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L ow R ate I nformation T ransmission. Product Suite. Charles Vance charlie.vance@noaa.gov. 1. Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002. L R I T. Sometimes referred to as: Digital WEFAX High Speed WEFAX
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LowRateInformationTransmission Product Suite Charles Vance charlie.vance@noaa.gov 1 Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002
L R I T • Sometimes referred to as: • Digital WEFAX • High Speed WEFAX • Next Generation WEFAX • LRIT is more than WEFAX 2 Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002
WEFAX (Weather Facsimile) Transmits only images using low rate facsimile, 24 hours a day on a fixed schedule of 4 and 5 minute time slots 01:00 17Z 72Hr MSLP/1000-500 THK 01:05 17Z 72Hr 500MB HT PA33 W502 01:10 GOES-8 2345Z NE IR 01:14 GOES-8 2345Z SE IR 01:18 GOES-8 2345Z NW IR 01:22 GOES-8 2345Z SW IR 01:26 GOES-8 2345Z 4KM US IR 01:30 GOES-8 2345Z 16KM FD IR 01:34 GOES-8 2345Z NH WV 01:38 GOES-8 2345Z NE WV 01:42 GOES-8 2345Z SE WV 01:46 GOES-8 2345Z NH WV 01:50 GOES-8 2345Z SW WV 01:54 GOES-8 0045Z NH IR 01:58 GOES-8 2345Z 16KM FD WV Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002 3
L R I T(More than WEFAX) • Integrated Stream of Digital Products that can be Transmitted Asynchronously • Improved Image Resolution • Can Utilize Compression • Diverse Product Suite • Digital Text Messages! 4 Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002
Initial LRIT Product Suite • Used WEFAX as a Baseline and • Reduced latency • Increased resolution • Improved user flexibility • Also added other services such as • NWS messages including EMWIN • DCS • Evolving Capabilities and Products Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002 5
Geostationary Satellite Data Polar Satellite Data Text and Administrative Messages L R I T Integrated Stream of Digital Products • NWS Data (including) • Models/Charts • EMWIN GOES Data Collection Service Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002 6
GOES Imagery ExampleWEFAX Limitations • Resolution Limitations • Pixel Area limited by 2.4KHz modulation • Pixel Depth (brightness) roughly 6.5 bits • Latency • One Daytime GOES Full Disk Ingest generating 14 WEFAX image products takes 56 minutes to transmit • Initial processing delays of 25 minutes • Scheduling – images sent one after another 7 Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002
16 KM Full Disk 4 KM CONUS IR WV IR VIS 14 WEFAX PRODUCTS FROM 1 DAYTIME FULL DISK 8 KM Northern Hemisphere and Quadrants IR IR VIS VIS IR WV IR IR VIS VIS Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002 8
LRIT Transmits Full Disk in near real time segments for improved reliability and less latency User can generate sectors for areas of interest Missing segment does not negate entire transmission Total Transmission time of approximately 20-25 minutes Slightly longer than normal GVAR transmission Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002 9
LRIT Viewer Screen Shot GOES-10 8 Km IR 10 Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002
LRIT Viewer Screen Shot GOES-10 8 Km IR Missing Segment w Overlays 11 Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002
LRIT Viewer Screen Shot GOES-10 8 Km IR Missing Segment w Zoom 12 Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002
LRIT Viewer Screen Shot GOES-8 8 Km IR 13 Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002
LRIT Viewer Screen Shot GOES-8 8 Km IR with Zoom and Overlay 14 Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002
GOES Imagery ExampleLRIT Improvements • Resolution • Pixels per line variable and ‘unlimited’ • Pixel Depth of 8 bits (generally) • Latency • Initial processing delays minimized • One Daytime GOES Full Disk Ingest sent in segments taking 20 – 25 minutes to transmit • Scheduling – multiple products sent ‘simultaneously’ 15 Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002
LRIT Viewer Screen Shot (Compressed) GMS with ZOOM (Embedded Overlays) 16 Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002
LRIT Receiver Screen Shot 17 Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002
Time Share of WEFAX and LRIT During Transition Reduced Product Suite for Each Service Alternates Each Hour • LRIT • GOES • NWS products • Models/Charts • EMWIN • GMS • GOES DCS channel? WEFAX GOES Images NWS Charts GMS Meteosat? 00 55 05 50 10 15 45 40 20 35 25 30 18 Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002
Summery • LRIT is an Integrated Stream of Diverse Digital Products that can be Transmitted Asynchronously and has Reduced Latency, Improved User Flexibility, Increased Resolution, and Increased Reliability compared to WEFAX • The LRIT Product Suite is User Driven 19 Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002
Are you ready? • Email: LRIT@NOAA.GOV • http://www.osdpd.noaa.gov/COB/COB.html • http://noaasis.noaa.gov/WEFAX/ ( /LRIT/ ? ) • http://www.nws.noaa.gov/datamgmt/doc/lrit.html 20 Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002