Title :
A New Method for Suomi-NPP VIIRS Day–Night Band On-Orbit Radiometric Calibration
Author :
Shihyan Lee ; McIntire, Jeff ; Oudrari, Hassan ; Schwarting, Thomas ; Xiaoxiong Xiong
Author_Institution :
Sigma Space Corp., Lanham, MD, USA
Abstract :
The Suomi National Polar-orbiting Partnership Visible Infrared Imaging Radiometer Suite (S-NPP VIIRS) instrument contains a visible imaging band designed to produce imagery during both daytime and nighttime, which is called the day-night band (DNB). The DNB is a three-gain-stage backside-illuminated charge-coupled device (CCD) with four detector arrays that aggregate the individual CCD pixels into 32 different aggregation modes across scan, yielding imagery with a roughly constant horizontal sampling interval. The highest gain stage is over 100 000 times more sensitive than the lowest gain stage; the combination of the three gain stages allows for imagery with radiances ranging from 10-10 to 10-2 W · cm-2 · sr-1. The initial DNB on-orbit calibration relies on monthly sensor special operations. This offline calibration approach results in discrete calibration and the loss of some science data. In this paper, we will present a new calibration method based solely on VIIRS onboard calibrators (OBCs). The calibrator data collected on the nighttime side of an orbit are used to determine the dark offset and the data collected over the daytime side of the orbit, and the day-night terminators are used to compute the cross-stage gain ratios. The results showed that the dark offset and the gain ratio derived from the initial method could be biased up to ten digital numbers (DN) and 12%, respectively, due to nighttime airglow and Earth scene stray light. The calibration is also continuous as calibrator data are recorded for each scan. Because no special operation and offline analysis are required, this method was approved for VIIRS operational implementation to improve the DNB radiometric calibration and sensor on-orbit operations.
Keywords :
calibration; charge-coupled devices; geophysical equipment; geophysical techniques; radiometry; DNB; DNB radiometric calibration; Earth scene stray light; OBC; S-NPP VIIRS instrument; Suomi National Polar-orbiting Partnership; Suomi-NPP VIIRS day-night band on-orbit radiometric calibration method; VIIRS onboard calibrators; VIIRS operational implementation; Visible Infrared Imaging Radiometer Suite; aggregation mode; calibration method; calibrator data; cross-stage gain ratio computation; dark offset; dark offset determination; day-night terminator; daytime image; detector array; discrete calibration; highest gain stage; horizontal sampling interval; individual CCD pixel; initial DNB on-orbit calibration; lowest gain stage; monthly sensor special operation; nighttime airglow; nighttime image; offline analysis; offline calibration approach; orbit daytime side; orbit nighttime side; radiance range imagery; science data loss; sensor on-orbit operation; special operation; ten digital number biased; three-gain-stage backside-illuminated charge-coupled device; visible imaging band design; Calibration; Charge coupled devices; Detectors; Earth; Moon; Orbits; Radiometry; Calibration; Visible Infrared Imaging Radiometer Suite (VIIRS); day–night band (DNB); day???night band (DNB); nighttime; optical sensor; satellite;
Journal_Title :
Geoscience and Remote Sensing, IEEE Transactions on
DOI :
10.1109/TGRS.2014.2321835