MROS RF_Survey_SoW.docx

Statement of Work (SOW) for Radiosonde Frequency Migration Project (RFMP) Radio Frequency Survey

DEPARTMENT OF COMMERCE

NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION

NATIONAL WEATHER SERVICE

OFFICE OF OBSERVATIONS

1325 EAST WEST HIGHWAY

SILVER SPRING, MD 20910

V 1.0

Contents

1 Introduction

1.1 Background

Since the late 1930's the NWS has measured vertical atmospheric profiles of pressure, temperature, relative humidity, and wind velocity. The NWS has primarily used balloon-borne sensors for atmospheric observations, as well as meteorological satellites, radar, wind-profilers, and aircraft observations. Atmospheric observations are a key source of data for weather forecasts and related products including severe weather watches and warnings and climate forecasts.

‘Upper air’ is defined as the region above the surface of the earth to a height of 110,000 feet into the atmosphere. ‘Upper air measurement’ is the measurement of atmospheric conditions including temperature, humidity, wind velocity and barometric pressure within this region. Upper air measurements are usually accomplished using a measurement device known as a ‘radiosonde’, flown by a balloon ascending through the atmosphere and following the wind direction. Balloons with radiosondes are flown at least twice a day at 00 UTC and 12 UTC, as well as at ad-hoc launches during or before severe weather. The information captured is transmitted by radio waves from the radiosonde to the ground and then is transmitted to computer modeling and forecasting systems to develop watches, warnings and forecasts both at NWS weather forecast offices and NWS national centers.

Figure 11 The NWS Upper Air radiosonde process As part of a presidential initiative to repurpose Federal radio spectrum for non-federal use, the radio spectrum NOAA uses to operate Polar-orbiting Operational Environmental Satellites (POES), between 1695 MHz and 1710 MHz has been reallocated for shared use by commercial wireless communications service providers. This shift has created an overlap with frequencies currently used by radiosondes and Geostationary Operational Environmental Satellites, operating in the 1675 and 1695 MHz band. The NWS has chosen to replace the existing radiosonde observations network operating on frequency channels between 1675 and 1683 MHz with a new network using the 400.15 – 406 MHz frequency band to avoid causing interference with meteorological satellites downlinks. See Appendix B, U.S. Frequency Allocations, for more information.

1.2 Objectives

The objective of this contract/task order is to complete a radio frequency (RF) survey of the RF environment in and around the 403 MHz band, at the locations listed in Appendix A, and document the electromagnetic environment in the 403 MHz band and the adjacent bands and the risks for access to the 403 MHz band by the radiosonde observing system.

2 Statement of Work

2.1 Scope of Work

This Statement of Work (SOW) describes the Radio-frequency (RF) survey and analysis to be performed by the Contractor.

The Project will consist of a kickoff conference followed by the conduct of 64 individual surveys at NWS upper-air sites in the Continental United States (CONUS). These locations are listed in Appendix A, Survey Locations. The Contractor shall execute surveys following a timeline developed in coordination with the NWS and meet NWS requirements for survey execution and data production, specified herein. The Contractor shall provide bi-weekly updates on the status of the survey's execution and deliver monthly RF survey reports.

The Contractor shall determine and arrange all necessary site survey travel and local support services to conduct the RF surveys. Additionally the Contractor shall make all necessary arrangements with the local offices (sites) to determine agreed upon site visit dates, and any work logistical concerns.

The following figure shows a notional Manual Radiosonde Observing System (MROS) RF Survey schedule:

Figure 201 Notional MROS RF Survey Schedule

2.2 Contract kickoff conference

Within thirty days after award, the Contractor shall attend and support a contract kickoff conference held at the NWS Sterling Field Support Center in Sterling, VA. The objectives of the kickoff include:

· Provide the Contractor with background information on RF interference in radiosonde systems

· Present and discuss radiosonde observation system antenna siting guidelines

· Review reporting requirements and format

· Review and respond to Contractor questions

2.3 Survey Execution

The Contractor shall perform site surveys in accordance with the following four primary areas:

· Measure and document the RF environment at the site

· Investigate identified signals both in and near the 403 MHz band

· Provide in-band radiosonde system channeling recommendations

· Identify and propose an antenna installation location per the siting guidelines in appendix D for MROS 403 MHz band receive systems

2.3.1 Measurement and documentation of the RF environment

The Contractor shall perform an assessment and record the RF environment of the surrounding topology at the survey site, including:

· Identification of potential obstructions

· Identification of all RF signals that are potential sources of interference

· Photographs of the site and sufficient imagery and diagrams to thoroughly depict unique features and potential obstructions.

· A minimum period of 24 hours covering the most active RF period of the week as determined by the federal ask manager.

· Measure ,identify and record all RF activity between 350 – 450 MHz

· Perform detailed measurements and identify all signal activity between 400 – 406 MHz, including the noise floor and all in-band deviations from it

· RF surveying shall include measurements taken during synoptic times (0 and 12 UTC)

· Use of appropriate test equipment and settings, with sufficient sensitivity to obtain valid noise floor and potential interferer measurements

2.3.2 Investigation of identified signals

The Contractor shall capture detailed measurements of the identified interference. The Contractor shall assess transmission characteristics including power, frequency, bandwidth and signal waveform characteristics.

The Contractor shall reference federal licensing and authorization data for source determination and identification. If unable to determine and identify sources through federal data sources, the Contractor shall perform triangulation to identify the signal sources' operators and locations.

2.3.3 Developing in-band channeling recommendations

The Contractor shall develop and propose recommendations for MROS frequency channels based on the site survey's findings, in accordance with the channeling Guidelines in Appendix C and as follows:

· Identify and document frequencies in the 403 MHz band, of 200 KHz or greater width, with the least noise that should be prioritized for operational channel selection

· Identify frequencies in the 403 MHz band, of 200 KHz or greater width, where the noise floor is elevated but still usable for radiosonde operations

· Identify frequencies in the 403 MHz band, of 200 KHz or greater width, which should be avoided due to competing in-band RF activity

· If at least four individual, non-overlapping 200 kHz channels cannot be accommodated, identify the largest bandwidth for which four channels can be accommodated

· The operational channels must have a 200 KHz frequency guard, centered 100 KHz from each side.

2.3.4 Identification of antenna siting for future 403 MHz receive systems The Contractor shall conduct siting activities for the siting of 403 MHz radiosonde observation system in accordance with NWS RFMP guidance and guidelines provided in Appendix D and the following requirements antennas to:

· Identify two antenna installation locations, a primary location and a secondary location, with the lowest RF interference potential and within 200 feet of the signal processor

· Perform RF survey measurements from the identified primary and secondary siting locations

· Photograph the site and provide sufficient imagery and diagrams to thoroughly depict siting location for MROS antennas

2.4 Deliverables

Contractor shall submit for government review and approval the following deliverables:

· Pre-survey items including questions for kickoff conference, intended RF survey equipment, survey schedule, report templates and execution procedures

· RF survey reports for each survey executed, including: RF interference found to be present and an updated listing of completed RF surveys

· Bi-weekly project update meeting minutes All documents delivered by the Contractor shall be in electronic format using MS Office software applications including data in Excel and reports in Word format.

2.4.1 Pre-survey Items

The Contractor shall provide the following to the NWS no later than 20 days after award of contract:

· A list of pre-survey questions for NWS on project procedures and requirements

· A proposed list of equipment to be used for RF surveys

· A proposed RF survey report template

· A proposed site visit sequence and survey execution schedule

· A proposed survey execution procedure

2.4.2 RF Survey Reports

Each RF survey shall be documented in a RF survey report, and submitted to NWS within 2 weeks of completion of each survey. Each RF survey report submitted by Contractor shall be submitted for review and approval by the NWS for acceptance. Report deficiencies shall be corrected and resubmitted for approval within 2 weeks of receipt of review comments from NWS. The survey report shall contain:

· An assessment of the surrounding topology at the survey site including potential obstructions and incumbent transmitting signals that are potential sources of interference

· Site imagery and diagrams thoroughly depicting unique features and potential obstructions

· A record of the site RF environment for a minimum period of 24 hours during the most active RF period of the week including measurements during synoptic times (0 and 12 UTC)

· Documentation of all known competing 403MHz band activities.

· A general measurement and assessment of RF activity between 350-450MHz containing:

· Identification of problematic signals for radiosonde operations nearby the 403 MHz band

· Measurement of transmission characteristics including power, frequency, and signal profile for each potentially problematic signal

· Detailed assessment of RF activity between 400 – 406 MHz including the following measurements:

· Noise floor measurement

· Measurements of identified interference with transmission characteristics including power, frequency, and signal profile.

· Spectrum analyzer screen captures for 350 – 450 MHz, and 400 – 406 MHz

· Interference sources determination from Federal Frequency Commission (FCC) licensing lists, or, alternatively, sources determined by triangulation

· Areas of the 403 MHz band, of 200 KHz or greater width, with the least noise that should be prioritized for operational channel selection

· Areas of the 403 MHz band, of 200 KHz or greater width, where the noise floor is elevated but still usable for radiosonde operations

· Areas of the 403 MHz band, of 200 KHz or greater width, which should be avoided due to competing in-band RF activity

· Two identified antenna installation locations, a primary location and a secondary location, with the lowest RF interference potential

· RF survey measurements from the identified primary and secondary siting locations.

· Site imagery and diagrams thoroughly depicting and identifying the primary and secondary siting locations

· RF measurement files in comma separated value, Excel, or text formats including date and sequential time of measurements, GPS location, and measurements in dBm

2.4.3 Periodic Project Updates

The Contractor shall provide bi-weekly updates on the planning, coordination and scheduling of survey execution and delivery of RF survey reports. Updates shall be delivered as reports to the NWS and via conferences with NWS, in person or via video or teleconferencing, by the Contractor's project manager with support by subject matter expert. The Contractor shall provide conference meeting minutes, including issues raised and action items, to the NWS within three business days of each update.

2.4.4 RF Interference Notifications

Within 48 hours after completion of each RF survey, the Contractor shall provide the NWS with a summary report of RF interference detected in the 403MHz band at the survey site. The notification shall include graphical plots of undesired interference frequency and power level including spectrum analyzer plots for the frequency ranges between 350 – 450 MHz, and 400 – 406 MHz, as well as information on possible interference sources.

2.4.5 RF Survey Completion Report

The Contractor shall provide a report within 30 days of the final site survey. The completion report shall include summary results from each survey and a project summary. The report shall be delivered electronically in MS Word and Excel format.

Appendix A - Survey Locations

Appendix B - U.S. Frequency Allocations

Appendix C - Channeling Guidelines The following represents an example of a channeling procedure:

RF sweep from 400-406 MHz

Figure E01: Detected frequencies in 400-406 MHz band

Identification of major spikes

Table E-1: Avoid Frequency list

Develop the channel recommendation

Develop a recommendation for the 403 MHz band showing good, useable and to-avoid regions:

Figure E02: Recommended operational channels

Appendix D - Antenna Siting Guidelines

The Contractor will use engineering best practices for the placement of an antenna and will work with the NWS RFMP program office and on-site WFO location technicians to determine the optimal position of the antennas when conducting the RF survey.

The following antenna siting guidelines should be followed:

· Maximum cable run length of 200 ft. from the receiver installation point within the WFO

· Antenna installation options, in order of preference, include:

1- WFO rooftop 2- UAIB rooftop 3- Existing towers 4- New tower

· Avoid installing the receive antenna in front of any existing directional antenna main lobe. The safe distance will depend on the antenna shape, transmitted power, gain and line of sight.

· The recommended installation location should be on the null zone of the existing directional antenna.

· Choose an antenna location that has a clear view of the sky down to the horizon in all directions if possible.

· Higher elevation areas such as rooftops are beneficial for staying clear of obstructions.

· The antenna should be installed so that it is not screened by large obstacles, such as buildings, thick forest, or high metal masts.

· Avoid installing on metal roofs and other corresponding large surfaces. Metal structures reflect signals in some instances, causing multipath interference.

Technical Exhibit 1: Suggested RF Survey Report Template

Radio Frequency Survey Report for Upper Air Site Name – City, State (NWS /OPPSD)

Version X.X Prepared By : XXXXXX Date : MO/Day/Year

U.S. DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration/ National Weather Service/Office of Observations Surface and Upper Air Division/Evaluation Branch

Overview An RF survey was conducted for XXXX in City, State. This survey was conducted to assess the RF environment and determine the active frequencies around the site XXXXX.

Based on the survey findings:

A recommended frequency chart was developed to identify the operational, avoid and use with caution 403 MHz frequencies. The optimal receive antennas locations were suggested.

The National Weather Service Personnel/representative is/are:

Name Telephone Email

All Specific site address and information:

Address:

Contents

1 Executive Summary The National Oceanographic and Atmospheric Administration (NOAA) Radiosonde Frequency Migration Project (RFMP), in coordination with the site XXXX personal, conducted a Radio Frequency (RF) survey at the Site Name WFO in State in Month YEAR. The survey was intended to test and evaluate the RF environment on the WFO’s rooftop and the Upper inflation building.

2 Purpose and Objectives:

This report summarizes the results from an RF survey conducted at City, State from Month/Day/Year to Month/Day/Year. The goal of the survey was to measure the RF environment, and provide assessment and recommendation for a new MROS receive antenna location.

3 Background:

Site history and issues background if exists

4 RF Survey

4.1 Survey Team:

The RF Team visiting the city Name, State name WFO/site included Engineer/Surveyor Names. The RF Team conducted a survey on Month Start day-End day, Year. The site name personnel included local ESA Names and Upper air engineer name.

4.2 Pre-trip survey:

To start the survey, the RF Team obtained data from the FCC and found XXX licensed sites/stations within 100 km.

The sites listed and associated data including frequency and power are shown in Appendix B.

4.3 Site and Survey Equipment

To perform the survey, the RF Team brought a set of RF observation instruments to the city name, state name site. The equipment used for measurement and analysis is detailed below in Table 1.

Table 1: RF Survey Equipment

4.4 WFO Site Set Up and Survey:

Site photos were taken for reference and are included in Appendix A.

At the first location, an omnidirectional antenna was set up on the rooftop of the WFO building (Figure A-7). The antenna height was XX.X feet off the rooftop/ground.

Table 2 shows the Spectrum analyzer parameter settings during the measurements and Table3 shows the receive antenna locations:

Table 2: Spectrum Analyzer Parameter Settings

Table 3: Receive Antenna Locations Altitude is accurate to ± XX meters The RF Team measured and recorded three frequency bands using the Spectrum analyzer name and Spectrum analyzer name spectrum analyzers at different times (morning, afternoon and overnight) using maximum hold features to capture all accurate signal spikes.

There are X active frequencies causing interference; these frequencies should not be used for future testing.

Table 4: To-Avoid Frequency List Scenario 1 At the first location, an omnidirectional antenna was set up on the rooftop of the WFO building (Figure A-7). The antenna height was XX.X feet off the rooftop/ground.

First, a location scan was taken of different frequency bands (Figure A7). The results are shown in Figures 1-3.

Figure-1: First location 400-406 MHz Band Detected

Figure-2: First Location 377-420 MHz Band Detected

Figure-3: First Location 350-450 MHz Band Detected

Table 5: First Location avoid frequency list Scenario 1 -Recommended UHF radiosonde operation frequencies Bands that showed to be avoided are highlighted in red. The cleanest frequencies relative to the rest of the 403 band are the best for use, and are highlighted in green. Finally, there are noisy bands, highlighted in yellow that can be used with caution. Figure 4 shows these frequency bands.

Figure-4: First Location Recommended Frequencies to Avoid/Use

Scenario 2 At the second location, an omnidirectional antenna was set up on a tripod at the WFO yard (Figure A-8). The antenna height was XX.X feet off the ground.

The second location scan was taken of 403 MHz frequency band. The results are shown in Figure 5.

Figure-5: Second Location 400-406 MHz Band Detected

Table 6: Second Location avoid frequency list

Scenario 2 -Recommended UHF radiosonde operation frequencies Bands that showed to be avoided are highlighted in red. The cleanest frequencies relative to the rest of the 403 band are the best for use, and are highlighted in green. Finally, there are noisy bands, highlighted in yellow that can be used with caution. Figure 6 shows these frequency bands.

Figure-6: Recommended Frequencies to Avoid/Use Scenario 3 At the second location, an omnidirectional antenna was set up on a tripod at the WFO yard (Figure A-8). The antenna height was XX.X feet off the ground.

The second location scan was taken of 403 MHz frequency band. The results are shown in Figure 7-8.

This scenario depicts a local NWS high spike for the 403 MHz band and needed action.

Action needed:

Please record and identify all measurements needed.

Send the collected related measurements to the RFMP headquarter to start troubleshoot the problematic/interference signal and rectify it.

Figure-7: Second Location 400-406 MHz Band Detected high noise

Figure-8: Second Location 400-416 MHz Band Detected problematic signal

5. Conclusion:

In conclusion, the RFMP Team conducted a successful RF surveys at XX, XX. The results …

Appendix A – Site Images (examples)

Figure A1 - (Site WFO)

Figure A2 – Site East

Figure A3 – Site West

Figure A4 – Site North

Figure A5 – Site South

Figure A6 – Site oblique view

Figure A7 – Site first location Figure A8 –Site second location (XX.XXX and XX.XXX) (XX.XXX and XX.XXX)

Figure A9 – Tower 1 Directional NWR Antenna Figure A10 – Tower 2 ASOS Omni Antenna

Figure A11 –Tower 3 Figure A12 – Site Upper Inflation Building

Figure A13 – Site Local Radar

Appendix B – Incumbent Sites List

Appendix C – Site/WFO Communications Devices List

Radio Frequency Survey Statement of Work Page 38 of 38

PROCUREMENT SENSITIVE INFORMATION --

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