[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

19991026: NOAAPort GOES Imagery



>From: address@hidden (Larry "The Weather Man" Riddle)
>Organization: University of California/Scripps
>Keywords: 199910261825.MAA22557 Unidata-Wisconsin

Larry,

>       At the UserComm meeting someone (I believe it was you) mentioned
>       the possibility that much more GOES imagery would be coming down
>       the NOAAPort pike sometime in the future.  If I recall correctly,
>       "higher resolution" and "more bands" were mentioned.

Yes, or contractual arrangement with SSEC allows for us to start sending
more data.  What data gets included in the IDD was one of the things
that I had hoped would be more of a topic of discussion at the User
Committee meeting, but time ran out (one of the reasons for two full
day meetings :-).

>       Where can I find out more information on this?

What are you looking to find out?  There has not been a definite strategy
defined for what will change.  We did kick around several ideas, however.
First off, we will be changing how the images are compressed for transmission.
Experiments that Chiz ran on GINI imagery from NOAAPORT demonstrated that
we can achieve a doubling of data while maintaining the number of bytes
sent.  Couple this with a doubling or tripling of the data products, and
we will be looking at an increase of between 4 and 6 times the amount of
imagery in the Unidata-Wisconsin datastream.

>I've looked at
>       the NOAAPort contents section of the Unidata web page, but it 
>       doesn't have the info I'm being asked for.  I'm supposed to get
>       technical specifications on the imagery (resolution, bands, any
>       remapping, and so on) on the current and future imagery.

The imagery in the Unidata-Wisconsin datastream is not remapped, but it
is sampled.  GOES imagery is oversampled in the "element" (i.e.
longitudnal) dimension by a factor of 1.7.  The images we send in the
UW stream are "blown down" (McIDAS terminology) by a factor of two.
What this really means is that every other pixel is sent in the element
dimension.  Since the IR bands are already at their maximum resolution
(4 km), there is no need to sample in that dimension.

Now the question becomes one of how to increase the datastream
products:  higher temporal resolution or higher/more spatial
resolution?  The other possibility is to setup a series of new floater
products that would be selectable by different parts of the country.
With more floaters, one could imagine that sites could get higher
resolution visible imagery for their neck of the woods without the
overhead of sending 26 MB images across the IDD.  These sorts of
questions are really what the User Committee should direct us on.

For more information on the imagery available from SSEC (i.e. GOES and
POES), you should review the following URLs:

http://psbsgi1.nesdis.noaa.gov:8080/noaasis.html
  Information Gateway
  http://psbsgi1.nesdis.noaa.gov:8080/EBB/ml/nic000.html
    General overview of the U.S. NOAA geostationary ...
    http://psbsgi1.nesdis.noaa.gov:8080/EBB/ml/nic1.html
      Imager
      http://psbsgi1.nesdis.noaa.gov:8080/EBB/ml/gsensor.html
      Sounder
      http://psbsgi1.nesdis.noaa.gov:8080/EBB/ml/gsensor1.html

Now, if your question was about imagery in the actual NOAAPORT datastream,
then I can point you to:

NOAAPORT Home Page
http://www.nws.noaa.gov/noaaport/html/noaaport.shtml
  NOAAPORT Data Characteristics
  http://www.nws.noaa.gov/noaaport/html/data.shtml
    NOAAPORT channels
    http://www.nws.noaa.gov/noaaport/html/channels.shtml

The NOAAPORT datastream currently contains remapped GOES-East and GOES-West
imagery on a variety of locations.  Generally, the bands available are
from the GOES imager: Visible, 3.9 um, 6.8 um, 10.7 um, and 12.0 um.
The resolution of the imagery depends on which product you are looking at.
Various documents available under the NOAAPORT Data Characteristics page
can give you more specifics.  Generally, however, imagery is availabe as
1 km visible in Lambert Conformal tangent cone projection, all of the
infrared channels except water vapor as 4 km products also in Lambert
Conformal tangent cone projection, and water vapor in Lambert Conformal
tangent cone.  Alaska, Hawaii, and Puerto Rico images will be in either
Polar Stereographic (Alaska) or Mercator projections and can have different
resolutions (e.g. 2 km VIS; 8 km IR; and 16 km WV for Alaska).

Is this the sort of information you were looking for?

>       Sorry to be such a pain.

No problem.

Tom
--
+-----------------------------------------------------------------------------+
* Tom Yoksas                                             UCAR Unidata Program *
* (303) 497-8642 (last resort)                                  P.O. Box 3000 *
* address@hidden                                   Boulder, CO 80307 *
* Unidata WWW Service                             http://www.unidata.ucar.edu/*
+-----------------------------------------------------------------------------+