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National Calibration Center home page National Oceanographic & Atmospheric Administration website NOAA Center for Satellite Applications and Research website

Global 20+ Site Validation System (G20)

Although VIIRS has onboard calibration for all channels, it is important that the calibrated SDR are independently validated. A major effort towards this end is the development of the world-wide validation site radiometric time series. The goal is to construct the time series for the entire period of the mission over about 20 vicarious sites to monitor the stability of the VIIRS calibration. Many of these sites are endorsed by the Committee on Earth Observation Satellites (CEOS) Working Group on Calibration/Validation (WGCV). Legacy sites such as MOBY are also included. The time series has already been used for diagnoses for the recent H and F factor trend changes. In addition to the ground based sites, the time series also includes the Deep Convective Cloud time series, and the Lunar Band Ratio Time Series.

Instruction: Use mouse wheel to zoom in and out; Hold left mouse button and drag to rotate; Click on a site for details.

For Regional Validation Site, click here.

Symbol Cal/Val Site Lat
Symbol Cal/Val Site Lat
RailroadValley (CEOS Instrumented site) 38.504 -115.692 DCC (Deep convective cloud time series) 0 -130
LaCrau (CEOS Instrumented site) 43.559 4.864 ARM-ENA (ARM East Atlantic) 39.09 -28.03
Gobabeb (CEOS Instrumented site) -23.600 15.12 ARM-SGP (ARM Southern Great Plain) 36.607 -97.488
Baotou (CEOS Instrumented site) 40.851 109.628 ARM-NSA (ARM North Slope Alaska) 71.323 -156.609
Holly (Geolocation time series site) 34.39 -119.906 SonoranDesert (Peudo desert site) 32 -114.4
MOBYHawaii (Ocean/Water site) 20.817 -157.192 DunhuangDesert (Peudo desert site) 40.18 94.27
BajaGulf (Ocean/Water site) 26.15 -110.20 SimpsonAustralia (Peudo desert site) -24.225 137.789
BajaOcean (Ocean/Water site) 28.30 -114.63 TingaTinganaAustralia (Peudo desert site) -29.0 139.86
LaPaz (Ocean/Water site) 24.1 -110.3 AmburlaAustralia (Peudo desert site) -23.39 133.12
LakeTahoe (Ocean/Water site) 39.099 -120.033
QingahiLake (Ocean/Water site) 36.93 100.137
FloridaBay (Ocean/Water site) 25.33 -81.76 DomeC (Snow/Ice site) -75.1 123.390
TampaBay (Ocean/Water site) 27.78 -82.53 MtEverest (Snow/Ice site) 28.042 86.922
Libyan1 (Desert site) 24.42 13.35 Purog (Snow/Ice site) 33.90 89.15
Libyan4 (Desert site) 28.55 23.4 Muztag (Snow/Ice site) 87.43 36.38
Mali1 (Desert site) 19.12 -4.85 Jingang (Snow/Ice site) 89.73 35.61
Mauritania1 (Desert site) 19.4 -9.3 Toze (Snow/Ice site) 82.35 34.77
Mauritania2 (Desert site) 20.85 -8.78 Kunlun (Snow/Ice site) 81 35.34
Egypt1 (Desert site) 27.12 26.1
Sudan1 (Desert site) 21.74 28.22
Algeria5 (Desert site) 31.02 2.23
Algeria3 (Desert site) 30.32 7.66
Arabia2 (Desert site) 20.13 50.96