i.ortho.init(1)

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 7.4.2 Reference Manual