# Presentation: 226785

## THE EMWIN TRANSITION

- April 27, 2004
- Angelo Wade, NESDIS Ground Systems

## TOPICS

- BACKGROUND
- TRANSITION CONCEPT
- ACCOMPLISHMENTS

## BACKGROUND

- NOAA had to comply with ITU Regulations
- Power Flux Density
- Spurious emissions
- GOES N/O/P satellite design includes new EMWIN requirements
- Reduced EIRP from 51 dBmi to 44.8 dBmi
- Separate transponder (new freq = 1692.7 MHz)
- Data Rate = 9.6 kbps
- Bandwidth = 50kHz
- Modulation = BPSK

## BACKGROUND (CONT.)

- Transition Plan written as cooperative agreement between NESDIS and NWS principals to transition users from old to new EMWIN
- NESDIS serves as technical lead developing EMWIN hardware/software
- NWS serves as Program lead establishing EMWIN requirements
- Draft Transition Plans have been created and revised frequently since 1999 to coincide with development changes

## TRANSITION CONCEPT

- Develop and test EMWIN-N prototype receiver as proof of concept
- Release of the prototype and development information to prospective vendors
- Broadcast GOES N-type (EMWIN-N) data stream through GOES-11 (stored)
- Broadcast EMWIN-N data stream through the GOES-N satellite during initial checkout period

- “ The Transition Concept is based on the expectation that industry, using NOAA-provided
-  technical information, will produce commercially available receiver systems in a timely
- manner for the user community.”

## TRANSITION CONCEPT

- When to expect change in broadcast?
**The current EMWIN broadcast (EMWIN-I) will most likely be available to users until 2011 if there are no catastrophic failures of major satellite subsystems** **or demand for newer science**
- Change in broadcast service could occur as early as **June 2005** or as late as **Jan 2011** (fuel completely exhausted).
- GOES-11 (currently stored on-orbit) and 12 are expected to have fuel until January and July 2011, respectively
- GOES 8 an 9 are at the end of life
- EMWIN-I long term operations no longer feasible
- GOES-10 is projected to run out of fuel mid 2005 and be replaced by GOES-11 approx. January 2006.

## TRANSITION CONCEPT

- GOES-N call-up scenarios from on-orbit storage
- Critical Factors
- Satellite failure (major subsystems)
- NWS request new satellite
- Improvement in science (e.g., better image resolution)
- Better performance (e.g., precise pointing)
- EMWIN-N scenarios
- Typical Notification of service change
- Users can expect 2.5 months to prepare for new service
- Satellite storage to operations ~ 2.5 months based on GOES-12 replacement of GOES-8 (1 deg/day)

## TRANSITION CONCEPT

- Enough EMWIN-I and N overlap for users to prepare

## TRANSITION CONCEPT

- Planned replacement of older satellites
- GOES-11 (stored) will replace GOES-10 (west)
- GOES-N (not yet launched) replaces GOES-12 (east)
- Testing or changes to satellite operational conditions may require future Plan revisions

## ACCOMPLISHMENTS

- Plan signed December 17, 2003 and posted on NWS website
- Subject to change as requirements evolve
- EMWIN-N publications released to public
- Receiver specifications
- Satellite downlink specifications
- Receiver User Manual and DLLs
- EMWIN-N transmitted through GOES-9 satellite and received successfully
- Characterized (preliminary) performance of EMWIN-N system (uplink and downlink)