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             1.  Purpose .......................................................................................................................................... 1

             2.  Description ..................................................................................................................................... 1

             3.  Commercial Companies .................................................................................................................. 2

             4.  Organizational Responsibility ........................................................................................................... 2

1.              Purpose.  The purpose of this chapter is to provide an overview of the current weather radar program and an explanation of the operations and management of associated telecommunications circuits.  This chapter is concerned only with non-NEXRAD radar systems.  NEXRAD communications will be addressed in WSOM
Chapter G-33.

2.              Description.  The NWS Radar Program currently encompasses radar observation stations comprised of 129 network and local warning radars within the 48 contiguous states.  There are 56 network radars, which are a combination of WSR-57 and
WSR-74S type radars; they operate continuously.  There are also 73 local warning radars, consisting of WSR-74C, WSR-74S, and WR100-5 S-band radars, which are operated to more completely provide warning coverage during significant or severe weather phenomena.  Many of these NWS radars are equipped with Federal Aviation Administration (FAA) Radar Remote Weather Display Systems (RRWDS), which provide dial-in or dedicated access to digitized radar data from that site.  In addition, the NWS accesses 22 RRWDS-equipped FAA Air Route Traffic Control radars in the western and southwestern United States.  For operational purposes, these radars are officially designated NWS network radars that provide most of the weather radar coverage for that area.

An external user site might be a Federal agency, state agency, or commercial company.  Typically, any user site dialing in or connected via a dedicated telecommunications line receives its data on a Radar Information Display (RADID) video monitor.  The dedicated access lines may be point-to-point or multipoint and are supplemented with dial-in access lines.  Many of the NWS RRWDS transmitter sites have Multiple Access Dial-up Devices (MADD) that allow multiple RADID users to simultaneously dial-in and obtain radar data.  A typical dial-in call is terminated automatically within 5 to 6 minutes due to a timer incorporated on each MADD circuit card.  This allows the RADID user enough time to obtain at least two full radar scans.

3.               Commercial Companies.  The NWS makes the information from radar sites available to commercial vendors.  These vendors enter into agreements with the NWS to intercept the radar data streams at the network and local warning radar sites.  They are allowed to enhance the digitized radar presentation from the radars and sell the data to interested customers, but the vendors must sign agreements to release the NWS from any liability as a result of their alterations.

4.              Organizational Responsibility.  The Observing Systems  Branch of the Systems Integration Division, Office of Systems Operations, is responsible for managing the overall radar program and all dissemination agreements with vendors who provide data to commercial users.

The Telecommunications and Dissemination Branch of the Systems Integration Division, Office of Systems Operations, is responsible for the following:

                      a.  providing overall technical management of radar data circuitry to ensure efficient and cost-effective operation of the weather radar communications network;

                      b.  monitoring and responding to disruption of communications services through coordination with regional field offices and the telecommunications carriers;

                      c.  providing financial management of the dedicated and dial circuits that constitute the radar data network; and

                      d.  processing NOAA Telecommunications Service Authorization actions to acquire, change, or remove radar telecommunications services and/or facilities at NWS field offices.

The communications managers assigned to each NWS regional Systems Operations Division provide the management and control of regional radar circuits.  These circuits are dedicated point-to- point connections between local warning radar sites and NWS offices.