# Presentation: 651774

## Low Rate Information Transmission

**Product Suite**

- Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002

**Charles Vance                     **charlie.vance@noaa.gov

## L R I T

- Sometimes referred to as:
- Digital WEFAX
- High Speed WEFAX
- Next Generation WEFAX
- LRIT is more than WEFAX

- Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002

## WEFAX

** ****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**

- (Weather Facsimile)
- Transmits only images using low rate facsimile, 24 hours a day on a fixed schedule of 4 and 5 minute time slots

| PRODUCTS |  |
| --- | --- |
| GOES EAST | GOES WEST |
| 135 GOES | 132 GOES |
|  59 NWS Charts |  58 NWS Charts |
|  44 NOAA Polar |  44 NOAA Polar |
|   2 TBUS 3 msg files |   2 TBUS 3 msg files |
|  67 Meteosat |   7 Meteosat |
|  |  40 GMS |

- Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002

## 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!

- 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

- Polar Satellite Data

- GOES Data Collection Service

- NWS Data (including)
-  Models/Charts
-  EMWIN

- L R I T

**  ****Integrated Stream of Digital Products     **

- Text and Administrative
-            Messages

- Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002

## GOES Imagery Example WEFAX 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

- Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002

## 14 WEFAX PRODUCTS FROM 1 DAYTIME FULL DISK

- 8 KM Northern Hemisphere and Quadrants

- 16 KM Full Disk

- 4 KM CONUS

- IR

- WV

- IR

- VIS

- IR

- WV

- IR

- IR

- IR

- IR

- VIS

- VIS

- VIS

- VIS

- Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002

## LRIT Transmits Full Disk in near real time segments for improved reliability and less latency

**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

## LRIT Viewer Screen Shot

- GOES-10 8 Km IR

- 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

- 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

- Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002

## LRIT Viewer Screen Shot

- GOES-8 8 Km IR

- 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

- Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002

## GOES Imagery Example LRIT 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’

- Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002

## LRIT Viewer Screen Shot

- (Compressed) GMS with ZOOM (Embedded Overlays)

- Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002

## LRIT Receiver Screen Shot

- Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002

## Time Share of WEFAX and LRIT

-              During Transition

- 05

- 00

- 30

- 50

- 15

- 45

- 40

- 55

- 10

- 20

- 25

- 35

- Reduced Product Suite for Each Service

- Alternates Each Hour

**WEFAX**
- GOES Images
- NWS Charts
- GMS
- Meteosat?

**LRIT**
- GOES
- NWS products
-  Models/Charts
-  EMWIN
- GMS
- GOES DCS channel?

- 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

- 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

- Satellite Direct Readout Conference for the Americas in Miami, Florida December 9-13, 2002