Results of Ambient RF Environment and Noise Floor
Results of Ambient RF Environment and Noise Floor Measurements Taken in The U. S. In 2004 and 2005 Presented By: Robert Leck NOAA’s National Weather Service (QSS Group Inc. ) March 2006 National Weather Service 1
Overview NOAA operates a wide variety of sensitive systems. l Increased noise floor levels can negatively impact the operation of these systems. l Base lining the current noise floor levels will provide a basis for future comparative measurements. l National Weather Service 2
Ambient RF Environment Measurement System (ARFEMS) Objectives l Profile the ambient noise floor within frequency bands of interest to NOAA. l Establish an archived database. l Establish a basis for future comparative measurements. l Collect data that can be used for additional interference studies. National Weather Service 3
Frequency Bands of Interest 136 - 138 MHz 7. 45 - 7. 83 GHz 162 - 174 MHz 8. 025 - 8. 375 GHz 400 - 420 MHz 9. 3 - 9. 5 GHz 440 - 460 MHz 10. 6 - 11. 3 GHz 1. 54 - 1. 545 GHz 17. 6 - 18. 0 GHz 1. 67 - 1. 70 GHz 18. 0 - 18. 5 GHz 2. 0 - 2. 3 GHz 23. 6 - 24. 1 GHz 2. 7 - 3. 0 GHz 26. 5 - 28 GHz 5. 6 - 5. 65 GHz 31. 3 - 31. 5 GHz 6. 4 GHz - 6. 8 GHz 35. 9 - 37. 1 GHz National Weather Service 4
Site Locations National Weather Service 5
Site Locations Wallops Island, VA Albany, NY National Weather Service San Diego, CA Phoenix, AZ 6
System Overview Horn Antennas Frequency Range 1 Spectrum Analyzer Bandpass Filter Coaxial Switch LNA Frequency Range 2 Bandpass Filter RF Input LNA Ethernet Frequency Range N Above 26 GHz Frequency Range X Direct To Spectrum Analyzer Bandpass Filter LNA Harmonic Mixer Hub Frequency Range Y Remote Spectrum Analyzer Monitor Direct To Spectrum Analyzer Bandpass Filter LNA Harmonic Mixer Laptop w/Lab View Ethernet GPIB/Ethernet Converter RS-232 Ethernet Frequency Range N Temperature Sensor Variable Azimuth Drive Remote Video Camera Laptop For Remote Video Camera National Weather Service 7
System Overview National Weather Service 8
Measurement Methodology l. A spectrum analyzer was the primary measurement device. l Horizontal and vertical polarization profiles were captured over a 360 degree range of azimuths. l The ambient RF environment was profiled while characterizing the noise floor. National Weather Service 9
Data Analysis Methodology Data Reduction The Ambient Noise Floor was derived from post processing of Spectrum Analyzer measurements. l Data was processed to compensate for system gains and losses. l Interfering signals were removed from the ambient noise floor measurement. l All measurements were referenced to a measurement resolution bandwidth of 1 Hz. l National Weather Service 10
Data Analysis Methodology Data Reduction l In some cases the field measurements were equivalent to the measurement systems noise floor. l 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 11
Measurement Results (Horizontal Polarization) Ambient Noise Level (Horizontal Polarization) Urban Suburban Rural Airport 136 MHz-138 MHz 26. 25 GHz - 27. 0 GHz 25. 5 GHz-26. 25 GHz -130 -140 162 MHz-174 MHz 400 MHz-420 MHz -150 23. 6 GHz-24. 1 GHz 440 MHz-460 MHZ -160 -170 18. 5 GHz-19 GHz 1. 54 GHz-1. 545 MHz -180 -190 -200 18 GHz-18. 5 GHz 1. 670 GHz-1. 700 GHz 17. 6 GHz- 18 GHz 2 GHz-2. 3 GHz 10. 6 GHz-11. 3 GHz 2. 7 GHz-3. 0 GHz 9. 3 GHz-9. 5 GHz 5. 6 GHz-5. 650 GHz 8. 025 GHz-8. 375 GHz 6. 4 GHz-6. 8 GHZ 7. 45 GHz-7. 83 GHz National Weather Service 12
Measurement Results (Horizontal Polarization) Ambient Noise Level (Horizontal Polarization) Urban Suburban Rural Airport 136 MHz-138 MHz 26. 25 GHz - 27. 0 GHz 25. 5 GHz-26. 25 GHz -130 -140 162 MHz-174 MHz 400 MHz-420 MHz -150 23. 6 GHz-24. 1 GHz 440 MHz-460 MHZ -160 -170 18. 5 GHz-19 GHz 1. 54 GHz-1. 545 MHz -180 -190 -200 18 GHz-18. 5 GHz 1. 670 GHz-1. 700 GHz 17. 6 GHz- 18 GHz 2 GHz-2. 3 GHz 10. 6 GHz-11. 3 GHz 2. 7 GHz-3. 0 GHz 9. 3 GHz-9. 5 GHz 5. 6 GHz-5. 650 GHz 8. 025 GHz-8. 375 GHz 6. 4 GHz-6. 8 GHZ 7. 45 GHz-7. 83 GHz National Weather Service 13
Measurement Results (Horizontal Polarization) Ambient Noise Level (Horizontal Polarization) Urban Suburban Rural Airport 136 MHz-138 MHz 26. 25 GHz - 27. 0 GHz 25. 5 GHz-26. 25 GHz -130 -140 162 MHz-174 MHz 400 MHz-420 MHz -150 23. 6 GHz-24. 1 GHz 440 MHz-460 MHZ -160 -170 18. 5 GHz-19 GHz 1. 54 GHz-1. 545 MHz -180 -190 -200 18 GHz-18. 5 GHz 1. 670 GHz-1. 700 GHz 17. 6 GHz- 18 GHz 2 GHz-2. 3 GHz 10. 6 GHz-11. 3 GHz 2. 7 GHz-3. 0 GHz 9. 3 GHz-9. 5 GHz 5. 6 GHz-5. 650 GHz 8. 025 GHz-8. 375 GHz 6. 4 GHz-6. 8 GHZ 7. 45 GHz-7. 83 GHz National Weather Service 14
Measurement Results (Vertical Polarization) Ambient Noise Level (Vertical Polarization) Urban Suburban Rural Airport 136 MHz-138 MHz 26. 25 GHz - 27. 0 GHz 25. 5 GHz-26. 25 GHz -130 -140 162 MHz-174 MHz 400 MHz-420 MHz -150 23. 6 GHz-24. 1 GHz 440 MHz-460 MHZ -160 -170 18. 5 GHz-19 GHz 1. 54 GHz-1. 545 MHz -180 -190 -200 18 GHz-18. 5 GHz 1. 670 GHz-1. 700 GHz 17. 6 GHz- 18 GHz 2 GHz-2. 3 GHz 10. 6 GHz-11. 3 GHz 2. 7 GHz-3. 0 GHz 9. 3 GHz-9. 5 GHz 5. 6 GHz-5. 650 GHz 8. 025 GHz-8. 375 GHz 6. 4 GHz-6. 8 GHZ 7. 45 GHz-7. 83 GHz National Weather Service 15
Measurement Results (Vertical Polarization) Ambient Noise Level (Vertical Polarization) Urban Suburban Rural Airport 136 MHz-138 MHz 26. 25 GHz - 27. 0 GHz 25. 5 GHz-26. 25 GHz -130 -140 162 MHz-174 MHz 400 MHz-420 MHz -150 23. 6 GHz-24. 1 GHz 440 MHz-460 MHZ -160 -170 18. 5 GHz-19 GHz 1. 54 GHz-1. 545 MHz -180 -190 -200 18 GHz-18. 5 GHz 1. 670 GHz-1. 700 GHz 17. 6 GHz- 18 GHz 2 GHz-2. 3 GHz 10. 6 GHz-11. 3 GHz 2. 7 GHz-3. 0 GHz 9. 3 GHz-9. 5 GHz 5. 6 GHz-5. 650 GHz 8. 025 GHz-8. 375 GHz 6. 4 GHz-6. 8 GHZ 7. 45 GHz-7. 83 GHz National Weather Service 16
Measurement Results (Vertical Polarization) Ambient Noise Level (Vertical Polarization) Urban Suburban Rural Airport 136 MHz-138 MHz 26. 25 GHz - 27. 0 GHz 25. 5 GHz-26. 25 GHz -130 -140 162 MHz-174 MHz 400 MHz-420 MHz -150 23. 6 GHz-24. 1 GHz 440 MHz-460 MHZ -160 -170 18. 5 GHz-19 GHz 1. 54 GHz-1. 545 MHz -180 -190 -200 18 GHz-18. 5 GHz 1. 670 GHz-1. 700 GHz 17. 6 GHz- 18 GHz 2 GHz-2. 3 GHz 10. 6 GHz-11. 3 GHz 2. 7 GHz-3. 0 GHz 9. 3 GHz-9. 5 GHz 5. 6 GHz-5. 650 GHz 8. 025 GHz-8. 375 GHz 6. 4 GHz-6. 8 GHZ 7. 45 GHz-7. 83 GHz National Weather Service 17
Conclusions l The ambient noise floor was higher in frequency bands below 400 MHz. l At measurement frequencies of less than 2 GHz, 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 18
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. l 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. l National Weather Service 19
Conclusions l At frequencies within the 23. 6 GHz to 28 GHz bands a variation of 1 to 5 d. B was seen in the ambient noise floor measurements across urban, suburban, airport and remote environments for horizontally polarized measurements. National Weather Service 20
Conclusions l At frequencies within the 10. 6 GHz to 28 GHz bands a variation of 1 to 5 d. B was seen in the ambient noise floor measurements across urban, suburban, airport and remote environments for vertically polarized measurements. National Weather Service 21
Conclusions l Urban environments exhibited the highest level of ambient noise. l The data set provides a baseline for future comparative measurements. National Weather Service 22
Next Steps l Additional testing is planned for the 2006 -2007 time frame. l Testing will take place at sites that have been tested in the past. l Comparative analysis of the 2004 -2005 and the 2006 -2007 data will be made and summarized in an upcoming report. National Weather Service 23
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