NOUS41 KWBC 111712



Technical Implementation Notice 12-26

National Weather Service Headquarters Washington DC

112 PM EDT Fri May 11 2012


TO:       Subscribers:

          -Family of Services

          -NOAA Weather Wire Service

          -Emergency Managers Weather Information Network

          Other NWS Partners and Employees


FROM:     Kevin Schrab      

          Chief, Observing Services Division

          Office of Climate, Water, and Weather Services


SUBJECT:  2012 Dates for Termination of Automated Radiotheodolite

          Tracking (ART) and Radio Direction Finding Radiosondes (RDF)

          with Installation of Radiosonde Replacement Systems (RRS)


Three Upper Air (UA) sites are scheduled to begin RRS service in

the next 3 months in 2012.




CARIBOU        72712      KCAR      15 June 2012

GUAM           91212      PGUM      26 July 2012

BARROW         70026      PABR      30 Aug 2012


NWS UA observations will be gathering meteorological data from a

new type of Global Positioning System (GPS) radiosondes, the

Vaisala RS92-NGP.


NWS describes the RRS release point location with the National

Geodetic Survey (NGS) OPUS solution. This is a datum combination

that relies on North American Datum 1983 (NAD83) for latitude

and longitude whereas the release point elevation is based on

North American Vertical Datum 1988 (NAVD88) with the GEOID03

model. By contrast the GPS radiosonde flight information of

latitude and longitude and altitude will rely on the World

Geodetic System 1984 (WGS84) standard.


Parts of the UA coded messages will be significantly longer with

RRS conversion. NWS has coordinated with its partners on the

longer length of these messages.


The format of the messages will be the same WMO format for coded

UA messages used with the MicroArt legacy system. The number of

levels in the coded messages will be two to three times greater

for the TTBB and TTDD. As a result, two categories of AWIPS text

products will increase in size: SGL and ABV. The number of

levels in the TTAA, TTCC, PPBB and PPDD parts will be relatively

unchanged. These changes reflect updated coding practices and

higher resolution level selection criteria. The maximum size

limits of the parts of the coded messages are as follows:


     TTAA:   15 Levels         

     TTCC:   10 Levels        

     TTBB:  135 Levels         

     TTDD:   40 Levels

     PPBB:   40 Levels   

     PPDD:   40 Levels


In addition, each part of the thermodynamic message parts will

include the 31313 message indicator associated with various

parts of the message.


For additional information on the message requirements, please

see the WMO 306 Manual on Codes (International Codes):  Volume

I.1 Part A – Alphanumeric Codes, and Volume II, Regional Codes

and National Coding Practices. Users can find information on the

levels selection criteria used in NWS coding software online at:


If you have questions or feedback, please contact:


  Ivan Navarro

  Engineering and Acquisition Branch

  National Weather Service

  Silver Spring, Maryland 20910

  301-713-1841 Ext. 123


NWS National Technical Implementation notices are online: