Frenchman Flat

The LSpec vicarious calibration site is situated on a homogeneous section of the Frenchman Flat dry lakebed found North-North-East of Mercury, Nevada on the Nevada Test Site (NTS) range. Center coordinates for the instrumented area are 115.93479 West longitude and 36.80928 North latitude. This playa is not unique for this application; vicarious calibration campaigns have been conducted over a variety of playa scattered throughout the Southwest. The Frenchman Flat playa surface is hard and clay-based. It has proven an ideal site with respect to surface homogeneity, restricted access (useful to eliminate vandalism), and infrastructure courtesy of the Non-Proliferation Testing and Evaluation Center (NPTEC). The NPTEC staff provides assistance with respect to site access and clearing, storage, communications, and the comforts of indoor office space. Data from the LSpec in-situ instruments are uploaded to the processing site at JPL. Communications are provided via a local cell tower.
In comparing this site to Railroad Valley, a commonly used playa, we note that Railroad Valley is an ideal site for sensors up to several kilometers in extent; Frenchman Flat supports sensors with footprints less than 300 m. The disadvantages of Railroad Valley are its remote location and lack of infrastructure, including access to a cell tower for the data upload. The surface contains more loose sand and salts and is therefore less stable. [1]

It is one of the CEOS LANDNET Sites. The site is managed by JPL/NASA; for more detailed information regarding the site, the point of contact is Carol J. Bruegge (

Instruments on the Test Site

  • LED Pods
  • ASD campaign radiometer
  • Meteorological observations


Climatological Data for Railroad Valley Playa

Parameter Mean Std Dev Min Max Max-Min (Max-Min)/Mean CV
Cloud Fraction (%)  0.2426 0.1447 0.0577 0.4682 0.4105 1.6922 0.5964
Water Vapour Content (g/cm2)  0.9927 0.4795 0.5240 1.9640 1.4400 1.4506 0.4831
Precipitation (mm/day)  0.3343 0.2334 0.0502 0.7723 0.7221 2.1597 0.6980
Ozone Content (Dobson)  322.4333 30.2985 285.5000 381.9000 96.4000 0.2990 0.0940



Temporal Variability of Cloud Fraction: on the X axis scale is one year (Jan-Dec); on the Y axis scale is the fraction 0-1
Temporal Variability of Water Vapour Content: X axis scale is one year (Jan-Dec); Y axis scale is 0-6 g/cm2
Temporal Variability of Precipitation. X axis scale is one year (Jan-Dec); Y axis scale is 0-10 mm/day
Temporal Variability of Ozone Content. X axis is one year (Jan-Dec); Y axis is 0-500 Dobson
Spectral Temporal Variability  



[1] LSpec Frenchman Spec - LSpec JPL/NASA




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