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

• Published in: Journal of geophysical research. Atmospheres Vol. 118; no. 20; pp. 11,508 - 11,521
• Main Authors: Wolfe, Robert E., Lin, Guoqing, Nishihama, Masahiro, Tewari, Krishna P., Tilton, James C., Isaacman, Alice R.
• Format: Journal Article
• Language: English
• Published: 27.10.2013
• Subjects: Band‐to‐band co‐registration; Control Point Matching; geolocation; pointing; Spatial Response; VIIRS
• ISSN: 2169-897X; 2169-8996
• DOI: 10.1002/jgrd.50873

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