Provided by: grass-doc_8.3.0-1_all bug

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 (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

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 (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 a priori
       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  a
       priori  values  for the standard deviations used in computation of the ortho rectification
       parameters. As a rule of thumb, 2 degrees should be used.

       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.

SOURCE CODE

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

       Accessed: Tuesday Jun 27 11:14:21 2023

       Main index | Imagery index | Topics index | Keywords index | Graphical index | Full index

       © 2003-2023 GRASS Development Team, GRASS GIS 8.3.0 Reference Manual