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20021004: BAR command and using a stretch on a remapped NEXRCOMP image

>From: "Paul L. Sirvatka" <address@hidden>
>Organization: College of DuPage
>Keywords: 200210041733.g94HXZ106826 McIDAS NEXRCOMP BAR IMGREMAP IMGCHA

Paul,

>The Bar command should have a range? What does that mean?

RAN= should specify the range of display values represented in the data
bar.  I see by your comment below that it doesn't.  This looks like a
bug.

>I took the nexrad composite and SU'd everything out of it so it just shows
>5 to 75dbZ's. I created a nice looking color table (EU) to go with it. I
>wanted the Bar to show correctly but it still outlines 0 to 80 dbZ. Even
>when I plotted 55 to 75 range, it still showed eveything. In other words
>the keywords RAN did nothing I could see.

>Also...shouldn't the bar plot *over* the maps?

The color portion of the BAR is drawn in the image plane; the annotation
portion of the BAR is drawn in the graphics plane.  Since all graphics
will be on top of displayed image values, the map lines can/will go
through the data bar.  You can control this by blanking out the rectangle
in which the data bar will be drawn before running BAR.  Check out the
CW command.  You will need to play with it to get the blanking box sized
the way you want it (use the PC command to position the cursor and then
run the CW command).

>The maps plot through the bar which makes things look a bit weird!

I guess that this never bothered me.  Different eyes, different
perspective :-)

>Thanks for the help.

No worries.

>From address@hidden Fri Oct  4 13:05:04 2002

>As long as I am asking questions:

>I am trying to display these NEXRAD composites in the smae projection as
>my satellite images. I have used imgremap to accomplish this. BUT...

OK.  Another cute thing you can do is "overlay" the radar echos from
the NEXRAD image on top of a satellite image.  You do this using
the new, experimental FRMOLAY command.

Here is one example:

IMGDISP RTIMAGES/GE-IR LATLON=39 83 PLACE=C MAG=2 2 EU=IMAGE SU=X ALL=11 SF=YES 
REFRESH='EG GRA=(GRA);MAP FILE=OUTLUSAM MCOL=1 WID=1 GRA=(GRA);BAR (GRA) 
SU=IRTEMP X COL=7 ORIENT=VER'

FRMOLAY NEXRCOMP/1KN0R-NAT UNIT=BRIT 
RAN='3:85,86:96,97:107,108:119,120:130,131:141,142:153,154:164,165:175,176:187,188:198,199:209,210:221,222:232,233:243,244:255'
 INT=0 GU=RADAR16_32

An example of this can be seen at:

http://www.unidata.ucar.edu/staff/tom/gifs/nexrolay.gif

The nice thing about displaying the radar echos in the graphics plane
is that they can be toggled off and on (using the ALT-W toggle) or any
display level used in the radar overlay can be turned off and on
individually (using the 'GU OFF level bframe eframe' and 'GU ON level
bframe eframe' command sequences).

To get a feeling for this, do the load as I indicated above (you have
to be running McIDAS-X v2002 to get the FRMOLAY command and the
RADAR16_32 graphics palette AND you have to be running a session that
supports 32 graphics levels).

After getting the image loaded and radar echos displayed on top of the
image, then use the ALT-W toggle to turn all graphics off and on (hold
down the ALT key while pressing the W key).

With all graphics display levels on, try turning off selected levels:

GU OFF 32
GU OFF 31
GU OFF 30
GU OFF 29
GU OFF 28
GU OFF 27
 ...

Then turn them back on:

GU ON 32
GU ON 31
GU ON 30
GU ON 29
GU ON 28
GU ON 27
 ...

By putting the GU OFFs and GU ONs into a script, you could have various
levels flash off and on.

>I have used the stretch utility to get just the 5-75 dbZ levels (as
>stated in a previous question.) But if I copy this image to a satellite
>darea to get the same projection, i lose the ability to use the SU since
>it is now the wrong type. I hope this is clear. I do not know my way
>around this problem.

At this point, you can either create a stretch table for the remapped
image (using the type that it is in), or you can use the IMGCHA command
to change the SS (Sensor Source) of the destination to make it what
it was originally.

Here is an example:

IMGCOPY RTIMAGES/GE-IR MYDATA/IMAGES.1234 SIZE=ALL
IMGLIST MYDATA/IMAGES.1234 FORM=EXP
Image file directory listing for:MYDATA/IMAGES
 Pos Satellite/         Date       Time      Center      Res (km)   Image_Size
     sensor                                 Lat  Lon    Lat   Lon
 --- -------------  ------------  --------  ---- ----  ----- ----- ------------
1234  G-8 IMG        4 OCT 02277  19:15:00    23   71
    Band: 4  10.7 um Surface temp; longwave window      4.59  4.67  1400 x 1728
     proj:    0 created: 2002277 195210  memo: RT GVAR
     type:VISR     cal type:BRIT
     offsets:  data=    2816 navigation=  256 calibration=    0 auxillary=    0
     doc length:   0   cal length:   0   lev length:   0 PREFIX=   0
     valcod:          0 zcor:  0 avg-smp: N
     start yyddd: 2002277  start time:191515  start scan:  401
     lcor: 2785  ecor:  9141  bytes per pixel: 1  ss: 70
     Resolution Factors (base=1):   Line=    4.0   Element=    8.0
IMGLIST: done

IMGREMAP NEXRCOMP/1KN0R-NAT MYDATA/IMAGES.1234 SSIZE=ALL
IMGLIST NEXRCOMP/1KN0R-NAT FORM=EXP
Image file directory listing for:NEXRCOMP/1KN0R-NAT
 Pos Satellite/         Date       Time      Center      Res (km)   Image_Size
     sensor                                 Lat  Lon    Lat   Lon
 --- -------------  ------------  --------  ---- ----  ----- ----- ------------
 362  RADAR          4 OCT 02277  19:42:00     TWX
    Band: 27 No Information Available                   1.02  1.02  3000 x 4736
     proj:    0 created: 2002277 195326  memo: 1 km CONUS N0R Composite [dBZ]
     type:NEXR     cal type:RAW
     offsets:  data=    1024 navigation=  256 calibration=    0 auxillary=  768
     doc length:   0   cal length:   0   lev length:   0 PREFIX=   0
     valcod:          0 zcor:  0 avg-smp: N
     start yyddd: 2002277  start time:194200  start scan:    0
     lcor:    1  ecor:     1  bytes per pixel: 1  ss:  7
     Resolution Factors (base=1):   Line=    1.0   Element=    1.0
IMGLIST: done

IMGCHA MYDATA/IMAGES.1234 BAND=27 SS=7

     Directory Block Changes
Changed Band Sequence from: 4  to: 27
Changed Sensor Source from: 70  to: 7
Transferring AREA data outbound, bytes= 736

Image file directory listing for:MYDATA/IMAGES
 Pos Satellite/         Date       Time      Center      Res (km)   Image_Size
     sensor                                 Lat  Lon    Lat   Lon
 --- -------------  ------------  --------  ---- ----  ----- ----- ------------
1234  RADAR          4 OCT 02277  19:15:00     
    Band: 27 No Information Available                   4.59  4.67  1400 x 1728
     proj:    0 created: 2002277 195314  memo: RT GVAR
     type:VISR     cal type:BRIT
     offsets:  data=    2816 navigation=  256 calibration=    0 auxillary=    0
     doc length:   0   cal length:   0   lev length:   0 PREFIX=   0
     valcod:          0 zcor:  0 avg-smp: N
     start yyddd: 2002277  start time:191515  start scan:  401
     lcor: 2785  ecor:  9141  bytes per pixel: 1  ss:  7
     Resolution Factors (base=1):   Line=    5.0   Element=    5.0
IMGLIST: done

IMGCHA: Done ...

I hope that this helps...

Tom