the earth is changing over time. Since the beginning of the program NASA has launched several satellites. Due to technological advances, the specifications of the different sensors have changed. It is very important that the information that researchers are gleaning from the sensors is not biased due to sensor differences. This research looked at the two most recent Landsat sensors and one experimental sensor that is expected to be very similar to the next Landsat sensor. We were able to determine that, for these three sensors, the information acquired from them is not influenced significantly by sensor differences. Therefore these sensors are very good sources of data for studying the earth over time Technical Abstract: In 1982, NASA launched Landsat 4 as part of their on-going Landsat Program. Landsat 5 was launched in 1984, and Landsat 7, the current satellite acquiring images on a global scale, was launched in 1999. In the fall of 2000, NASA launched the Advanced Land Imager (ALI) as a part of the Earth Observation Mission (EO-1). One purpose of the EO-1 Mission is to test new technology which could be used for the Thematic Mapper (TM) sensor on the upcoming Landsat 8 satellite. This suite of sensors provides the public with uninterrupted images of the Earth¿s land surface for nearly twenty years. Current research in areas such as land use change and global climate change require reliable information about the Earth over many years. We analyzed images from the Landsat 4 TM, Landsat 5 TM, Landsat 7 Enhanced TM Plus (ETM+) and EO-1 ALI by comparing ground-based and satellite-derived surface reflectance of agricultural targets. Reflectance was retrieved from the satellite sensor measurements based on a mixture of ground and atmospheric measurements and a radiative transfer model. The reflectances retrieved from all four sensors compared well, although some discrepancies were observed in band 1 between Landsat 4 TM and Landsat 5 TM as well as for band 6 between Landsat 7 ETM+ and ALI sensors. This work documents the uncertainty in data continuity for the historic series of Landsat TM and ETM+ sensors, and provides a quantitative evaluation of data acquired with new ALI technology relative to measurements made by the Landsat sensors. |
