Impacts of switch to GOES-12 as the operational GOES East

As you all know, beginning Tuesday 01 April 2003 at approximately
18:15 UTC, the aging GOES-8 satellite is being replaced with GOES-12
as the operational GOES East satellite.

Impacts to McIDAS users and SSEC Data Center customers
------------------------------------------------------
McIDAS users must be running McIDAS-X Fastrack version 7.803
(08 Dec 2001) or later in order to use GOES-12 data. The only GOES-12
change that has occurred since then is a minor change to the calibration
coefficients in Fastrack version 2002c (11 Feb 2003). McIDAS sites who
have paid for McIDAS-X support can download version 2002c (or the current
version, 2002d) from:
  http://www.ssec.wisc.edu/mug/x/XTOP.html


Users who obtain real-time data products from the SSEC Data Center should 
not see any impact. The GOES-8 data will automatically be replaced with 
the GOES-12 data in your data products.


Users who interactively obtain their real-time GOES East data from
the SSEC Data Center will be able to obtain the data from the same
datasets that currently store GOES-8 data. That is, you will continue to use the
EASTS and EASTL datasets (e.g., EASTS/CONUS) for GOES-12 data as you
currently use them for GOES-8 data. 

Therefore, beginning around 18:15 UTC on 01 April 2003, those datasets
will contain both GOES-8 and GOES-12 images until all of the (old)
GOES-8 images in those datasets are overwritten by new GOES-12 images.

As noted on the web pages above, there are three main differences
between the GOES-8 and the GOES-12 imager instruments.
They are:
 1. The resolution of the GOES-12 water vapor channel (i.e., channel 3)
    is 4 km, as opposed to 8 km on the pre-GOES-12 satellites.
 2. The central wavelength of the GOES-12 water vapor channel is 6.5 um
    as opposed to 6.7 um on earlier satellites. The spectral response
    of the GOES-12 water vapor channel is also wider than those of
    GOES 8-11.
 3. Channel 5 (the 4 km resolution 12 um channel on pre-GOES-12
    satellites) is replaced on GOES-12 by channel 6 (a new 8 km
    resolution channel centered at 13.3 um).

You should not have to make any changes in your McIDAS IMG* commands
(IMGCOPY, IMGDISP, etc.) due to the channel 3 resolution change (#1 above).
For GOES-8 and other pre-GOES-12 satellites the McIDAS data server
automatically doubled the lines to make the water vapor data appear
as 4 km like the other infrared channels. 

The other changes (#2 and #3 above) also do not require any specific
user actions, though you will no longer have access to the 12.0 um
band 5 data because it's being replaced by the 13.3 um band 6 data on
GOES-12.

Impacts to SDI GVAR administrators:
-----------------------------------
Because GOES-12 data will flow through GOES-8 communication links,
SDI GVAR systems running version 2002mar08 or later will automatically
ingest GOES-12 properly and route its data to the same dataset that is
currently receiving GOES-8 data.

Please note, however, that minor GOES-12 imager and sounder calibration
updates were implemented in the current SDI GVAR version (2003feb10).
SDI GVAR sites who have paid for SDI support can download 2003feb10 or
any other version of SDI GVAR from:
  http://www.ssec.wisc.edu/mug/sdi/SDITOP.html

Please feel free to contact the Data Center or the McIDAS Help Desk if you
have any questions.

Thank You,
Dee Wade

--
Dee Wade
McIDAS User Services and SSEC Data Center           Voice: 608.263.0527
Space Science and Engineering Center                Fax: 608.263.6738
University of Wisconsin-Madison                     Web: 
http://www.ssec.wisc.edu/mug
1225 West Dayton Street                                  http://www.ssec.wisc.edu/datacenter 
Madison, WI  53706