[Datastream #VJI-624035]: help with AXFORM ASCII

Hi Julia,

re:
> I have a question about the ASCII file converted from an area file by
> AXFORM in McIDAS. Is the ASCII date file the same as the GVAR data block
> described in

> http://www.ssec.wisc.edu/mcidas/doc/misc_doc/area2.html?

The ASCII file produced by AXFORM will output the values from the AREA
file being used.  If the AREA file's data is 1-byte, the AXFORM output
will represent 1-byte data.  If the AREA file contains 10-bit (10-bits
has to be stored in 2-bytes), the AXFORM output will represent the 10-bit
data.

> I am using
> GOES-12 visible channel. The document says GVAR data has 10-bit. But the
> ASCII file only has 8-bit.

It would seem that the AREA file you copied the data to was converted to
1-byte data during the copy.

> Here is the header file .HDR from AXFORM.
> 
> Satellite: G-12 IMG                    SSEC ID Number: 78
> Image Date: 21 FEB 07 (YYDDD=07052)    Image Start Time: 22:45:00 GMT
> IMAGE COORDINATES
> Start Line  Start Element    Line Resolution  Element Resolution
> 2425        9032               4                 8
> IMAGE FILE(S)
> Parameter   Unit Band  Lines  Elements   Element Format   Scale   File
> Name
> Header                                  ASCII
> TESTIMAGE.HDR
> Raw Sensor   none    1     480      640 Short Int (8 bit)      1
> TESTIMAGE.001
> Raw Sensor   none    1     480      640 ASCII Text (xI4)       1
> TESTIMAGE.A01
> Brightness   none    1     480      640 Short Int (8 bit)      1
> TESTIMAGE.002
> Brightness   none    1     480      640 ASCII Text (xI4)       1
> TESTIMAGE.A02
> Latitude       NA         480     640   Integer (16 bit)     100
> TESTIMAGE.LAT
> Longitude      NA         480     640   Integer (16 bit)     100
> TESTIMAGE.LON
> Latitude       NA         480     640   ASCII Text (xI7)     100
> TESTIMAGE.ALT
> Longitude      NA         480     640   ASCII Text (xI7)     100
> TESTIMAGE.ALN
> 
> Can anyone explain the difference between 8-bit ASCII and 10-bit GVAR?
> Thank you.

See above.


Cheers,

Tom
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Ticket Details
===================
Ticket ID: VJI-624035
Department: Support McIDAS
Priority: Normal
Status: Closed