Landsat-7 ETM+ on-orbit reflective-band radiometric stability and absolute calibration

Launched in April 1999, the Landsat-7 Enhanced Thematic Mapper Plus (ETM+) instrument is in its sixth year of operation. The ETM+ instrument has been the most stable of any of the Landsat instruments. To date, the best onboard calibration source for the reflective bands has been the Full Aperture Solar Calibrator, a solar-diffuser-based system, which has indicated changes of between 1% to 2% per year in the ETM+ gain for bands 1-4 and 8 and less than 0.5%/year for bands 5 and 7. However, most of this change is believed to be caused by changes in the solar diffuser panel, as opposed to a change in the instrument's gain. This belief is based partially on vicarious calibrations and observations of "invariant sites", hyperarid sites of the Sahara and Arabia. Weighted average slopes determined from these datasets suggest changes of 0.0% to 0.4% per year for bands 1-4 and 8 and 0.4% to 0.5% per year for bands 5 and 7. Absolute calibration of the reflective bands of the ETM+ is consistent with vicarious observations and other sensors generally at the 5% level, though there appear to be some systematic differences.

[1]  Brian L. Markham,et al.  Landsat-7 Enhanced Thematic Mapper plus radiometric calibration , 1997 .

[2]  John R. Schott,et al.  Landsat TM and ETM+ thermal band calibration , 2003, SPIE Optics + Photonics.

[3]  B. Markham,et al.  Monitoring large-aperture spherical integrating sources with a portable radiometer during satellite instrument calibration , 1998 .

[4]  Kurtis J. Thome,et al.  Intercomparison of ETM+, MODIS, and SeaWiFS using a land test site , 2003, SPIE Remote Sensing.

[5]  Brian L. Markham,et al.  On-orbit performance of the Landsat-7 ETM+ radiometric calibrators , 2003 .

[6]  Kurtis J. Thome,et al.  Radiometric calibration of MODIS with reference to Landsat-7 ETM+ , 2002, Optics + Photonics.

[7]  D. R. Wilkes.  Thermal Control Surfaces Experiment , 1999 .

[8]  Michael J. Choate,et al.  Effects of Landsat 5 Thematic Mapper and Landsat 7 Enhanced Thematic Mapper plus radiometric and geometric calibrations and corrections on landscape characterization , 2001 .

[9]  Madeleine Bodilis,et al.  SPOT multitemporal calibration over stable desert areas , 1993, Defense, Security, and Sensing.

[10]  M. Leroy,et al.  Selection and characterization of Saharan and Arabian desert sites for the calibration of optical satellite sensors , 1996 .

[11]  Royal Greenwich Observatory,et al.  The Astronomical Almanac for the year 2003 , 1999 .

[12]  K. Thome.  Absolute radiometric calibration of Landsat 7 ETM+ using the reflectance-based method , 2001 .

[13]  B. Holben,et al.  NOAA-11 AVHRR visible and near-IR inflight calibration , 1990 .

[14]  Dennis L. Helder,et al.  Landsat-5 TM and Landsat-7 ETM+ absolute radiometric calibration using the reflectance-based method , 2004, IEEE Transactions on Geoscience and Remote Sensing.