SNPP VIIRS Modulated RSR Release 1.0
Ongoing spectral degradation in the SNPP VIIRS RTA mirror reflectance on-orbit (due to 
tungsten contaminant) is modulating the spectral response of SNPP VIIRS RSB RSR.  The spectral 
nature of the degradation is changing the relative contribution of out-of-band light to the 
total signal in all RSB as well as modifying the in-band spectral shape of most RSB.  So-called
"modulated RSR" have been generated using on-orbit F factors as surrogate for the RTA throughput
loss.  The F factors have been used by NASA VCST to tune a thin layer physical absorption model (V5) 
to match the on-orbit behavior.  The VCST model provides a throughput degradation spectrum, which
is convovled with the baseline RSR (NG Oct 2011 Band Average RSR) to produce modulated RSR.

The modulated RSR are a band average (i.e. over all detectors) RSR and represent a snapshot of VIIRS 
spectral performance for Feb 1, 2013 (orbit 6557).  About 75% of the expected 5 yr on-orbit RTA 
mirror darkening has taken place by Feb 1, 2013.  The remaining 25% degradation is expected to occur 
at ever-decreasing rates over the remainder of the 5 yr lifetime of SNPP VIIRS.

The modulated RSR have been used to populate the VIIRS SDR RSR LUT beginning April 5, 2013.

The file "rsr_degraded_orbit6557_v5B.tar" contains the following files:
33019 2013-02-19 21:03:31 rsr_degraded_orbit6557_I1_dispersion_v5.txt
33019 2013-02-19 21:03:31 rsr_degraded_orbit6557_I2_dispersion_v5.txt
33019 2013-02-19 21:03:31 rsr_degraded_orbit6557_I3_dispersion_v5.txt
33019 2013-02-19 21:03:31 rsr_degraded_orbit6557_M10_dispersion_v5.txt
33019 2013-02-19 21:03:31 rsr_degraded_orbit6557_M11_dispersion_v5.txt
33019 2013-02-19 21:03:31 rsr_degraded_orbit6557_M1_dispersion_v5.txt
33019 2013-02-19 21:03:31 rsr_degraded_orbit6557_M2_dispersion_v5.txt
33019 2013-02-19 21:03:31 rsr_degraded_orbit6557_M3_dispersion_v5.txt
33019 2013-02-19 21:03:31 rsr_degraded_orbit6557_M4_dispersion_v5.txt
33019 2013-02-19 21:03:31 rsr_degraded_orbit6557_M5_dispersion_v5.txt
33019 2013-02-19 21:03:31 rsr_degraded_orbit6557_M6_dispersion_v5.txt
33019 2013-02-19 21:03:31 rsr_degraded_orbit6557_M7_dispersion_v5.txt
33019 2013-02-19 21:03:31 rsr_degraded_orbit6557_M8_dispersion_v5.txt
33019 2013-02-19 21:03:31 rsr_degraded_orbit6557_M9_dispersion_v5.txt

These RSR files contain fields of wavelength (nanometers) and relative response (dimensionless).

Contacts:
Chris Moeller (U. Wisconsin); chrism@ssec.wisc.edu
Ning Lei (NASA VCST); ning.lei@sigmaspace.com

April 1, 2013