Facilities > VLA > Observing > RFI > RFI at S-Band (2-4 GHz)

RFI at S-Band (2-4 GHz)

by Emmanuel Momjian last modified May 12, 2018
Frequency (MHz)DescriptionOriginClassificationSpectrum
2178.0-2195.0 ?? Intermittent plot
2106.4 High alt baloon NM, FT Sunmer Intermittent plot
2204.5 Test telemetry NM, FT Bliss Intermittent plot
2180-2290 Satellite downlink OHD?GSO/MEO Continuous plot
2227.5-2231.5 ?? NM, WSMR? Intermittent plot
2246.5-2252.5 ?? NM, WSMR? Intermittent plot
2268.5-2274.5 ?? NM, WSMR? Intermittent
2282.5-2288.5 ?? NM, WSMR? Intermittent
2314.5-2320.5 ?? NM, WSMR? Intermittent
2320.0-2332.5 Sirius DARS OHD/GSO-Tundra Continous plot
2324.5-2330.5 ?? NM, WSMR? Intermittent
2332.5-2345.0 XM DARS OHD/GSO-Equatoral Continuous plot
2334.5-2340.5 ?? NM, WSMR? Intermittent
2387.5 High alt baloon NM, FT Sunmer Intermittent
2400.0-2483.5 Microwave Ovens Everywhere Intermittent plot
2400.0-2483.5 WiFi(802.11b) Wireless Everywhere Intermittent plot
2411.0-2413.0 Hughes Net WiFi Ranch houses Continuous
2483.5-2500.0 GlobalStar downlink Everywhere Continuous
2741 ABQ NEXRAD1 ABQ Intermittent
2791 ABQ NEXRAD1 ABQ Intermittent
3700.0-4200.0 Satellite downlinks OHD Continuous plot1, plot2, plot3


The Sirius digital radio system (and probably the satellites in the 2178 -- 2195 MHz band) comprises three satellites in a 24-hour, high eccentricity orbit with the apogee above the central U.S. For the Sirius system, the orbit is arranged such that each of the three satellites spends about eight hours near an azimuth of 25 degrees and an elevation of 65 degrees. The corresponding region in astronomical coordinates is between declinations 50 to 65 degrees, and hour angles between -1 and -2 hours. Observations at S-band within that area may -- or may not -- be seriously affected. The most reliable way to judge the seriousness of the satellite emissions is to inspect the switched power table data, particularly in those subbands where there is little RFI.