[IDD #SJH-789523]: LDM - High Resolution visible images

["Unidata IDD Support" <support-idd@xxxxxxxxxxxxxxxx>]

Hi Eric,

re:
> Currently at the university of miami - RSMAS, we are receiving the 4 km
> visible satellite imagery. I have been told that it is possible to obtain
> higher resolution images through the LDM. 

The NIMAGE datastream has the 1 km Vis images that are in the NOAAPort
broadcast.  These images have been remapped into a conical projection (i.e.,
they are not in the original satellite projection).

> If so, could you tell me how to modify the pqact configuration to do so.

The ~ldm/etc/ldmd.conf file is where data requests are made.  ~ldm/etc/pqact.conf
is where the pattern-actions are placed for processing the products.

A typical ldmd.conf entry that requests all of the images in the NIMAGE
datastream would look like:

request NIMAGE ".*" upstream.feed.host

If you want to receive only the 1 km VIS images, you will need to replace
the ".*" regular expression with one that limits the request to just the
VIS images.

Question:

Which software package do you intend to use to look at the images (e.g., GEMPAK,
McIDAS, other)?

The action(s) you use in a pqact.conf pattern-action file will likely depend on
how you intend to use the images after they are received. That being said, the
following pqact.conf action will FILE all of the products in the NIMAGE datastream:

# All NOAAPORT Zlib-compressed (satz) GINI NOAAPORT images
NIMAGE  ^satz/ch[0-9]/.*/(.*)/([12][0-9])([0-9][0-9])([01][0-9])([0-3][0-9]) ([0-2][0-9])([0-5][0-9])/(.*)/(.*km)/
        FILE  /machine/data/ldm/mcidas/images/sat/\8/\9/\1/\1_\2\3\4\5_\6\7

NOTEs:

- a number of the white spaces in pattern-actions are tabs, not spaces!
- the directory structure you use for FILEing the products depends on your
  setup
- the above action does not uncompress the images.  It writes them as broadcast
  into disk files.  Current versions of McIDAS and GEMPAK can use the compressed
  images directly.  If you will be using the images in some other application,
  you will likely need to uncompress them before they will be useful.  The
  ldm-mcidas package contains an application, zlibg2gini, to uncompress the images.
- you must worry about scouring images after they have been written.  If you don't
  your disk will eventually fill up.
- finally, if you need the images in their native (unremapped) projection, you
  will need to use something like McIDAS or the IDV to request the images from
  a McIDAS ADDE server.  More information on this if you are interested.

> Much thanks,

No worries.

Cheers,

Tom
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Ticket Details
===================
Ticket ID: SJH-789523
Department: Support IDD
Priority: Normal
Status: Closed