Spectrum Engineering

The National Table of Frequency Allocations allocate the 2025-2110 MHz band to Federal space science services and the entire 1990-2110 MHz band to the non-Federal government fixed and mobile communication services. The Federal space science services provide the tracking, telemetry, and command (TT&C) functions for near-Earth and geostationary-satellite network operated by the National Aeronautics and Space Administration (NASA) and the National Oceanic and Atmospheric Administration (NOAA). The transmissions made to these satellites both from the surface of the Earth and from NASA’s Tracking and Data Relay Satellites (TDRS) in the 2025-2110 MHz band are essential to the success of the scientific and manned space programs.

The objectives of this report were to: 1) identify operational characteristics of representative Government radars operating in the 3.1-3.7 GHz frequency band, 2) outline a procedure for assessing the potential for EMI from these radars to adjacent-band FSS earth station receivers, and 3) identify methods for mitigating any received EMI.

The performance of the radios was evaluated using the SINAD histograms and by listening to the radio during the tests. Radios that had histograms which showed a distribution of SINAD measurements to higher values for a greater percentage of time performed better than those radios that had low SINAD values for higher percentages of time. Some radios performed better in Savannah than New Orleans.