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



NNAAMMEE
       ii..ttaappee..ttmm   -  An  imagery  function that extracts LANDSAT
       Thematic Mapper (TM) 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..ttmm

DDEESSCCRRIIPPTTIIOONN
       _i_._t_a_p_e_._t_m is a program that extracts LANDSAT Thematic Map-
       per (TM) imagery from half-inch tape.


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


       The first prompt in _i_._t_a_p_e_._t_m asks the user for	the  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:

       Please mount and load tape, then 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 Raster (Cell) Files:	__

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

       This program automatically enters the scene ID number into
       the  field  for	Tape  Identification.  The mission, path,
       row, quadrant, date, and whether the image is corrected is
       automatically  entered  into  the field for Image Descrip-
       tion.


       The second menu is:

		     THEMATIC MAPPER EXTRACT
       please select the desired tape window (geographic
       region definition) to extract

		    first row: _______(1-2984)
		    last row: _______(1-2984)

		    first col: _______(1-4220)
		    last col: _______(1-4220)


       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 lengthes.  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 make an x by the bands you want extracted

			     _____ 1
			     _____ 2
			     _____ 3
			     _____ 4
			     _____ 5
			     _____ 6
			     _____ 7

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

       TM  imagery  has 7 bands, but the user may want to extract
       only 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 for the
       raster band files to be created.  This name  will  precede
       each  band  file  extracted  into  GRASS.  For example, if
       three bands are extracted the following three  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
       _p_r_e_f_i_x_n_a_m_e_._3


       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  quad	(i.e.,	each  run of _i_._t_a_p_e_._t_m) should be
       given a unique prefix/group name.


       The extraction process will begin by  first  skipping  the
       number  of  specified  files,  advancing to the first band
       requested, and then reading the	tape.	After  extracting
       the  requested rows and columns for each band, the program
       creates support files for the raster band map layer.   The
       percent	completion  of the extraction is displayed on the
       screen.	Because TM imagery is divided into four quads and
       is  stored  in multiple tape sets, the program is designed
       to read one quad at a time.  The number of tapes  required
       to  store one quad depends on the number of bytes per inch
       in which the data is stored.  If more  than  one  tape  is
       required  to  store  one  quad, the program will pause and
       inform the user to mount the next tape.


       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.

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 manual entry.


       This  program  is interactive and requires no command line
       arguments.

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 quad of a TM image contains filler on both	the  left
       and  right  sides of the quad.  The user may want to iden-
       tify 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.

SSEEEE AALLSSOO
       _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_m_a_g_e_r_y

       _m_._e_x_a_m_i_n_e_._t_a_p_e

AAUUTTHHOORR
       Michael	 Shapiro,   U.S.Army   Construction   Engineering
       Research Laboratory

       _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.tm(1)
