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Landsat 7 on-orbit modulation transfer function estimation

December 12, 2001

The Landsat 7 spacecraft and its Enhanced Thematic Mapper Plus (ETM+) were launched on April 15, 1999. Pre-launch modeling of the ETM+ optical system predicted that modulation transfer function (MTF) performance would change on-orbit. A method was developed to monitor the along-scan MTF performance of the ETM+ sensor system using on-orbit data of the Lake Pontchartrain Causeway in Louisiana. ETM+ image scan lines crossing the bridge were treated as multiple measurements of the target taken at varying sampling phases. These line measurements were interleaved to construct an over-sampled target profile for each ETM+ system transfer function. Model parameters were adjusted to achieve the best fit between the simulated profiles and the image measurements. The ETM+ modulation at the Nyquist frequency and the full width at half maximum of the point spread function were computed from the best-fit system transfer function model. Trending these parameters over time revealed apparent MTF performance degradation, observed mainly in the 15-meter resolution ETM+ panchromatic band. This confirmed the pre-launch model prediction that the panchromatic band was the most sensitive to changes in ETM+ optical performance.

Citation Information

Publication Year 2001
Title Landsat 7 on-orbit modulation transfer function estimation
DOI 10.1117/12.450647
Authors James C. Storey
Publication Type Conference Paper
Publication Subtype Conference Paper
Series Title
Series Number
Index ID 70231707
Record Source USGS Publications Warehouse
USGS Organization Earth Resources Observation and Science (EROS) Center