Presentation on theme: "National Weather Service 1 Results of Ambient RF Environment and Noise Floor Measurements Taken in The U.S. In 2004 and 2005 Presented By: Robert Leck."— Presentation transcript:
National Weather Service 1 Results of Ambient RF Environment and Noise Floor Measurements Taken in The U.S. In 2004 and 2005 Presented By: Robert Leck NOAAs National Weather Service (QSS Group Inc.) March 2006
National Weather Service 2 Overview NOAA operates a wide variety of sensitive systems. Increased noise floor levels can negatively impact the operation of these systems. Base lining the current noise floor levels will provide a basis for future comparative measurements.
National Weather Service 3 Ambient RF Environment Measurement System (ARFEMS) Objectives Profile the ambient noise floor within frequency bands of interest to NOAA. Establish an archived database. Establish a basis for future comparative measurements. Collect data that can be used for additional interference studies.
National Weather Service 6 Site Locations Wallops Island, VA San Diego, CA Albany, NYPhoenix, AZ
National Weather Service 7 System Overview Laptop For Remote Video Camera LNA Bandpass Filter LNA Bandpass Filter LNA Bandpass Filter Coaxial Switch Temperature Sensor Harmonic Mixer Direct To Spectrum Analyzer Direct To Spectrum Analyzer Above 26 GHz Horn Antennas Ethernet RF Input Frequency Range 2 Frequency Range N Frequency Range X Frequency Range Y Frequency Range N Laptop w/Lab View Spectrum Analyzer Remote Spectrum Analyzer Monitor GPIB/Ethernet Converter Ethernet Hub RS-232 Variable Azimuth Drive Remote Video Camera Ethernet Bandpass Filter Frequency Range 1
National Weather Service 9 Measurement Methodology A spectrum analyzer was the primary measurement device. Horizontal and vertical polarization profiles were captured over a 360- degree range of azimuths. The ambient RF environment was profiled while characterizing the noise floor.
National Weather Service 10 Data Analysis Methodology Data Reduction The Ambient Noise Floor was derived from post processing of Spectrum Analyzer measurements. Data was processed to compensate for system gains and losses. Interfering signals were removed from the ambient noise floor measurement. All measurements were referenced to a measurement resolution bandwidth of 1 Hz.
National Weather Service 11 Data Analysis Methodology Data Reduction In some cases the field measurements were equivalent to the measurement systems noise floor. In these cases the ambient noise floor was not detectable and was assumed to be below or closely equivalent to the system noise floor.
National Weather Service 18 Conclusions The ambient noise floor was higher in frequency bands below 400 MHz. At measurement frequencies of less than 2GHz, variations on the order of 1 to 5 db were seen in the ambient noise floor measurements across urban, suburban, rural and airport environments.
National Weather Service 19 Conclusions At frequencies within the 2 GHz to 23.6 GHz bands, the ambient noise floor was below the sensitivity of the measuring equipment for horizontally polarized measurements. At frequencies within the 2 GHz to 10.6 GHz bands, the ambient noise floor was below the sensitivity of the measuring equipment for vertically polarized measurements.
National Weather Service 20 Conclusions At frequencies within the 23.6 GHz to 28 GHz bands a variation of 1 to 5 dB was seen in the ambient noise floor measurements across urban, suburban, airport and remote environments for horizontally polarized measurements.
National Weather Service 21 Conclusions At frequencies within the 10.6 GHz to 28 GHz bands a variation of 1 to 5 dB was seen in the ambient noise floor measurements across urban, suburban, airport and remote environments for vertically polarized measurements.
National Weather Service 22 Conclusions Urban environments exhibited the highest level of ambient noise. The data set provides a baseline for future comparative measurements.
National Weather Service 23 Next Steps Additional testing is planned for the 2006-2007 time frame. Testing will take place at sites that have been tested in the past. Comparative analysis of the 2004-2005 and the 2006-2007 data will be made and summarized in an upcoming report.