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19990119: Query about satellite/model output overlay

James,

The only drivers that support radar/satellite imagery are the xw and
gf drivers. The nc and ps driver are not capable of displaying
images (proj=sat/rad). The image portion of the display is only 
possible from the X server (which the xw and gf drivers use).

You can overlay the data using Garp, which of course isn't pregenerated
like the meta files. If you want to create a pregenerated loop
of model overlays on satellite images, you could use the gf driver
and then a package such as ImageMagick to create an animated
gif viewable in a web browser, or one of the java applets
that are widely available.

The projection of all images (radar and satellite) are those
which the image is defined on. GEMPAK is not capable of
reprojecting from satellite or the different radar projections
into another projection. Instead, all overlays in gempak
are onto the proj=sat/rad. Unfortunately, the Mercator
projection of the 2km mosaic is what is being created by WSI.


Steve Chiswell
Unidata User Support



>From: address@hidden (James Murakami)
>Organization: .
>Keywords: 199901192319.QAA28171

>Hi:
>
>I occasionally overlay model output (ETA,NGM,AVN) over satellite
>imagery using GDPLOT (GDCNTR limits you to one variable).
>I tried rewriting a copy of a "eta script"(Used for displaying
>various ETA model output on Ntrans) to display satellite imagery
>in the background. It seemed like a simple enough task...wrong.
>While I get surface isobars and 1000-500mb thickness (for example)
>in a satellite projection, no GOES imagery is displayed. I tried
>looking at the Meta file in Ntrans (contours viewable) and Nsat
>(nothing viewable). Can you help me or is this request impossible
>with the current Ntrans/Nsat system?
>
>I include a portion of my script below just in case the task can
>be done.
>
>Oh, one other thing.
>I've noticed that viewing coarser resolution WSI radar mosaics
>appear in polar sterographic projection on Nsat. It appears in
>mercator (cylindrical?) projection with the higher resolution
>mosaic data (I'm viewing the whole contiguous U.S.). Aesthetically
>speaking (personally), I like a sterographic projection over
>mercator. What file needs changing to display both types of
>radar in sterographic projection?
>
>Sincerely,
>
>James Murakami
>
>Staff Meteorologist/Student Affairs
>Department of Atmospheric Sciences
>University of California, Los Angeles
>405 Hilgard Ave.
>Los Angeles, CA  90095-1565
>
>
>   e-mail:  address@hidden
>telephone:  310-825-2418
>      Fax:  310-206-5219
>=================================================================
># source the 5.4 environment variables
>#
>source /unidata/ldm/gempak/Gemenviron
>#
># Set the root Ntrans directory
>#
>setenv NTRANSHOME  $NAWIPS/nprogs/ntrans2.1
>#
># cd to temporary directory. This is where the Nmeta file
># will be kept while the script is running.
>#
>cd /gempak2/ntrans/tenki
>#
># Define current date
>#
>set yy=`date -u +%y`
>set mm=`date -u +%m`
>set dd=`date -u +%d`
>set date=${yy}${mm}${dd}
>#
># Set up local variables
>#
># SAT_DIR=GOES imagery directory
># DATA_DIR=GEMPAK gridded data directory;
># META_DIR=Directory to store Meta files in
># LOGFILE=file to catch GEMPAK program output
>#
>setenv DATA_DIR /gempak/data/hrs
>setenv SAT_DIR  /gempak/data/sat
>setenv META_DIR /gempak2/ntrans/tenki
>setenv LOGFILE  /scra5/tenki/eta/eta.log
>#
># Remove last hour's log file
>#
>/bin/rm -f $LOGFILE
>#
># Remove earlier version file
>#
>rm -f /gempak2/ntrans/tenki/etasat_${date}_${1}
>#
># Set some variables for GDPLOT run
># Plots GOES-10 infrared imagery but can be changed in
># the "set" line below.
>#
>set device=nc
>set grid=${DATA_DIR}/${date}${1}_eta.gem
>set sat=${SAT_DIR}/${date}${1}00_g10ir.are
>#
># Run GDPLOT and generate satellite/ETA model Meta file
>#
>$GEMEXE/gdplot << EOF >> $LOGFILE
>\$RESPOND = YES
>GDFILE  = $grid
>GDATTIM = f00
>DEVICE  = $device | $META_DIR/etasat_${date}_${1}
>SATFIL  = $sat
>PANEL   = 0
>TEXT    = 1/21//hw
>CONTUR  = 1
>MAP     = 17//2
>CLEAR   = yes
>CLRBAR  = 1
>GAREA   = 28;-145;60;-86
>PROJ    = sat
>LATLON  = 0
>GFUNC  =sub(hght@500,hght@1000)!sm5s(emsl)
>GLEVEL = 500:1000            !0  
>GVCORD = pres                !none
>WIND   = !                   !   
>PANEL  = 0
>SKIP   = 0                   !0  
>SCALE  = -1                  !0  
>CTYPE  = c
>CINT   = 6                   !4  
>LINE   = 2/3/2               !30//3
>FINT   =
>FLINE  =
>HILO   =                     ! 25;1/H#;L#///30;30/y
>HLSYM  = 2;1.5//21//hw
>CLRBAR =
>GVECT  =
>REFVEC =
>CLEAR  = yes
>TITLE   = 5/-2/  ~  ETA SFC PRESSURE,1000-500 MB THICKNESS|^ MSLP, 1000-500 TH
> KNlist
>run
>
>exit
>EOF
># Run GPEND to clean up
>#
>$GEMEXE/gpend
>rm -f /gempak2/ntrans/tenki/*.nts
>==============================================================================
> =
>