Calibrating a System of Satellite Instruments - Satellite-based Applications on Climate Change - page 13

Chapter 2
Calibrating a System of Satellite Instruments
Changyong Cao, Ruiyue Chen, and Sirish Uprety
Abstract Satellite instrument calibration is the essential and fundamental process
to convert the Earth view sensor response in voltage and counts to radiance and
reflectance. Calibration accuracy directly affects the quality of the satellite Level 1b
data used for numerical weather prediction and climate change detection. There-
fore, ideally all calibration should be made traceable to the International System of
Units (SI). However, since each satellite instrument is calibrated separately with
different methodologies and at different times in history, there is often disagree-
ment between satellite measurements which could cause errors in both weather and
climate applications. This chapter provides an overview of the fundamentals of
satellite instrument calibration and reviews some of the challenges in establishing
consistent satellite measurements across a system of satellites. Examples are used to
demonstrate the progress made in inter-satellite calibration in recent years to
support climate change detection studies and to contribute to the Global Earth
Observation System of Systems (GEOSS).
Keywords Satellite instrument • Calibration • Accuracy • Consistency