m.ll2u and i.tape.other

MAJOR at abrsle.agr.ca MAJOR at abrsle.agr.ca
Wed Sep 8 12:47:44 EDT 1993


To Cristina Seabra:

In response to your m.ll2u inquiry.  If you create a file in your 
home directory with format similar to the values below:

115:42:00E 37:48:00N
115:54:00E 37:48:00N
115:42:00E 37:36:00N
115:42:00E 37:36:00N

The next step is to run:

m.ll2u spheroid=clark66 input=points.in output=points.out

and points.out will be created in the same directory.

Our approach to imagery is to have a Location called imagery off
/usr/grass4.data and then it is rectified into another location.

Our system is set up such that we have our 8 mm and 1/2 inch tape 
drives located on our VAX cluster.  In order to get our imagery 
into a format that GRASS will accept we had to install LDIAS 
(landsat digital image analysis system) on our VAX.  GRASS would 
not read or ignore the header files.  

Our imagery comes in Canadian LOGSWG format.  So LDIAS peels off
the headers and performs a stretch on the data and tells us how
many rows and pixels we have. 

The resulting file is then copied from the VAX to our Ultrix (using dcp 
-iv) to my home directory  /usr/users/major.  I then start up 
GRASS in the imagery directory and use i.tape.other to bring in 
the image.  This can then be rectified to another mapset using 
i.points and i.rectify.  (We archive our i.points file in case we 
need to rectify the image again at a later date).

The important i.tape.other commands are as follows:
-------------------------------------------------------

GRASS 4.0 > i.tape.other
enter tape device name: /usr/users/major/bowisland.rgb
Please mount and load tape, then hit RETURN-->


Please enter the following information

TAPE IDENTIFICATION
   M10981

IMAGE DESCRIPTION
   Bow Island area acquired 31 August 1992 TM bans 3, 4, and 

TITLE FOR THE EXTRACTED CELL FILES
   BowIsland 

GENERIC TAPE EXTRACTION

tape layout

 0_       number of tape files to be skipped
 0_       number of records in the remaining files to be skipped
 
band files

 3        number of bands on the tape

data format
 _        band sequential  (BSQ)  |   mark one with an x
 x        band interleaved (BIL)  |

 0_____   if you select BSQ format and all the bands are in a 
	  single file

 3508__   length (in bytes) of the longest record on the tape

Please mark an x by the bands you want extracted

  x 1
  x 2
  x 3

select a prefix/group for the band cell files to be created
Enter 'list' for a list of existing imagery groups
Enter 'list -f' for a verbose listing
Hit RETURN to cancel request
> bowisland
<bowisland>
 


EXTRACT

please select region of the image to extract


start row: 1______
end row:   3000___

start col: 1______
end col:   3508___
 

advancing to row 1 ...
extracting ...  100%

----------------------------------------------------

Hope this is of some help.



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