NAME

       i.ortho.init   -  Interactively creates or modifies entries in a camera initial exposure station file for
       imagery group referenced by a sub-block.

KEYWORDS

       imagery, orthorectify

SYNOPSIS

       i.ortho.init
       i.ortho.init --help
       i.ortho.init [-rp]  group=name   [xc=float]    [yc=float]    [zc=float]    [xc_sd=float]    [yc_sd=float]
       [zc_sd=float]     [omega=float]     [phi=float]     [kappa=float]     [omega_sd=float]     [phi_sd=float]
       [kappa_sd=float]   [--help]  [--verbose]  [--quiet]  [--ui]

   Flags:
       -r
           Use initial values at run time

       -p
           Print initial values

       --help
           Print usage summary

       --verbose
           Verbose module output

       --quiet
           Quiet module output

       --ui
           Force launching GUI dialog

   Parameters:
       group=name [required]
           Name of imagery group for ortho-rectification

       xc=float
           Initial Camera Exposure X-coordinate

       yc=float
           Initial Camera Exposure Y-coordinate

       zc=float
           Initial Camera Exposure Z-coordinate

       xc_sd=float
           Apriori X-coordinate standard deviation

       yc_sd=float
           Apriori Y-coordinate standard deviation

       zc_sd=float
           Apriori Z-coordinate standard deviation

       omega=float
           Initial Camera Omega (roll) degrees

       phi=float
           Initial Camera Phi (pitch) degrees

       kappa=float
           Initial Camera Kappa (yaw) degrees

       omega_sd=float
           Apriori Omega (roll) standard deviation

       phi_sd=float
           Apriori Phi (pitch) standard deviation

       kappa_sd=float
           Apriori Kappa (yaw) standard deviation

DESCRIPTION

       Aerial photographs may be either vertical or oblique. Vertical photographs can be truly vertical (nadir),
       or slightly tilted (less than 3 degree from the vertical). Usually  aerial  photos  are  tilted  to  some
       degree. We refer to the term vertical photograph up to a tilt of 3 degree.
       Oblique  aerial  photographs  are  purposely  taken  with an angle between 3 and 90 degree from the nadir
       direction.

       The use of i.ortho.init (menu 6) is only required when rectifying a tilted or oblique aerial photo.

       i.ortho.init creates or modifies entries in a camera initial exposure  station  file  for  imagery  group
       referenced  by  a  sub-block.   These  entries  include:  the  (XC,YC,ZC) standard (e.g. UTM) approximate
       coordinates of the camera exposure station; initial roll, pitch, and  yaw  angles  (in  degrees)  of  the
       cameras  attitude; and the a priori standard deviations for these parameters. During the imagery program,
       i.photo.rectify,  the  initial  camera  exposure  station  file  is   used   for   computation   of   the
       ortho-rectification parameters.  If no initial camera exposure station file exist, the default values are
       computed from the control points file created in i.photo.2target.

       The following menu is displayed:
               Please provide the following information
            INITIAL XC: Meters                __________
            INITIAL YC: Meters                __________
            INITIAL ZC: Meters                __________
            INITIAL omega (roll) degrees:     __________
            INITIAL phi  (pitch) degrees:     __________
            INITIAL kappa  (yaw) degrees:     __________
            Standard Deviation XC: Meters     __________
            Standard Deviation YC: Meters     __________
            Standard Deviation ZC: Meters     __________
            Std. Dev. omega (roll) degrees:   __________
            Std. Dev. phi  (pitch) degrees:   __________
            Std. Dev. kappa  (yaw) degrees:   __________
               Use these values at run time? (1=yes, 0=no)
            AFTER COMPLETING ALL ANSWERS, HIT <ESC> TO CONTINUE
                         (OR <Ctrl-C> TO CANCEL)

       The  INITIAL  values  for  (XC,YC,ZC)  are expressed in standard (e.g. UTM) coordinates, and represent an
       approximation for the location of the camera at the time of exposure.

           •   X: East aircraft position;

           •   Y: North aircraft position;

           •   Z: Flight altitude above sea level

       The INITIAL values for (omega,phi,kappa) are expressed in degrees, and represent an approximation for the
       cameras attitude  at the time of exposure.

           •   Omega (roll): Raising or lowering of the wings (turning around the aircraft’s axis);

           •   Phi (pitch): Raising or lowering of the aircraft’s front (turning around the wings’ axis);

           •   Kappa (yaw): Rotation needed to align the aerial photo to true north: needs to be denoted as  +90
               degree for clockwise turn and -90 degree for a counterclockwise turn.

       The  standard  deviations for (XC,YC,ZC) are expressed in meters, and are used as a priori values for the
       standard deviations used in computation of the ortho rectification parameters.

       The standard deviations for (omega,phi,kappa) are expressed in degrees, and are used as a  priori  values
       for the standard deviations used in computation of the ortho rectification parameters.

       If Use these values at run time? (1=yes, 0=no) is set to 0, the values in this menu are not used.

SEE ALSO

          i.ortho.photo,   i.photo.2image,  i.photo.2target,  i.ortho.elev,  i.ortho.camera,  i.ortho.transform,
       i.photo.rectify

AUTHOR

       Mike Baba,  DBA Systems, Inc.

       Last changed: $Date: 2017-01-14 16:23:42 +0100 (Sat, 14 Jan 2017) $

SOURCE CODE

       Available at: i.ortho.init source code (history)

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       © 2003-2018 GRASS Development Team, GRASS GIS 7.4.0 Reference Manual

GRASS 7.4.0                                                                                 i.ortho.init(1grass)