Suomi NPP VIIRS prelaunch and on-orbit geometric calibration and characterization

Abstract

The Visible Infrared Imaging Radiometer Suite (VIIRS) sensor was launched 28 October 2011 on the Suomi National Polar-orbiting Partnership (SNPP) satellite. VIIRS has 22 spectral bands covering the spectrum between 0.412 μm and 12.01 μm, including 16 moderate resolution bands (M-bands) with a nominal spatial resolution of 750 m at nadir, five imaging resolution bands (I-bands) with a nominal spatial resolution of 375 m at nadir, and a day-night band (DNB) with a near-constant nominal 750 m spatial resolution throughout the scan. These bands are located in a visible and near-infrared focal plane assembly (FPA), a shortwave and midwave infrared FPA, and a long-wave infrared FPA. All bands, except the DNB, are coregistered for proper environmental data records retrievals. Observations from VIIRS instrument provide long-term measurements of biogeophysical variables for climate research and polar satellite data stream for the operational community's use in weather forecasting and disaster relief and other applications. Well Earth-located (geolocated) instrument data are important to retrieving accurate biogeophysical variables. This paper describes prelaunch pointing and alignment measurements, and the two sets of on-orbit correction of geolocation errors, the first of which corrected error from 1300 m to within 75 m (20% I-band pixel size) and the second of which fine-tuned scan-angle dependent errors, bringing VIIRS geolocation products to high maturity in one and a half years of the SNPP VIIRS on-orbit operations. Prelaunch calibration and the on-orbit characterization of sensor spatial impulse responses and band-to-band coregistration are also described. Key Points VIIRS geolocation errors are corrected by a control point matching program Sensor geometry and spatial response is characterized Geolocation of other VIIRS bands is transferred by band-to-band co-registration ©2013 The Authors. Journal of Geophysical Research: Atmospheres published by Wiley on behalf of the American Geophysical Union.