Atmospheric channel characterization for ORCA testing at NTTR

The DARPA Optical RF Communications Adjunct (ORCA) program was created to bring high data rate networking to the warfighter via airborne platforms. Recent testing of the ORCA system was conducted by the Northrop Grumman Corporation (NGC) at the Nevada Test and Training Range (NTTR) at the Nellis Air Force Range near Tonopah, NV. The University of Central Florida (UCF) conducted a parallel test to measure path-averaged values of the refractiveindex structure parameter, the inner scale of turbulence, and the outer scale of turbulence along the ORCA propagation path from an airborne platform to the ground at Antelope Peak. In addition, weather instrumentation was set up at ground level on Antelope Peak to measure local conditions on the mountain top. This paper presents background information on expected atmospheric conditions for the channel, models that were used by UCF for the measurements, path-averaged values of the three atmospheric parameters, and a Cn2 profile model as a function of altitude.