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[IDD #NWC-373741]: LDM installation/setup



Hi Var,

re:
> With your advise below, we are now able to download NEXRAD data.

Very good.

> Our requested feed types are NNEXRAD, UNIWISC, FSL2 on idd.cise-nsf.gov.

OK.

> To answer your question below, our objective is to assimilate these data into 
> a
> weather model (called ARPS) for initialization.
> 
> The model that we use has packages that can convert satellite AREA data and
> NEXRAD nids data into hdf4 format for this purpose.

OK.  The NNEXRAD data is in NIDS format.  The UNIWISC satellite imagery,
however, is in PNG-compressed AREA format.  In order to use your routines, you
will need to uncompress the UNIWISC images.  This is easily accomplished with
the 'pnga2area' routine that is part of the 'ldm-mcidas' package that is
freely available from us.  Assuming that your LDM machine is running Linux,
you should be able to download a binary distribution of ldm-mcidas from us
as follows:

<as 'ldm'>
cd ~ldm
mkdir decoders util
mkdir ldm-mcidas
cd ldm-mcidas
ftp ftp.unidata.ucar.edu
  <user> anonymous
  <pass> address@hidden
  cd pub/binary/linux_2.6-i686        <- assuming your 32-bit machine is 
running the 2.6 kernel
  binary
  get ldm-mcidas-2004.tar.Z
  quit

zcat ldm-mcidas-2004.tar.Z | tar xvf -
ln -s ldm-mcidas-2004 runtime
ln -s runtime/* .

ldd bin/pnga2area

-- if the output from 'ldd' indicates that the executable will work on your 
system then
   do:

cp bin/pnga2area ~/decoders

Next:

cp etc/SAT* ~/etc

-- copy the contents of etc/ldm-mcidas-pqact.conf.all into ~ldm/etc/pqact.conf
   This is best done by editing ~ldm/etc/pqact.conf with 'vi' and reading the 
contents
   of ~ldm/ldm-mcidas/etc/ldm-mcidas-pqact.conf.all into the end of pqact.conf

ldmadmin pqactcheck

If there are no errors indicated by 'ldmadmin pqactcheck', then send a HUP 
signal
to 'pqact' telling it to reread ~ldm/etc/pqact.conf:

ldmadmin pqactHUP          <- or you could stop and restart your LDM

NOTEs:

- the actions in ldm-mcidas-pqact.conf.all are setup for a very specific
  directory structure hierarchy.  You may want to change this to suit your
  needs

The first action in ldm-mcidas-pqact.conf.all is one that you will likely
want to comment out.  I.e.:

change:

UNIWISC ^pnga2area Q. (..) (.*) (.*) (.*) (.*) (........) (....)
        PIPE    -close
        pnga2area -vl logs/ldm-mcidas.log
        -a etc/SATANNOT
        -b etc/SATBAND
        -d data/mcidas -r \1,\2

to:

#UNIWISC ^pnga2area Q. (..) (.*) (.*) (.*) (.*) (........) (....)
#        PIPE    -close
#        pnga2area -vl logs/ldm-mcidas.log
#        -a etc/SATANNOT
#        -b etc/SATBAND
#        -d data/mcidas -r \1,\2

Of course, anytime you make modifications to a pqact pattern/action file
(e.g., ~ldm/etc/pqact.conf), you will need to verify that there were
no typos or syntax problems using:

ldmadmin pqactcheck

> As we are new to LDM and these radar/satellite data format (for that matter), 
> I
> am assuming that, at this point, we would just need to FILE the UPSTREAM data
> locally prior to further processing for our model.

Yes for the NNEXRAD products; no for the UNIWISC products.  Please see above.

> Still, we are uncertain as
> to whether these uploaded data are in the right format or that further 
> decoding
> is needed by packages like Gempak or McIdas.

The ldm-mcidas utility 'pnga2area' is all you need to uncompress the UNIWISC 
images.

> We are using IDV now to display some of these data.

Very good.

> To file these data, how do we modify the pqact.conf file? Is it the same
> format as suggested below?

Please review the actions contained in the ldm-mcidas-pqact.conf.all file
I reference above.

> Thank You again. Your team has been extremely helpful thus far!

No worries.

Cheers,

Tom
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Ticket Details
===================
Ticket ID: NWC-373741
Department: Support IDD
Priority: Normal
Status: Closed


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