i.tape.spot(1)	       Grass User's Manual	   i.tape.spot(1)



NNAAMMEE
       ii..ttaappee..ssppoott   -	An  imagery  function  that extracts SPOT
       imagery from half-inch tape.
       _(_G_R_A_S_S _I_m_a_g_e _P_r_o_c_e_s_s_i_n_g _P_r_o_g_r_a_m_)

SSYYNNOOPPSSIISS
       ii..ttaappee..ssppoott

DDEESSCCRRIIPPTTIIOONN
       _i_._t_a_p_e_._s_p_o_t is a program that extracts SPOT  imagery  from
       9-track, half-inch tape.


       This  program  must  be run in a LOCATION_NAME with an x,y
       coordinate system (i.e., a coordinate system with  projec-
       tion  0).   For	further  information regarding this LOCA-
       TION_NAME type refer to the _i_m_a_g_e_r_y manual entry.


       The first prompt in _i_._t_a_p_e_._s_p_o_t asks the user for the tape
       device name.  Enter tape device name:

       This  is sometimes  /dev/rmt0 (for a half-inch tape having
       a density of 1600 bpi), but this varies with each machine.


       The next prompt is:


       Mount SPOT tape and  hit RETURN


IIMMAAGGEE IIDDEENNTTIIFFIICCAATTIIOONN MMEENNUU
       The  first  menu in the program asks the user for informa-
       tion about the data.

	     Please enter the following information

       TAPE IDENTIFICATION:				__

       IMAGE DESCRIPTION:				__

       TITLE FOR THE EXTRACTED CELL (RASTER) FILES:	__

       AFTER COMPLETING ALL ANSWERS, HIT <ESC> TO CONTINUE
		     (OR <Ctrl-C> TO CANCEL)

       This program automatically reads the satellite name,  tape
       product	code,  instrument  name,  interleaving indicator,
       spectral mode, preprocessing level and work  order  number
       into  the  field  for  TAPE  IDENTIFICATION.  The mission,
       path, row, scene shift, scene center date and time, orien-
       tation,	incidence, azimuth, elevation angle, and absolute
       calibration coefficients  and  offsets  are  automatically
       entered	into  the  field for IMAGE DESCRIPTION.  User can
       type in any other messages into the  two  sections  and	a
       description  as the TITLE of raster map layer.  The second
       menu is:

		       SPOT IMAGE EXTRACT
	   Please select region of the image to extract

		    start row: 0______(1-3002)
		      end row: 0______(1-3002)

		    start col: 0______(1-3166)
		      end col: 0______(1-3166)


       AFTER COMPLETING ALL ANSWERS, HIT <ESC> TO CONTINUE
		     (OR <Ctrl-C> TO CANCEL)

       The numbers in parentheses are the total  number  of  rows
       and  columns  on  the tape including zeros (filler).  This
       information  and  additional  information  can	also   be
       obtained  by  running the program _m_._e_x_a_m_i_n_e_._t_a_p_e.  _m_._e_x_a_m_-
       _i_n_e_._t_a_p_e will read any tape and provide the user with  the
       number  of  files  on  a  tape, the number of records on a
       tape, and the record lengths.  Any subset of the image  on
       the  tape  may  be extracted.  For a discussion of row and
       column extraction see the subheading enTITLEd ROW AND COL-
       UMN EXTRACTION below.


       The next menu is:

	 Please mark an x by the bands you want extracted

			     _____ 1
			     _____ 2
			     _____ 3

       AFTER COMPLETING ALL ANSWERS, HIT <ESC> TO CONTINUE
		     (OR <Ctrl-C> TO CANCEL)

       SPOT  imagery  has  three  bands, but the user may want to
       extract a subset of these bands.  See  the  subheading  in
       this entry enTITLEd ROW AND COLUMN EXTRACTION.


       The  user then is asked to enter the prefix/group name for
       the raster band files to be created.  This name will  pre-
       cede each band file extracted into GRASS.  For example, if
       two bands are extracted the following two band files  will
       result:


       _p_r_e_f_i_x_n_a_m_e_._1
       _p_r_e_f_i_x_n_a_m_e_._2


       The  specified  _p_r_e_f_i_x_n_a_m_e  will also automatically become
       the name for the imagery group file being  created.   Each
       image  or subset (i.e., each run of _i_._t_a_p_e_._s_p_o_t) should be
       given a unique prefix/group name.



       The extraction process will begin by first skipping a num-
       ber  of files which are not data or not requested, advanc-
       ing  to	the  first  band  requested,  forwarding  to  the
       requested  column,  and	then  reading  the  data.   After
       extracting the requested rows and columns from each  band,
       the  program creates support files for the raster band map
       layer.  The percent completion of the extraction  is  dis-
       played  on  the screen.	Because sometimes SPOT imagery is
       very large and is stored in multiple tape sets,	the  pro-
       gram  is  designed  to read image by pausing when the tape
       need to be changed and inform the user to mount	and  load
       next  tape.   The  number  of  tapes required to store one
       scene depends on the number of bytes  per  inch	(bpi)  in
       which the data are stored.


       The extracted band files will be listed as raster map lay-
       ers available in the current MAPSET and may  be	displayed
       using the GRASS commands _d_._d_i_s_p_l_a_y, _d_._r_a_s_t, or _i_._p_o_i_n_t_s.

RROOWW AANNDD CCOOLLUUMMNN EEXXTTRRAACCTTIIOONN
       The display options in GRASS allow the user to locate rows
       and columns on the digital image.  If enough disk space is
       available,  one	band  of an entire image or one band of a
       portion of an image known to contain the area of interest,
       can  be	extracted and displayed.  The _m_e_a_s_u_r_e_m_e_n_t_s option
       in _d_._d_i_s_p_l_a_y, or _d_._w_h_e_r_e (following use	of  _d_._r_a_s_t)  will
       echo  x	and  y coordinates to the screen.  (These coordi-
       nates will display negative  numbers  in  the  north-south
       direction,  but	ignoring the negative sign will yield the
       row number.)  See the _i_m_a_g_e_r_y  manual  entry  for  further
       explanation.


       Each  scene  of	a  SPOT image contains filler on both the
       left and right sides of the quad.  The user  may  want  to
       identify  the  row  and column numbers in order to exclude
       the filler.  This filler will otherwise be extracted  with
       the image and take up unnecessary disk space.


       If  a  photograph  of  the digital image is available, the
       rows and columns to be extracted can be determined from it
       by  associating inches with the total number of known rows
       and columns in the  scene.   For  example,  if  the  total
       length of the photograph is 12 inches, the total number of
       rows on the tape is 2000, and the northwest corner of  the
       area  of  interest  begins  2  inches  from the top of the
       photo, then: 12" / 2000 rows = 2" / x rows x = 333.333

       The northwest corner of the area of interest starts at row
       333.   The  starting row, ending row, starting column, and
       ending column can be calculated in this manner.

NNOOTTEESS
       After extracting an image from tape the geographic  region
       definition in the x,y coordinate LOCATION_NAME will be set
       based upon the extracted rows and columns from  the  tape.
       The  relationship  between  the image rows and columns and
       the coordinates of the geographic region is  discussed  in
       the _i_m_a_g_e_r_y format manual entry.


       This  program  is interactive and requires no command line
       arguments.

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       _G_R_A_S_S _T_u_t_o_r_i_a_l_: _I_m_a_g_e _P_r_o _c_e_s_s_i_n_g


       _d_._d_i_s_p_l_a_y

       _d_._r_a_s_t

       _d_._w_h_e_r_e

       _i_._g_r_o_u_p

       _i_._p_o_i_n_t_s

       _i_._t_a_p_e_._m_s_s

       _i_._t_a_p_e_._m_s_s_._h

       _i_._t_a_p_e_._o_t_h_e_r

       _i_._t_a_p_e_._t_m

       _i_m_a_g_e_r_y

       _m_._e_x_a_m_i_n_e_._t_a_p_e

AAUUTTHHOORR
       Tao Wen, University of Illinois at Urbana-Champaign

       _L_a_s_t _c_h_a_n_g_e_d_: _$_D_a_t_e_: _2_0_0_2_/_0_1_/_2_5 _0_5_:_4_5_:_3_3 _$



GRASS 5.0					   i.tape.spot(1)
