Proposed Unidata-Wisconsin Datastream Changes

The UPC is proposing a change in the satellite images being sent in the Unidata-Wisconsin (UNIWISC aka MCIDAS) datastream.

The change would be a combination of:

• a temporal increase in broadcast of both GOES-East (currently GOES-12) and GOES-West (currently GOES-10) images from hourly to half hourly

• an increase in the number of bands (wavelength channels) being sent for each satellite

• an extension of the GOES-East spatial coverage to include South America

• an increase in GOES-East water vapor imagery resolution from 8 km to 4 km

• the addition of SSEC/CIMSS Wildfire ABBA products for North and South America

Proposed changes compared to current broadcast

Current GOES-East Sectors
Band Resolution	Broadcast Frequency	Areal Coverage	Uncompressed Size on Disk
0.65 um Visible	hourly	Northern Hemisphere	2.4 MB
6.5 um Water Vapor	hourly	Northern Hemisphere	607 KB
10.7 um Thermal IR	hourly	Northern Hemisphere	2.4 MB
Proposed GOES-East Sectors
Band Resolution	Broadcast Frequency	Areal Coverage	Uncompressed Size on Disk
0.65 um Visible	half hourly	Northern/Southern Hemisphere Composite	4.4 MB
3.9 um near IR	half hourly	Northern/Southern Hemisphere Composite	4.4 MB
6.5 um Water Vapor	half hourly	Northern/Southern Hemisphere Composite	4.4 MB
10.7 um Thermal IR	half hourly	Northern/Southern Hemisphere Composite	4.4 MB
13.3 um CO2	half hourly	Northern/Southern Hemisphere Composite	4.4 MB

 

Current GOES-West Sectors
Band Resolution	Broadcast Frequency	Areal Coverage	Uncompressed Size on Disk
0.65 um Visible	hourly	Northern Hemisphere	2.4 MB
6.8 um Water Vapor	hourly	Northern Hemisphere	613 KB
10.7 um Thermal IR	hourly	Northren Hemisphere	2.4 MB
Proposed GOES-West Sectors
Band Resolution	Broadcast Frequency	Areal Coverage	Uncompressed Size on Disk
0.65 um Visible	half hourly	Northern Hemisphere	2.4 MB
3.9 um near IR	half hourly	Northern Hemisphere	2.4 MB
6.8 um Water Vapor	half hourly	Northern Hemisphere	613 KB
10.7 um Thermal IR	half hourly	Northern Hemisphere	2.4 MB
12.0 um far IR	half hourly	Northern Hemisphere	2.4 MB

Proposed CIMSS Wildfire ABBA Products
Product Resolution	Broadcast Frequency	Areal Coverage	Uncompressed Size on Disk
WFABBA - NH	three hourly	Northern Hemisphere	2.7 MB
WFABBA - SH	three hourly	Southern Hemisphere	3.8 MB

Notes:

1. the proposed GOES-East sectors are quite a bit larger than the ones currently in the Unidata-Wisconsin datastream. This is especially true for the uncompressed images stored on disk (approx. 2.4 MB versus 4.4 MB). Because of this size difference, the minimum increase in disk space needed (by one appropriately configuring their ~ldm/ldmd.conf file UNIWISC request) would be 4.6 MB per hour of data kept online.

2. the increase in disk space needed to store all images in uncompressed, McIDAS AREA file format is approximately 56 MB per hour of data kept online.

3. the size of the GOES-East compressed products in the UNIWISC stream will vary more than the current images since the southern hemisphere scans are not available for each observation period. Click on goeseast_composite to see the difference in coverage when the southern scan is not available.

4. the product IDD headers will allow sites to select only those images that they want to receive. In particular, users can:
   • keep the temporal frequency at one image per hour
   • choose which bands to get
   • choose which products to get
   • easily get all of the data

5. ldm-mcidas v2002b+ decoders should be installed prior to the proposed data changes. ldm-mcidas v2003 will be released at the end of July, 2003.

6. barring user objections, the broadcast of the proposed images will start at the beginning of September, 2003.

We Want Your Input

Please send all questions, comments, and concerns regarding the proposed changes to support@unidata.ucar.edu.

Tom Yoksas
Unidata User Support
support@unidata.ucar.edu