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[LDM #VHO-548969]: question about pipes and files



Hi Jon,

You previously sent to Steve Emmerson:
> We'll look at combining the two programs into a single script, but if you 
> have any
> experience determining when the volume-scan is done, I'd appreciate the 
> pointers.
> I did find a website that discussed the radar data format in a bit more 
> detail, but
> I hate to reinvent the wheel if you know a simple way to do this.

The full volume scans are split into lots of pieces (by the
U.S. National Weather Service, not by us or the LDM) which are sent 
individually, AND
there is no guarantee that the pieces will be received in order. One must 
reassemble
the pieces into get a viable, full volume scan.

In case they might be useful to you, I have attached the pattern-action file and
associated Perl script that we use for our THREDDS processing of NEXRAD Level 2
data. The files are:

pqact.threddsradar - the pattern action file we use for NEXRAD2 and NEXRAD3 
processing
for use in THREDDS

hhmmssRadarII.pl - the Perl script that is run from pqact.threddsradar to 
reassemble
the NEXRAD2 pieces

We put 'hhmmssRadarII.pl' in the ~ldm/util directory (and make sure that this 
directory
is in the PATH of the user running the LDM) and pqact.threddsradar in the 
~ldm/etc
directory. The actions in pqact.threddsradar are executed by the following line
in ~ldm/etc/ldmd.conf:

# THREDDS radar processing
exec "pqact -f NEXRAD2|NEXRAD3 etc/pqact.threddsradar"

Please let us know if you have questions about either of these files.

Cheers,

Tom
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Ticket Details
===================
Ticket ID: VHO-548969
Department: Support LDM
Priority: Normal
Status: Closed

Attachment: hhmmssRadarII.pl
Description: Perl program

Attachment: pqact.threddsradar
Description: Binary data


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