SUOMI NPP VIIRS CALIBRATION/VALIDATION PROGRESS UPDATE

The successful launch of the Suomi National Partnership Program (SNPP) spacecraft on Oct. 28, 2011 with the Visible Infrared Imaging Radiometer Suite (VIIRS) starts a new generation of capabilities for operational environmental remote sensing for weather, climate, ocean, and other environmental applications. The VIIRS instrument was turned on 8th November, 2011 for the reflective solar bands. The VIIRS cryo-cooler door was opened on 18th January 2012, starting the observations with the thermal emissive bands.

VIIRS succeeds the NOAA AVHRR, NASA EOS MODIS, and DMSP OLS with 22 spectral bands covering wavelengths from 0.41 to 12.5 µm, providing data for the production of more than 20 Environmental Data Records (EDRs) with its calibrated and geolocated Sensor Data Record (SDRs). The VIIRS imagery EDR is the key performance parameter (KPP), while ocean color, sea surface temperature, green vegetation fraction, and polar winds are the next priority. Thanks to the wide swath (~3000 km), accurate geolocation of the VIIRS sensor data record, and frequent polar coverage, the VIIRS polar wind provides a unique product for weather forecasting.

This presentation will provide a progress update on the VIIRS postlaunch cal/val, and discuss issues resolved during the VIIRS calibration and verification process, in particular the degradation in the VIIRS rotating telescope assembly (RTA) mirrors. The RTA degradation is gradually leveling-off after reaching ~30%, and thus far has limited impact on instrument performance and products. Environmental data record users are generally satisfied with the data quality which meets the product requirements.

In the near future, major upgrade of the VIIRS SDR processing will include the automated radiometric calibration of the VIIRS reflective solar bands, and the operationalization of the DNB straylight correction. Other remaining issues include the calibration of the dual gain thermal emissive band M13 because there is no onboard calibration at low gain for this band. Bias between the VIIRS M15 and CrIS measurements over cold scenes also needs to be addressed. The VIIRS radiometric, spectral and geospatial performance as well as calibration parameters and event databases are actively maintained at http://ncc.nesdis.noaa.gov.

REFERENCES Cao, C., J. Xiong, F. DeLuccia, Q. Liu, S. Blonski, and D. Pogorzala, Visible/Infrared Imager Radiometer Suite (VIIRS) Sensor Data Record (SDR), User's Guide, version 1, 2011.

Cao, C., F. Deluccia, X. Xiong, R. Wolfe, and F. Weng, 2013a, Early On-orbit Performance of the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-orbiting Partnership (Suomi-NPP) Satellite, IEEE Transaction on Geoscience and Remote Sensing, DOI:10.1109/TGRS.2013.2247768.

Cao, C., X. Shao, S. Uprety, 2013b, Detecting Light Outages After Severe Storems Using the Suomi-NPP/VIIRS Day/Night Band Radiances, IEEE Geoscience and Remote Sensing Letters, DOI: 10.1109/LGRS.2013.2262258.

DeLuccia, F. et al., 2013, Automated Calibration of the NPP VIIRS Reflective Solar Bands (JGR special issue).

Liao, L., S. Weiss, S. Mills, and Bruce Hauss, 2013, Suomi NPP VIIRS Day-Night-Band (DNB) On-Orbit Performance (JGR special issue).

Liu, Q., C. Cao, and F. Weng, 2013: Assessment of Suomi National Polar-Orbiting Partnership VIIRS Emissive Band Calibration and Inter-Sensor Comparisons, IEEE JSTAR, 6, 1737-1748, 10.1109/JSTARS.2013.2263197.

Sun, N., M. Grotenhuis , T. Chang , X. Jin , Q. Liu , Y. Chen , 2013, Instrument Performance and Sensor Data Accuracy Long-Term Monitoring for Suomi-NPP and JPSS (JGR special issue).

Wolfe, R. et al., 2013, VIIRS Geospatial Performance (JGR special issue).

Xiong, X. et al., 2013, VIIRS Onboard Calibration and Instrument Performance (JGR special issue).