20041206: LDM configuration for GEMPAK decoding

>From:  Mark Seefeldt <address@hidden>
>Organization:  CU
>Keywords:  200412062152.iB6LqplI011140 LDM GEMPAK ldmd.conf pqact.conf

Hi Mark,

>I now have LDM and Gempak installed and I am at the final stage of 
>configuring the ldmd.conf, pqact.conf, scour.conf files.

Sounds good!

>The ldmd.conf file appears to be reasonably simple, except for calling the 
>specific types of data.

I am not sure what you mean here.  I am assuming your comment means
that the content of the different datastreams available in the IDD
is not obvious, true?

>I have created a pqact.gempak file using the gen_pqact.csh script.  My take 
>is that I just copy that into pqact.conf, and all should be happy.

The gen_pqact.csh script should have told you what action you need
to take to activate the processing actions.  The two basic options
are to do like you said, include the actions in ~ldm/etc/pqact.conf,
and to add extra 'exec "pqact..."' actions in ~ldm/etc/ldmd.conf making
sure to specify the name of your pattern action file in the action.

>The scour.conf file looks basic once I know what types of data I am
retrieving.

The LDM 'scour' utility can scour any directory for which the user
running it has appropriate permissions.  The one thing to remember
about 'scour' is that it scours on a per-day basis.  Some data 
may be better scoured on a per file basis (e.g., NEXRAD Level II or
III radar data; UNIWISC satellite imagery, etc.).  For those
scouring jobs we provide some scripts that can be run out of cron.
The scripts can be found in the pub/ldm/scour directory of anonymous
FTP on our FTP server, ftp.unidata.ucar.edu:

% ls ~ftp/pub/ldm/scour
scourBYday.tcl*      prune_images.csh*    prune_gini.csh*
scourBYnumber.tcl*   prune_nexrad.csh*    scour_bynumber.csh*
scour*               prune_nexrcomp.csh*

>According to the above, that just leaves me with figuring out the 
>instructions to retrieve the specific types of data.  Any 
>suggestions/resources/samples that I can use to determine how to configure 
>retrieval of the data.  I am not looking for much with the data, surface 
>observations, upper air observations, and probably Eta model output is all 
>we need right now.  More is fine, but not necessary.

All of the observational data is contained in the ID|DDPLUS datastream.
This stream has the lowest volume of data of all of the NOAAPORT
streams (which are HDS, IDS|DDPLUS, NIMAGE, NNEXRAD), so requesting
all of the feed is the easiest thing to do:

request IDS|DDPLUS      ".*"    <your_upsteam_IDD_feed_host>

(replace <your_upsteam_IDD_feed_host> with the fully qualified hostname
of the IDD host you will request IDS|DDPLUS data from)

As far as requesting a subset of the HDS (NOAAPORT broadcast NCEP
model output), the best thing to do is to use the LDM 'notifyme'
facility to get an idea of what is in the datastream:

as user running the LDM on your system:

notifyme -vxl- -f HDS -o 3600 -h <your_upsteam_IDD_feed_host>

The headers that will be listed for the most part follow WMO
conventions.  What is not provided in those conventions is added
by our IDD ingest process, namely the 'meta' tag.

Here is an example of using notifyme to list out all of the ETA model
output your upstream feed host has received in the past hour (3600
seconds):

notifyme -vxl- -f HDS -o 3600 -p /mETA -h <your_upsteam_IDD_feed_host>

Specification of the 'meta' (/m) tag in your request line will limit
what you are sent:

request HDS     "/mETA" <your_upsteam_IDD_feed_host>

By the way, this kind of information is available in the LDM Basics
pages on our web site:

http://www.unidata.ucar.edu/content/software/ldm

>Thanks

Please let me know if the above is sufficient to get you going.

Cheers,

Tom
--
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* Tom Yoksas                                             UCAR Unidata Program *
* (303) 497-8642 (last resort)                                  P.O. Box 3000 *
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