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Author (up) Ban, Y.; Cao, C.; Shao, X.
Title Assessment of scan-angle dependent radiometric bias of Suomi-NPP VIIRS day/night band from night light point source observations Type Journal Article
Year 2015 Publication Proc. SPIE 9607, Earth Observing Systems XX, 2015 Abbreviated Journal
Volume Issue Pages 960727
Keywords Remote sensing; Suomi NPP; VIIRS DNB; calibration
Abstract The low gain stage of VIIRS Day/Night Band (DNB) on Suomi-NPP is calibrated using onboard solar diffuser. The calibration is then transferred to the high gain stage of DNB based on the gain ratio determined from data collected along solar terminator region. The calibration transfer causes increase of uncertainties and affects the accuracy of the low light radiances observed by DNB at night. Since there are 32 aggregation zones from nadir to the edge of the scan and each zone has its own calibration, the calibration versus scan angle of DNB needs to be independently assessed. This study presents preliminary analysis of the scan-angle dependence of the light intensity from bridge lights, oil platforms, power plants, and flares observed by VIIRS DNB since 2014. Effects of atmospheric path length associated with scan angle are analyzed. In addition, other effects such as light changes at the time of observation are also discussed. The methodology developed will be especially useful for JPSS J1 VIIRS due to the nonlinearity effects at high scan angles, and the modification of geolocation software code for different aggregation modes. It is known that J1 VIIRS DNB has large nonlinearity across aggregation zones, and requires new aggregation modes, as well as more comprehensive validation.
Address Univ. of Maryland, College Park, USA
Corporate Author Thesis
Publisher SPIE Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 1259
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Author (up) Cao, C.; Zong, Y.; Bai, Y.; Shao, X.
Title Preliminary study for improving the VIIRS DNB low light calibration accuracy with ground based active light source Type Journal Article
Year 2015 Publication Proc. SPIE 9607, Earth Observing Systems XX, 2015 Abbreviated Journal
Volume Issue Pages 96070D
Keywords Remote sensing; Suomi NPP; VIIRS DNB; calibration
Abstract There is a growing interest in the science and user community in the Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) low light detection capabilities at night for quantitative applications such as airglow, geophysical retrievals under lunar illumination, light power estimation, search and rescue, energy use, urban expansion and other human activities. Given the growing interest in the use of the DNB data, a pressing need arises for improving the calibration stability and absolute accuracy of the DNB at low radiances. Currently the low light calibration accuracy was estimated at a moderate 15%-100% while the long-term stability has yet to be characterized. This study investigates selected existing night light point sources from Suomi NPP DNB observations and evaluates the feasibility of SI traceable nightlight source at radiance levels near 3 nW·cm−2·sr−1, that potentially can be installed at selected sites for VIIRS DNB calibration/validation. The illumination geometry, surrounding environment, as well as atmospheric effects are also discussed. The uncertainties of the ground based light source are estimated. This study will contribute to the understanding of how the Earth’s atmosphere and surface variability contribute to the stability of the DNB measured radiances, and how to separate them from instrument calibration stability. It presents the need for SI traceable active light sources to monitor the calibration stability, radiometric and geolocation accuracy, and point spread functions of the DNB. Finally, it is also hoped to address whether or not active light sources can be used for detecting environmental changes, such as aerosols.
Address NESDIS/STAR, National Oceanic and Atmospheric Administration, USA
Corporate Author Thesis
Publisher SPIE Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 1261
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Author (up) Fulbright, J.P.; Xiong, X.
Title Suomi-NPP VIIRS day/night band calibration with stars Type Journal Article
Year 2015 Publication Proc. SPIE 9607, Earth Observing Systems XX, 2015 Abbreviated Journal
Volume Issue Pages 96071S
Keywords Remote Sensing; Suomi NPP; VIIRS DNB; calibration
Abstract Observations of stars can be used to calibrate the radiometric performance of the Day/Night Band (DNB) of the Suomi-NPP instrument VIIRS. Bright stars are normally visible in the Space View window. In this paper, we describe several potential applications of stellar observations with preliminary results for several. These applications include routine trending of the gain of the highand mid-gain stages of the DNB and trending the gain ratio between those stages. Many of the stars observed by the VIIRS DNB have absolute flux curves available, allowing for an absolute calibration. Additionally, stars are visible during scheduled lunar roll observations. The electronic sector rotations applied during the scheduled lunar observations greatly increases the sky area recorded for a brief period, increasing the observing opportunities. Additionally, the DNB recorded data during the spacecraft pitch maneuver. This means the deep sky was viewed through the full Earth View. In this situation, thousands of stars (and the planet Mars) are recorded over a very short time period and over all aggregation zones. A possible application would be to create a gain curve by comparing the instrument response to the known apparent stellar brightness for a large number of stars of similar spectral shape. Finally, the DNB is especially affected the mirror degradation afflicting VIIRS. The degradation has shifted peak of the relative spectral response (RSR) of the DNB the blue and the effective band pass has been slightly reduced. The change in response for hot stars (effective temperatures of over 30,000 K) due to this degradation will differ by about 10 percent from the response change of cool stars (below 3500 K).
Address Science Systems and Applications, Inc., USA
Corporate Author Thesis
Publisher SPIE Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 1260
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Author (up) Lee, S.; Wang, W.; Cao, C.
Title JPSS-1 VIIRS DNB nonlinearity and its impact on SDR calibration Type Journal Article
Year 2015 Publication Proc. SPIE 9607, Earth Observing Systems XX, 2015 Abbreviated Journal
Volume Issue Pages 960717
Keywords Remote sensing; Suomi NPP; VIIRS DNB; JPSS-1; calibration
Abstract During JPSS-1 VIIRS testing at Raytheon El Segundo, a larger than expected radiometric response nonlinearity was discovered in Day-Nigh Band (DNB). In addition, the DNB nonlinearity is aggregation mode dependent, where the most severe non-linear behavior are the aggregation modes used at high scan angles (<~50 degree). The DNB aggregation strategy was subsequently modified to remove modes with the most significant non-linearity. We characterized the DNB radiometric response using pre-launch tests with the modified aggregation strategy. The test data show the DNB non-linearity varies at each gain stages, detectors and aggregation modes. The non-linearity is most significant in the Low Gain Stage (LGS) and could vary from sample-to-sample. The non-linearity is also more significant in EV than in calibration view samples. The HGS nonlinearity is difficult to quantify due to the higher uncertainty in determining source radiance. Since the radiometric response non-linearity is most significant at low dn ranges, it presents challenge in DNB cross-stage calibration, an critical path to calibration DNB’s High Gain Stage (HGS) for nighttime imagery. Based on the radiometric characterization, we estimated the DNB on-orbit calibration accuracy and compared the expected DNB calibration accuracy using operational calibration approaches. The analysis showed the non-linearity will result in cross-stage gain ratio bias, and have the most significant impact on HGS. The HGS calibration accuracy can be improved when either SD data or only the more linearly behaved EV pixels are used in cross-stage calibration. Due to constrain in test data, we were not able to achieve a satisfactory accuracy and uniformity for the JPSS-1 DNB nighttime imagery quality. The JPSS-1 DNB nonlinearity is a challenging calibration issue which will likely require special attention after JPSS-1 launch.
Address NOAA National Environmental Satellite, Data, and Information Service, USA
Corporate Author Thesis
Publisher SPIE Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 1262
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