20020125: MCIDAS and GEMPAK: image remapping

Christian,

GEMPAK can display the GINI images in their raw format. However,
I found out from Tom that when you copy the images from the ADDE server,
it stores the data as an AREA file. The AREA file changes the projection
of the GINI as a special case of TANC rather than the general case of LCC.
GEMPAK does not recognize the TANC projection identifier, since it
uses the single LCC projection for both secant and tangent cone
projections. I will add the TANC identifier to GEMPAk 5.6.f so
that GEMPAK will recognize that type of AREA file as well.

You can view the AREA files from the Unidata/Wisconsin (MCIDAS) data
feed that you are receiving from the IDD as/is.

Steve Chiswell
Unidata User Support







>From: Christian Page <address@hidden>
>Organization: UCAR/Unidata
>Keywords: 200201252045.g0PKjPx07310

>
>Hello,
>
>  I have finally some time to try to remap goes-8 images to superimpose in
>GEMPAK to some observations.
>
>I tried what is said in the email below but it fails.
>
>I am using these commands:
>
>imglist.k RTGINI/GE4KIR FORM=EXP
>With that, I find that I must use SIZE=1280 1280
>
>Then I do:
>imgcopy.k RTGINI/GE4KIR MYDATA/IMAGES.1600 STYPE=VISR SIZE=1280 1280
>
>Then, in GEMPAK, I use (in sfmap):
>PROJ=sat
>GAREA=#45.30;-73.35;5;7
>SATFIL=/io/httpd/mcidas/data/AREA1600
>
>and I have sfparm set to some parameters and sffile to my valid surface file.
>
>I get the following error (also using gdcntr):
>[IM -6]  Invalid graphics area
>
>What is wrong? I tried many things, using SIZE=ALL (with no STYPE).
>I also tried to remap the satellite image with no success:
>imgremap.k RTGINI/GE4KIR MYDATA/IMAGES.1600 PRO=PS 43.40 79.38 RES=4 STYPE=VIS
> R SIZE=1280 1280
>
>Thanks again,
>
>Christian Page
>UQAM
>
>On Tue, 12 Jun 2001, Unidata Support wrote:
>
>> >From: Christian Page <address@hidden>
>> >Organization: Universite du Quebec a Montreal
>> >Keywords: 200106070835.f578Zop28356 McIDAS ADDE IMGCOPY IMGREMAP
>>
>> Christian,
>>
>> re: resampling images to 8-bit
>> >Ok. So, could you give me an example of this?
>> >I want to resample them to 8-bit (oversampled),
>>
>> The command to look at here is IMGCOPY.  The conversion from 2-byte to 1-byt
> e
>> data is controlled by the STYpe= keyword:
>>
>> HELP IMGCOPY
>> IMGCOPY -- Copies image data from a server
>>    IMGCOPY sdataset ddataset <keywords>
>> Parameters:
>>    sdataset | source ADDE dataset name and position; specify as
>>               alias.position or group/descriptor.position; to use default
>>               position, either enter "0" or omit .position portion
>>               (no def for alias or group/descriptor, def=0 for position)
>>    ddataset | destination ADDE dataset name and position; specify as
>>               alias.position or group/descriptor.position; only positive
>>               integers (absolute positions) or the default are valid for
>>               the position number; to use the default position, omit the
>>               .position portion (no def for alias or group/descriptor, for
>>               position def=the position following the most recent image)
>> Keywords:
>> *********************  Image Positioning Keywords  ***********************
>>
>>  ...
>>
>>    STYpe=VISR | reduces 2-byte data to 1-byte brightness data; not valid
>>                 with BAND=ALL or SIZE=ALL
>>
>>  ...
>>
>> So, let's assume you FTP the 2-byte data to your machine and then create
>> an ADDE dataset to hold it.  For sake of argument, let's call this first
>> dataset GE-2B, and it has three descriptors:
>>
>> GE-2B/VIS
>> GE-2B/IR
>> GE-2B/WV
>>
>> Now, you have already setup another dataset called MYDATA (previous email)
>> in which there is a descriptor IMAGES.  This group/descriptor set was
>> defined to include all possible images in AREA file format that are named
>> using AREA file naming conventions.  This dataset will automatically have
>> the AREA files in the Unidata McIDAS-X distribution in them.  For instance,
>> listing the information for images 9000 - 9020 should result in a list
>> that looks like (the listing migh have more):
>>
>> IMGLIST MYDATA/IMAGES.ALL
>> Image file directory listing for:MYDATA/IMAGES
>>  Pos Satellite/         Date       Time      Center   Band(s)
>>      sensor                                 Lat  Lon
>>  --- -------------  ------------  --------  ---- ---- ------------
>> 9010  TOPOGRAPHY     1 JAN 96001  00:00:00    40  105 1
>> 9011  TOPOGRAPHY     1 JAN 96001  00:00:00    45  105 1
>> 9012  TOPOGRAPHY     1 JAN 96001  00:00:00     0  100 1
>> 9013  TOPOGRAPHY     1 JAN 96001  00:00:00   -90  105 1
>> 9014  TOPOGRAPHY     1 JAN 96001  00:00:00    90  105 1
>> 9015  TOPOGRAPHY     1 JAN 96001  00:00:00     0    0 1
>> 9016  TOPOGRAPHY     1 JAN 96001  00:00:00    23   71 1
>> 9017  TOPOGRAPHY     1 JAN 96001  00:00:00    25  138 1
>> 9018  TOPOGRAPHY     1 JAN 96001  00:00:00    40   98 1
>> 9019  TOPOGRAPHY     1 JAN 96001  00:00:00    26  100 1
>> 9982  METEOSAT5     19 JAN 96019  16:00:00    26  100 8
>> 9983  METEOSAT5     19 JAN 96019  16:00:00    27   70 8
>> 9995  G-9 IMG       25 JAN 96025  19:00:00    25  138 4
>> IMGLIST: done
>>
>> The point of this diversion is that you do not want to use these dataset
>> position numbers when running IMGCOPY.
>>
>> Let's assume that you want to copy the latest image in the GE-2B/IR set
>> to MYDATA/IMAGES.2000 while reducing the data to 8-bit but keeping the
>> oversampling:
>>
>> IMGLIST GE-2B/IR FORM=EXP         <- to get # LINes and ELEments in image
>> IMGCOPY GE-2B/IR MYDATA/IMAGES.2000 STYPE=VISR SIZE=nlin nele
>>
>> where:
>>
>> nlin - number of lines in GE-2B/IR dataset element
>> nele - number of elements in GE-2B/IR dataset element
>>
>> You can not use SIZE=ALL with STYPE=VISR, this is why you have to
>> interrogate the source image to find out how many lines and elements
>> the source image has and use those numbers to specify the output image
>> "shape".
>>
>> You would repeat this step for each image you want to convert to 1-byte.
>>
>> >then I want to remap them to 2 projections:
>>
>> Remapping is accomplished using the IMGREMAP command.  For this, choose
>> a different range in positions numbers in the MYDATA/IMAGES dataset.
>> For sake of argument, let's choose 3000:
>>
>> >North Polar Stereographic projection
>> >#CLAT;CLON;DLAT;DLON
>> >#45.30;-73.35;1.5;4  (CYUL)
>>
>> You will have to play with this to get the RES correct, but the following
>> is the gist:
>>
>> IMGREMAP MYDATA/IMAGES.2000 MYDATA/IMAGES.3000 PRO=PS 45.30 73.35 RES=4 SIZE
> =ALL
>>
>> >#45.30;-73.35;5;7    (NE US)
>>
>> I'll let you play with the IMGREMAP invocations for this one.
>>
>> >Also, for METEOSAT imagery, I want to remap them to these projections:
>> >
>> >North Polar Stereographic projection
>> >#CLAT;CLON;DLAT;DLON
>> >#46.25;1.50;11.5;16  (France)
>> >#45;14;13;23         (Europe)
>>
>> I'll let you play with the IMGREMAP invocations for these.
>>
>> >Thanks a lot again for the great support...!
>>
>> You are welcome.
>>
>> Tom
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>