ABSTRACT
MODTRAN Moderate resolution atmospheric transmission NASA National Aeronautics and Space Administration NIST National Institute of Standards and Technology NOAA National Oceanic and Atmospheric
Administration NOMAD Networked online mapping of atmospheric data NRC National Research Council PSF Point spread function QA4EO Quality Assurance Framework for Earth
Observation SI International system of units SRBC Solar-radiation-based calibration TM Ÿematic Mapper TOA Top of atmosphere TRUTHS Traceable Radiometry Underpinning Terrestrial
and Helio Studies UTM Universal Transverse Mercator WGCV Working Group on Calibration and Validation
Acronyms and De¦nitions ...................................................................................................................87 3.1 Introduction .............................................................................................................................. 88 3.2 Need for Data Standardization ............................................................................................... 88 3.3 Overview .....................................................................................................................................89 3.4 Sensor Radiometric Calibration ............................................................................................. 90
3.7 Spectral Characterization .........................................................................................................97 3.8 Normalization Approaches ......................................................................................................97 3.9 Processing Considerations .......................................................................................................97 3.10 Discussion of Future Trends ....................................................................................................97 3.11 Concluding Remarks .................................................................................................................98 Acknowledgments ................................................................................................................................ 99 References .............................................................................................................................................. 99
Modern-day remote sensing satellite systems yield high-quality digital images that provide both synoptic and detailed observations of the Earth from space. Ÿe steps that have led to this unprecedented geospatial technology are many, and even a summary of that development is beyond the scope of this chapter. Details of the key historical elements of Earth observation remote sensing, such as aviation, rockets, space travel, orbiting satellites, imaging, and lunar and planetary exploration, can be found in numerous books (e.g., Burrows, 1999; Kramer, 2001; Jensen, 2006). Nonetheless, it is worth noting that it has long been known that seeing our planet from above brings signi¦cant advantages.*
Countless applications of satellite imagery have been and continue to be developed, the vast majority for qualitative, everyday uses that bene¦t nevertheless from the laboratory geometric and radiometric quality of the digital images available. Ÿat said, there is also tremendous interest in the quantitative use of satellite images to retrieve and monitor information about the current and changing states of geophysical and biophysical variables, particularly those involved in climate, Earth resources, and environment. Applications include, but are not limited to, vegetation analysis (e.g., agriculture, forestry, precision farming), disaster monitoring, environmental monitoring, watershed management, urban growth analysis, bathymetry, geological mapping, mineral exploration, and intelligence data gathering. In that light, this chapter outlines the key considerations that need to be addressed to ensure that terrestrial variables derived from satellite sensor systems operating in the solar-re©ective optical domain are calibrated radiometrically to a common physical scale.
