M11 Saturation Assessment Chris Elvidge Earth Observation Group NOAA-NESDIS-NGDC June 3, 2014

CCR Request for M11 collection at night The VIIRS Nightfire (VNF) product relies on the detects and analyzes temperature, source size and heat release of combustion sources at night, with heavy reliance on M10 data collected at night. Adding M11 would resolve many ambiguous detections with weak signal and would aid in noise screening. To constrain data volume, M7 collection at night would be discontinued. The CCR has approval for further study.

How did VIIRS come to collect daytime data at night? Original Message Subject: Re: [NOTIFY] Does anyone use M7 nighttime data? Date: Mon, 10 Feb :57: From: Shawn W Miller To: Chris Elvidge Hi Chris, Way back in , I was the one who led the push to have the instrument folks turn these bands on at night, precisely to help with Active Fires (since we were unsuccessful in getting the saturation temperature raised as high as we wanted it in the thermal IR). During that analysis I determined that M11 would saturate for most fires that consumed more than 1% of the area of a pixel - that's the main reason the program doesn't currently have it turned on at night. That's not to say my analysis didn't have errors, or that it still wouldn't provide the value you're looking for, but just a heads-up that you might want to look at the dynamic range of that band if you haven't already. Shawn _________________________________________ Shawn W. Miller, Ph.D. Chief Architect, JPSS CGS Engineering Fellow, Raytheon IIS Office: Cell:

Determination of M11 Detection Limit and Saturation Radiance Detection limit set at the background noise average plus four standard deviations in nighttime M11 data collected in polar region W/m2.sr.um. Saturation radiance found in daytime data collected of extreme events W/m2.sr.um.

M11 Detection Limit and Saturation

M11 Saturation on May 20, 2014 Alaska Fire

M11 Saturation Summary M11 will saturate on small numbers of extreme events. Full saturation will be obvious. Inclusion of subpixel saturation in VNF Planck curve fitting would introduce errors in temperature, source size and heat release retrievals. Subpixel saturation also happens for M12. VNF detects M12 saturation based on the M13/M12 ratio. A similar approach would be implemented for detecting subpixel saturation in M11.