[McIDAS #QFU-969979]: Retaining calibrated units after imgremap

Hi Greg,

re:
> I'm working with the GOES-10 data in McIDAS and I'm trying to
> remap the imagery to specific sector with the goal of generating a
> netCDF file for that sector.

OK.

> I'm starting with each band in a separate
> AREA file and running and IMGREMAP to get the sector I want. Here's an
> IMGLIST of the source file I'm using for the IMGREMAP:
> 
> xtuser@ingest:/satellite/mcidas> imglist.k MYDATA/IMAGES.1051 FORM=ALL
> Image file directory listing for:MYDATA/IMAGES
> Pos Satellite/         Date       Time      Center      Res (km)
> Image_Size
> sensor                                 Lat  Lon    Lat   Lon
> --- -------------  ------------  --------  ---- ----  ----- ----- ------------
> 1051  G-10 IMG       4 SEP 08248  15:28:00   -19   62
> Band: 1    0.65 um VIS Cloud and Surface Features    1.10  0.58 6868 x13136
> proj:    0 created: 2008248 160429  memo: RT GVAR
> type:GVAR     cal type:RAW
> offsets:  data=    3328 navigation=  256 calibration= 2816 auxiliary=    0
> doc length: 228   cal length:   0   lev length:   0 PREFIX= 232
> valcod:  248152800 zcor:  0 avg-smp: N
> start yyddd: 2008248  start time:152809  start scan:  818
> lcor: 6541  ecor:  8293  bytes per pixel: 2  ss: 74
> Resolution Factors (base=1):   Line=    1.0   Element=    1.0
> imglist.k: done
> 
> I ran the follwing IMGREMAP command:
> 
> imgremap.k MYDATA/IMAGES.1051 MYDATA/IMAGES.1061 TIME=15:28:00
> LATLON=-17.5 82.5 PRO=RECT RES=1 SIZE=3000 3000 SSIZE=ALL
> 
> After the IMGREMAP I get:
> 
> xtuser@ingest:/satellite/mcidas> imglist.k MYDATA/IMAGES.1061 FORM=ALL
> Image file directory listing for:MYDATA/IMAGES
> Pos Satellite/         Date       Time      Center      Res (km)
> Image_Size
> sensor                                 Lat  Lon    Lat   Lon
> --- -------------  ------------  --------  ---- ----  ----- ----- ------------
> 1061  G-10 IMG       4 SEP 08248  15:28:00   -18   82
> Band: 1    0.65 um VIS Cloud and Surface Features    1.00  0.95 3000 x 3000
> proj:    0 created: 2008248 171702  memo: RT GVAR
> type:VISR     cal type:BRIT
> offsets:  data=     768 navigation=  256 calibration=    0 auxiliary=    0
> doc length:   0   cal length:   0   lev length:   0 PREFIX=   0
> valcod:          0 zcor:  0 avg-smp: N
> start yyddd: 2008248  start time:152809  start scan:  818
> lcor: 8501  ecor:  8501  bytes per pixel: 1  ss: 74
> Resolution Factors (base=1):   Line=    1.0   Element=    1.0
> imglist.k: done

NB: IMGREMAP's output is always 1=byte imagery.

> My question is How do I get the units to be %Albedo in the remapped
> file, not brightness?

The BRITness will always be there after an IMGREMAP because it will reduce
a 2-byte image to a 1-byte image.  This issue has come up at multiple MUG
meetings.

> IMGPROBE showed these were available in the
> original file but I didn't see any command line options in IMGREMAP to
> retain these units.

Right.

> I feel like I'm missing a step but I don't know
> what it is. Can you point me in the right direction?

I think your only options are:

- use the McIDAS-XRD routine REMAP2 to do the remap

- add a calibration for Albedo to the resultant image

I would think that the best approach would be to use REMAP2:

- create the REMAP2 executables and HELP files:

<as 'mcidas'>
cd ~/mcidas2008/src    <- or ~/mcidas2007/src if you havn't upgraded yet
make remap2.k remap2.hlp
ln remap2.k ~/bin
ln remap2.hlp ~/help

The help available for REMAP2 is short and seemingly not comprehensive:

HELP REMAP2
REMAP2 -- Remaps a 2-byte area into a different projection
  REMAP2 sarea darea spline <keywords>
Parameters:
  sarea | source area number to remap
  darea | destination area number for remapped image; darea
          contains the projection that sarea is remapped into
  spline | spline function, area pixels (def=20)
Keywords:
  BAND= | list of band numbers (def=all bands)
  MERGE=YES | merge data in sarea with what is in darea
       =NO  | overwrite data in darea (def)
  SMOOTH=limb data
         limb  | NO/YES for limb smoothing (def=NO)
         data  | NO/YES for data smoothing (def=NO)
Remarks:
  The sarea and darea must contain navigation before you can remap
  images. REMAP2 does not work with POES data.
----------

One thing that should jump out at you immediately is that REMAP2 is _NOT_
an ADDE application.  You will need to specify the AREA file number of
the single band input file AND the AREA number for the output file.

> I haven't tried
> the IR an WV channels yet but I'm expecting to have a similar problem
> with those.

Actually, you should not have a problem with the infrared channels if
your objective is to get temperatures as the IMGREMAP remapped image will
be calibrated so you will be able to get temperature values using IMGPROBE
interrogations.  If you are looking for radiance, however, you will need
to go through the REMAP2 route.

Cheers,

Tom
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Ticket Details
===================
Ticket ID: QFU-969979
Department: Support McIDAS
Priority: Normal
Status: Closed