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[LDM #NTO-640607]: HRRR access through ldm


> I'm new to ldm and I'm trying to configure it to access HRRR analysis data
> from idd. I saw this email thread:
> https://www.unidata.ucar.edu/support/help/MailArchives/idd/msg06476.html
> But I'm not sure how pq.conf should be set up to retrieve the data.

The process of one's local LDM being fed data products by one or more
"upstream" LDMs is as follows:

- download, build and install the latest version of the LDM

- determine which data feed(s) have the data desired

- edit the LDM configuration file, ~ldm/etc/ldmd.conf, with one or more
  REQUEST entries to request feeds of the data stream(s) desired to
  be received

  LDM configuration file REQUEST entries look like:


  For instance, here is an entry that will request the HRRR data that you would
  see in the 'notifyme' invocation that you included in your inquiry:

  REQUEST   NGRID  "HRRR"  idd.unidata.ucar.edu

- add an EXEC entry to the LDM configuration file to process the products
  specified in the REQUEST line(s) added

  An LDM configuration file REQUEST line will look like:

  EXEC<tab>"pqact -f <feed> <LDM pattern-action file>"

  For example, an EXEC line for the HRRR data that would be REQUESTed by the
  example REQUEST line above would be:

  EXEC "pqact -f NGRID /usr/local/ldm/etc/pqact.conf_hrrr"

- create the LDM pattern-action file with the action(s) you wish to have
  run by the 'pqact' instance that will be created from the EXEC line
  example above

  What you want to do with the data products you received is only limited
  by your imagination :-)  As an example, however, try the following:

# =====================================
# = HRRR model data available via IDD =
# =====================================
# ---------------------------------------------
# - NCEP High Resolution Rapid Refresh (HRRR) -
# ---------------------------------------------
# High Resolution Radid Refresh (HRRR) grid output from NCEP
# Based on http://www.nws.noaa.gov/os/notification/tin14-28hrrr-aac.htm
# Forecast Grids
NGRID   ^Y.C.* KWBY (..)(..).*F([0-9][0-9][0-9])
#  http://www.nco.ncep.noaa.gov/pmb/docs/on388/appendixa.html
# Analysis Grids
NGRID   ^Y.CA.* KWBY (..)(..)

  Please not carefully:

  - the form of action entries in a pattern-action file is fixed:


  So, the first action listed above (which does NOT have tabs where needed) can 
be read as:

NGRID<tab>^Y.C.* KWBY (..)(..).*F([0-9][0-9][0-9])

> I did notifyme -vl- -h idd.unidata.ucar.edu    -f ANY -p "HRRR*" -o 36000
> and see the following:
> 14015000.165444 NGRID 27127609  YTCA98 KWBY 140100 
> !grib2/ncep/HRRR/#255/202008140100F000/TMP/2 m HGHT
> 20200814T031038.825201Z notifyme[8513]              
> notifyme.c:notifymeprog_5:212       INFO     1594886 202008
> 14015000.917171 NGRID 27127610  YACA99 KWBY 140100 
> !grib2/ncep/HRRR/#255/202008140100F000/DPT/1000 hPa PRES

Excellent!  Learning how to use the LDM utility 'notifyme' will make your job
of configuring and monitoring your LDM MUCH easier as you go on!

> I wonder if anyone can help provide a template  "pq.conf" for retrieving the 
> data?

I am assuming your "pq.conf" is a reference to an LDM pattern-action file.  No 
the name of the pattern-action file is not important.  For convenience, 
however, it
is best practice to store all pattern-action files in the LDM 'etc' directory,


The LDM operates in two semi-distinct parts:

- getting and relaying data products

- doing something with data products that have been received

If you continue to have problems, please send us your LDM configuration
and pattern-action files.  Please send these as attachments, not as
cut and paste listings since we can not check to see if there are any
typos (e.g., spaces where tabs are required) in your entries.


Unidata User Support                                    UCAR Unidata Program
(303) 497-8642                                                 P.O. Box 3000
address@hidden                                   Boulder, CO 80307
Unidata HomePage                       http://www.unidata.ucar.edu

Ticket Details
Ticket ID: NTO-640607
Department: Support IDD
Priority: Normal
Status: Closed
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