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