NAME¶
i.photo.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.photo.init
i.photo.init help
i.photo.init group=
name [--
verbose] [--
quiet]
Parameters:¶
- group=name
-
Name of imagery group for ortho-rectification
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.photo.init (menu 6) is only required when rectifying
a tilted or oblique aerial photo.
i.photo.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
<A HREF="i.photo.2target.html">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.camera, i.photo.2image,
i.photo.2target, i.photo.rectify
AUTHOR¶
Mike Baba, DBA Systems, Inc.
Last changed: $Date: 2010-12-22 11:05:10 +0100 (Wed, 22 Dec 2010) $
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