20050313: NEXRAD data transformation (cont.)

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

Hi Ying,

>After my trial, I can get N0R data in GeoTIFF but not for N1P or NTP...

They should be transformable to GeoTIFF in the same manner.

re: what does imglist.k output look like

>They seem ok:
>Image file directory listing for:NEXRCOMP/1KN0R-NAT
> Pos Satellite/         Date       Time      Center   Band(s)
>     sensor                                 Lat  Lon
> --- -------------  ------------  --------  ---- ---- ------------
> 318  RADAR         13 MAR 05072  22:00:00     TWX    27
>
>Image file directory listing for:NEXRCOMP/2KN1P-NAT
> Pos Satellite/         Date       Time      Center   Band(s)
>     sensor                                 Lat  Lon
> --- -------------  ------------  --------  ---- ---- ------------
> 489  RADAR         13 MAR 05072  22:01:00     TWX    30
>
>Image file directory listing for:NEXRCOMP/4KNTP-NAT
> Pos Satellite/         Date       Time      Center   Band(s)
>     sensor                                 Lat  Lon
> --- -------------  ------------  --------  ---- ---- ------------
> 553  RADAR         13 MAR 05072  22:03:00     TWX    31
>imglist.k: done

These do look OK.

re: what are sizes for decoded files

>It's 14M for N0R data, 3.4M for N1P and 868K for NTP.

These are correct.

>I use the following in pqact.conf:
>FNEXRAD ^rad/NEXRCOMP/(...)/(...)_(........)_(....)
>        PIPE    -close
>        decoders/pngg2gini -vl logs/ldm-mcidas.log
>        data/gempak/nexrad/NEXRCOMP_GINI/\1/\2/\2_\3_\4

OK.

>by checking the log file, I found:
>^@Mar 13 23:22:46 pngg2gini[6502]: Starting Up
>^@Mar 13 23:22:46 pngg2gini[6502]: output file pathname: data/gempak/nexrad/NE
> XRCOMP_GINI/1km/n0r/n0r_20050313_2333
>^@Mar 13 23:22:46 pngg2gini[6504]: Starting Up
>^@Mar 13 23:22:46 pngg2gini[6504]: output file pathname: data/gempak/nexrad/NE
> XRCOMP_GINI/2km/n1p/n1p_20050313_2334
>^@Mar 13 23:22:46 pngg2gini[6502]: unPNG::  1084716  14208533  13.0989
>^@Mar 13 23:22:46 pngg2gini[6502]: Exiting
>^@Mar 13 23:22:46 pngg2gini[6522]: Starting Up
>^@Mar 13 23:22:46 pngg2gini[6522]: output file pathname: data/gempak/nexrad/NE
> XRCOMP_GINI/4km/ntp/ntp_20050313_2335
>^@Mar 13 23:22:46 pngg2gini[6504]: unPNG::    69405   3552533  51.1855
>^@Mar 13 23:22:46 pngg2gini[6504]: Exiting
>^@Mar 13 23:22:46 pngg2gini[6522]: unPNG::    26162    888533  33.9627
>^@Mar 13 23:22:46 pngg2gini[6522]: Exiting
>
>It seems the decoder doesn't work for n1p and ntp.

Your output shows that the decoder is working.  Here is your same listing
reordered so that all output lines from individual invocations are put
together:

Mar 13 23:22:46 pngg2gini[6502]: Starting Up
Mar 13 23:22:46 pngg2gini[6502]: output file pathname: 
data/gempak/nexrad/NERCOMP_GINI/1km/n0r/n0r_20050313_2333
Mar 13 23:22:46 pngg2gini[6502]: unPNG::  1084716  14208533  13.0989
Mar 13 23:22:46 pngg2gini[6502]: Exiting

Mar 13 23:22:46 pngg2gini[6504]: Starting Up
Mar 13 23:22:46 pngg2gini[6504]: output file pathname: 
data/gempak/nexrad/NERCOMP_GINI/2km/n1p/n1p_20050313_2334
Mar 13 23:22:46 pngg2gini[6504]: unPNG::    69405   3552533  51.1855
Mar 13 23:22:46 pngg2gini[6504]: Exiting

Mar 13 23:22:46 pngg2gini[6522]: Starting Up
Mar 13 23:22:46 pngg2gini[6522]: output file pathname: 
data/gempak/nexrad/NERCOMP_GINI/4km/ntp/ntp_20050313_2335
Mar 13 23:22:46 pngg2gini[6522]: unPNG::    26162    888533  33.9627
Mar 13 23:22:46 pngg2gini[6522]: Exiting

Each invocation shows the correct sequence of log messages:

- starting up
- pathname of output file
- expansion factor: broadcast size versus size on disk (to show how well the
  product was compressed)

It looks to me like the decoding is working fine.  Can you display the
N1P and NTP images in McIDAS?  I suspect that your IMGREMAP of the
N1P and NTP products is not quite correct.

>Another question, could you briefly describe how the FNEXRAD sites are
>selected by floater team at Millersville and DuPage

The floater site is currently chosen by folks who are looking at the weather
and deciding on an area that looks interesting.  The floater process will
be changing, however, to an automated one where an objective analysis is
performed on model precipitation data to determine where the most active
area is likely to be.

>and how do you do the data fusion?

Steve Chiswell wrote a routine using GEMPAK that composites output from
stations that are reporting the particular product (N0R, N1P, or NTP)
within a half hour window ending at the time the compositer is run.
 
>Thanks a lot!

No worries.  Again, I suspect that your remapping of the N1P/NTP products
is not quite correct.

Tom
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