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

1National Weather Service

Results of Ambient RF Results of Ambient RF Environment and Noise Floor Environment and Noise Floor

Measurements Taken in The U.S. Measurements Taken in The U.S. In 2004 and 2005In 2004 and 2005

Presented By:

Robert Leck

NOAA’s National Weather Service(QSS Group Inc.)

March 2006


OverviewOverview 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.


Ambient RF Environment Ambient RF Environment Measurement System (ARFEMS) Measurement System (ARFEMS)

ObjectivesObjectivesProfile 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.


Frequency Bands of InterestFrequency 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


Site LocationsSite Locations


Site LocationsSite Locations

Wallops Island, VA San Diego, CA

Albany, NY Phoenix, AZ


System OverviewSystem Overview

Laptop For Remote Video Camera

LNA

LNABandpass Filter

LNABandpass Filter

LNABandpass Filter

CoaxialSwitch

Temperature Sensor

Harmonic Mixer

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/EthernetConverter

Ethernet

Ethernet

Hub

RS-232Variable

Azimuth Drive

RemoteVideo Camera

Ethernet

Bandpass Filter

Frequency Range 1


System OverviewSystem Overview


Measurement MethodologyMeasurement 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.


Data Analysis MethodologyData Analysis MethodologyData ReductionData 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.


Data Analysis MethodologyData Analysis MethodologyData ReductionData 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.


Measurement Results Measurement Results (Horizontal Polarization)(Horizontal Polarization)

Ambient Noise Level(Horizontal Polarization)

-200

-190

-180

-170

-160

-150

-140

-130136 MHz-138 MHz

162 MHz-174 MHz

400 MHz-420 MHz

440 MHz-460 MHZ

1.54 GHz-1.545 MHz

1.670 GHz-1.700 GHz

2 GHz-2.3 GHz

2.7 GHz-3.0 GHz

5.6 GHz-5.650 GHz

6.4 GHz-6.8 GHZ

7.45 GHz-7.83 GHz

8.025 GHz-8.375 GHz

9.3 GHz-9.5 GHz

10.6 GHz-11.3 GHz

17.6GHz- 18 GHz

18 GHz-18.5 GHz

18.5 GHz-19 GHz

23.6 GHz-24.1 GHz

25.5 GHz-26.25 GHz

26.25 GHz - 27.0 GHz

Urban Suburban Rural Airport




-200

-190

-180

-170

-160

-150

-140

-130136 MHz-138 MHz

162 MHz-174 MHz

400 MHz-420 MHz

440 MHz-460 MHZ

1.54 GHz-1.545 MHz

1.670 GHz-1.700 GHz

2 GHz-2.3 GHz

2.7 GHz-3.0 GHz

5.6 GHz-5.650 GHz

6.4 GHz-6.8 GHZ

7.45 GHz-7.83 GHz

8.025 GHz-8.375 GHz

9.3 GHz-9.5 GHz

10.6 GHz-11.3 GHz

17.6GHz- 18 GHz

18 GHz-18.5 GHz

18.5 GHz-19 GHz

23.6 GHz-24.1 GHz

25.5 GHz-26.25 GHz

26.25 GHz - 27.0 GHz





-200

-190

-180

-170

-160

-150

-140

-130136 MHz-138 MHz

162 MHz-174 MHz

400 MHz-420 MHz

440 MHz-460 MHZ

1.54 GHz-1.545 MHz

1.670 GHz-1.700 GHz

2 GHz-2.3 GHz

2.7 GHz-3.0 GHz

5.6 GHz-5.650 GHz

6.4 GHz-6.8 GHZ

7.45 GHz-7.83 GHz

8.025 GHz-8.375 GHz

9.3 GHz-9.5 GHz

10.6 GHz-11.3 GHz

17.6GHz- 18 GHz

18 GHz-18.5 GHz

18.5 GHz-19 GHz

23.6 GHz-24.1 GHz

25.5 GHz-26.25 GHz

26.25 GHz - 27.0 GHz



Measurement Results Measurement Results (Vertical Polarization)(Vertical Polarization)

Ambient Noise Level(Vertical Polarization)

-200

-190

-180

-170

-160

-150

-140

-130136 MHz-138 MHz

162 MHz-174 MHz

400 MHz-420 MHz

440 MHz-460 MHZ

1.54 GHz-1.545 MHz

1.670 GHz-1.700 GHz

2 GHz-2.3 GHz

2.7 GHz-3.0 GHz

5.6 GHz-5.650 GHz

6.4 GHz-6.8 GHZ

7.45 GHz-7.83 GHz

8.025 GHz-8.375 GHz

9.3 GHz-9.5 GHz

10.6 GHz-11.3 GHz

17.6GHz- 18 GHz

18 GHz-18.5 GHz

18.5 GHz-19 GHz

23.6 GHz-24.1 GHz

25.5 GHz-26.25 GHz

26.25 GHz - 27.0 GHz





-200

-190

-180

-170

-160

-150

-140

-130136 MHz-138 MHz

162 MHz-174 MHz

400 MHz-420 MHz

440 MHz-460 MHZ

1.54 GHz-1.545 MHz

1.670 GHz-1.700 GHz

2 GHz-2.3 GHz

2.7 GHz-3.0 GHz

5.6 GHz-5.650 GHz

6.4 GHz-6.8 GHZ

7.45 GHz-7.83 GHz

8.025 GHz-8.375 GHz

9.3 GHz-9.5 GHz

10.6 GHz-11.3 GHz

17.6GHz- 18 GHz

18 GHz-18.5 GHz

18.5 GHz-19 GHz

23.6 GHz-24.1 GHz

25.5 GHz-26.25 GHz

26.25 GHz - 27.0 GHz





-200

-190

-180

-170

-160

-150

-140

-130136 MHz-138 MHz

162 MHz-174 MHz

400 MHz-420 MHz

440 MHz-460 MHZ

1.54 GHz-1.545 MHz

1.670 GHz-1.700 GHz

2 GHz-2.3 GHz

2.7 GHz-3.0 GHz

5.6 GHz-5.650 GHz

6.4 GHz-6.8 GHZ

7.45 GHz-7.83 GHz

8.025 GHz-8.375 GHz

9.3 GHz-9.5 GHz

10.6 GHz-11.3 GHz

17.6GHz- 18 GHz

18 GHz-18.5 GHz

18.5 GHz-19 GHz

23.6 GHz-24.1 GHz

25.5 GHz-26.25 GHz

26.25 GHz - 27.0 GHz



ConclusionsConclusions

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.



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.



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.



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.



Urban environments exhibited the highest level of ambient noise.

The data set provides a baseline for future comparative measurements.


Next StepsNext 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.

Documents

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