20050311: NEXRAD data transformation (cont.)

>From: address@hidden
>Organization: GMU
>Keywords: 200503110302.j2B32Tv2006037 McIDAS FNEXRAD composite

Hi Ying,

>Thank you Tom! I can get the GeoTIFF file, but what I get is pure black: no
>image at all~~~
>
>I tried to use McIDAS to see the straight GINI file, it also shows black when 
>I use IMGDISP, while at the bottom of the window, it does read the time of
>the most recent file.
>
>So, the problem is on the decoded GINI file?

I would guess that this would be the case.

>Could you give me any clue?

I can offer an example pqact.conf entry for the FNEXRAD composites and
what the corresponding entries in LSSERVE.BAT would be:

-- pqact.conf entry --
#
# png compressed 1km radar GINI format
FNEXRAD ^rad/NEXRCOMP/(...)/(...)_(........)_(....)
        PIPE    -close
        decoders/pngg2gini -vl logs/ldm-mcidas.log
        data/gempak/images/sat/RADAR/\1/\2/\2_\3_\4

This will store the uncompressed images in subdirectories of
~ldm/data/gempak/images/sat/RADAR.


-- LSSERVE.BAT entries --

DSSERVE ADD NEXRCOMP/1KN0R-NAT  GINI TYPE=IMAGE 
DIRFILE=/export/data/ldm/gempak/nport/RADA
R/1km/n0r/n0r_* "1 km N0R US Base Reflectivity Composite
DSSERVE ADD NEXRCOMP/2KN1P-NAT  GINI TYPE=IMAGE 
DIRFILE=/export/data/ldm/gempak/nport/RADA
R/2km/n1p/n1p_* "2 km N1P US 1-hr Precip. Composite                 
DSSERVE ADD NEXRCOMP/4KNTP-NAT  GINI TYPE=IMAGE 
DIRFILE=/export/data/ldm/gempak/nport/RADA
R/4km/ntp/ntp_* "4 km NTP US Storm Total Precip. Composite

In this case /export/data/ldm is the same as ~ldm/data.

I assume that you have already done so since you say that you can see the
date/time label in the IMGDISP display, but I feel like I need to remind you 
that
the edited entries in LSSERVE.BAT need to be made active in the 'mcidas' 
account:

<as 'mcidas'>
cd ~mcidas/data
-- edit LSSERVE.BAT; use the value of DIRFILE= as the target of an 'ls' command
   and verify that the files can be seen
cd ~mcidas/workdata
batch.k LSSERVE.BAT

Here are a couple of questions to help troubleshoot:

- what is the output when you run the following as 'mcidas':

cd ~mcidas/workdata
imglist.k NEXRCOMP/1KN0R-NAT.-10

- what are the size of the files that are supposedly being decoded.  If your
  ADDE dataset is setup to point at the uncompressed files, you would still
  get a listing of times, etc. since the file headers are not PNG compressed.
  The files as broadcast should  be on the order of 1 MB each (I'm referring
  only to the 1 km National base refelectivity composites, not the other ones
  that are much smaller).  The size of the files after uncompression will be
  on the order of 14 MB.


>Thank you so much and sorry for keep bothering you..

No worries.

Cheers,

Tom
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