EMWIN-N Prototype Tests Completed:

 

Another milestone has been reached in the EMWIN-N transition, with the successful test of the prototype EMWIN-N receiving system, conducted September 6 – 15, 2006 at the NESDIS Command and Data Acquisition (CDA) Station in Wallops Virginia.  The final test report validates the proof-of-concept for the EMWIN-N system and indicates it is ready for further development by prospective manufacturers. 

 

During the test, an uplink transmitter at the Wallops CDA beamed an EMWIN-N test signal to the recently orbited GOES 13 satellite (previously identified as GOES-N) which retransmitted a broadcast signal back to Wallops where it was received and decoded by the prototype EMWIN-N receiver.  The test data showed that the performance fully met the design criteria for error rate using a one meter dish receiving antenna with a very satisfactory operating margin against adverse radio broadcast conditions.    

 

The GOES 13 satellite is currently located near 90 degrees west and its EMWIN-N test broadcast will remain available to prospective manufacturers until early December, 2006.   The broadcast coverage area for GOES 13 includes the continental United States so that anyone with a receiver comparable to the NOAA prototype should be able to receive the test signal.  These successful tests now open the way for another user-vendor conference for which the schedule and details will be announced on the EMWIN website once they become firm.

Background Information:

Successful results from final EMWIN-N tests Sept. 2006 at the Wallops CDA up-link.
Successful results from the tests performed in 2005 at the Wallops CDA up-link.

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EMWIN-N Prototype:

To allow for an easier transition the EMWIN-N prototype receiver was designed to receive both the current broadcast (EMWIN-I) and the EMWIN-N broadcast.  With the advent of the EMWIN-N broadcast the data rate will double to 19.2 kbps, use offset quadrature phase shift keying (OQPSK) modulation, and employ error correction coding for additional gain. The EMWIN-N prototype receiver specification is available for download.  This prototype uses new software-defined radio technology, relatively new to NOAA dissemination systems.  This document may prove useful to any potential manufacturers interested in building and marketing EMWIN-N receivers. In addition to the specification, the demodulation and decoding software is also available.

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Other News:

In other developments, the EMWIN team is working with NWS International Affairs to develop a pilot project to help support the Third Border Initiative (TBI). This project would supply current generation EMWIN systems to several Caribbean Island nations. Training and technical support on the installation and use of EMWIN receivers will be provided to a small group of meteorological and emergency management representatives from those nations.

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EMWIN-N Background:

Changes in the next series of GOES satellites, the GOES-N thru P constellation, have necessitated development of EMWIN-N. Sometime before 2011 the current GOES satellites will be removed from operation and will be replaced by the new series. All current EMWIN users will need to migrate to newer technologies due to frequency, power and modulation changes. In addition, EMWIN users and vendors have also stressed the importance of increasing the EMWIN data rate and keeping the cost of the GOES-N transition as low as possible. The EMWIN team together with NESDIS has been developing a design to meet these needs.