i.ortho.init - Interactively creates or modifies entries in a camera initial exposure station file for

       Mike Baba,  DBA Systems, Inc.

       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 verticalphotograph 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.

       Theuseofi.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 apriori standard deviations for these parameters. During the imagery program,
       i.ortho.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 g.gui.image2target.

       The following menu is displayed:
               Please provide the following information
           INITIAL XC: Meters                __________
           INITIAL YC: Meters                __________
           INITIAL ZC: Meters                __________
           INITIAL omega (pitch) degrees:    __________
           INITIAL phi  (roll) degrees:      __________
           INITIAL kappa  (yaw) degrees:     __________
           Standard Deviation XC: Meters     __________
           Standard Deviation YC: Meters     __________
           Standard Deviation ZC: Meters     __________
           Std. Dev. omega (pitch) degrees:  __________
           Std. Dev. phi  (roll) 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 (pitch): Raising or lowering of the aircraft’s front (turning around the wings’ axis);

           •   Phi (roll): Raising or lowering of the wings (turning around the aircraft’s 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.

       If ground control points are available, the INITIAL values are iteratively corrected. This is particularl
       useful when the INITIAL values are rather rough estimates.

       The  standard  deviations for (XC,YC,ZC) are expressed in meters, and are used as apriori values for the
       standard deviations used in computation of the ortho rectification parameters. Higher values improve  the
       refinement  of the initial camera exposure. As a rule of thumb, 5% of the estimated target extents should
       be used.

       The standard deviations for (omega,phi,kappa) are expressed in degrees, and are used as apriori  values
       for  the  standard  deviations  used  in  computation of the ortho rectification parameters. As a rule of
       thumb, 2 degrees should be used.

       If Usethesevaluesatruntime?(1=yes,0=no) is set to 0, the values in this menu are not used.

       imagery, orthorectify

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

i.ortho.photo,g.gui.photo2image,g.gui.image2target,i.ortho.elev,i.ortho.camera,i.ortho.transform,i.ortho.rectify

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

       Accessed: Friday Apr 04 01:21:00 2025

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       © 2003-2025 GRASS Development Team, GRASS GIS 8.4.1 Reference Manual

GRASS 8.4.1                                                                                 i.ortho.init(1grass)

i.ortho.initi.ortho.init--helpi.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 (pitch) degrees

       phi=float
           Initial Camera Phi (roll) degrees

       kappa=float
           Initial Camera Kappa (yaw) degrees

       omega_sd=float
           Apriori Omega (pitch) standard deviation

       phi_sd=float
           Apriori Phi (roll) standard deviation

       kappa_sd=float
           Apriori Kappa (yaw) standard deviation