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20000731: Unidata-Wisconsin datastream image compression change

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  • Subject: 20000731: Unidata-Wisconsin datastream image compression change
  • Date: Mon, 31 Jul 2000 14:58:59 -0600
>From: Robert Mullenax <address@hidden>
>Organization: NMSU/NSBF
>Keywords: 200007312038.e6VKcuT14730 Unidata-Wisconsin MCDIAS PNG ldmd.conf 
>pqact.con

Robert,

>So I should make this change now in my ldmd.conf?
>
>to the request...........  cirrus.al.noaa.gov (getting all images) as you 
>state?

I would, yes.  If neither psnldm nor wxmcidas are feeding any other
machines, you can cut down the amount of data hitting them by modifying
your MCIDAS request line to ask only for the PNG compressed imagery.
The reason?  Right now, you have about 1.5 (to 1.6) times the amount of
image data arriving at your machine(s).  Eliminating the request for
delta-encoded images will drop this down to 0.5 times the amount it was
with only the delta encoded images were being sent.  Relay sites, on
the other hand, can't make the change until all of their downstream feeders
have made the transition.

I, therefore, recommend that you change your MCIDAS request in ldmd.conf
to:

request MCIDAS "^pnga2area Q[01]" cirrus.al.noaa.gov

or

request MCIDAS "^pnga2area Q." cirrus.al.noaa.gov

and then stop and restart your LDM.  This assumes, of course, that you
have made the needed entry changes to your pqact.conf file!  Generic
pqact.conf changes for sites used to using the McIDAS routing table to
name output AREA files would be something like:

#
# PNG-encoded CIMSS product AREA files:
#
MCIDAS  ^pnga2area Q0 (..) (.*) (.*) (.*) (.*) (........) (....)
        PIPE    -close
        pnga2area -vl logs/ldm-mcidas.log -d data/mcidas -r \1,\2
#
# PNG-encoded AREA files:
#
MCIDAS  ^pnga2area Q1 (..) (.*) (.*) (.*) (.*) (........) (....)
        PIPE    -close
        pnga2area -vl logs/ldm-mcidas.log -d data/mcidas -r \1,\2

ROUTE PostProcess BATCH files continue to work when using this method
of invoking pnga2area.

>Thanks,

Later...

Tom

>From address@hidden Mon Jul 31 16:22:45 2000
>Subject: Re: 20000731: Unidata-Wisconsin datastream image compression change 

Thanks Tom,

Yes I made the changes to the pqact.conf when I got the
ldm-mcidas-7.6.3 installed.  I'll make these changes tonight.

Robert

>From address@hidden Tue Aug  1 13:48:20 2000
>Subject: Re: 20000731: Unidata-Wisconsin datastream image compression change 

Tom,

I made the changes this morning. Everything seems to be working fine..
and we even have some rain the area..good on all counts!