1photo.init(1) Grass User's Manual photo.init(1)
2
6 photo.init
7
9 Aerial photographs may be either vertical or oblique. Vertical photo‐
10 graphs can be truly vertical (nadir), or slightly tilted (less than 3
11 degree from the vertical). Usually aerial photos are tilted to some
12 degree. We refer to the term vertical photograph up to a tilt of 3
13 degree.
14 Oblique aerial photographs are purposely taken with an angle between 3
15 and 90 degree from the nadir direction.
16 The use of photo.init (menu 6) is only required when rectifying a
18 tilted or oblique aerial photo.
19 photo.init creates or modifies entries in a camera initial exposure
21 station file for imagery group referenced by a sub-block. These
22 entries include: the (XC,YC,ZC) standard (e.g. UTM) approximate coordi‐
23 nates of the camera exposure station; initial roll, pitch, and yaw
24 angles (in degrees) of the cameras attitude; and the a priori standard
25 deviations for these parameters. During the imagery program, photo.rec‐
26 tify, the initial camera exposure station file is used for computation
27 of the ortho-rectification parameters. If no initial camera exposure
28 station file exist, the default values are computed from the control
29 points file created in <A HREF="photo.2target.html">photo.2target.
30 The following menu is displayed:
32 Please provide the following information
33 INITIAL XC: Meters __________
34 INITIAL YC: Meters __________
35 INITIAL ZC: Meters __________
36 INITIAL omega (roll) degrees: __________
37 INITIAL phi (pitch) degrees: __________
38 INITIAL kappa (yaw) degrees: __________
39 Standard Deviation XC: Meters __________
40 Standard Deviation YC: Meters __________
41 Standard Deviation ZC: Meters __________
42 Std. Dev. omega (roll) degrees: __________
43 Std. Dev. phi (pitch) degrees: __________
44 Std. Dev. kappa (yaw) degrees: __________
45 Use these values at run time? (1=yes, 0=no)
46 AFTER COMPLETING ALL ANSWERS, HIT <ESC> TO CONTINUE
47 (OR <Ctrl-C> TO CANCEL)
48 The INITIAL values for (XC,YC,ZC) are expressed in standard (e.g. UTM)
51 coordinates, and represent an approximation for the location of the
52 camera at the time of exposure.
53 X: East aircraft position;
55 Y: North aircraft position;
57 Z: Flight altitude above sea level
59 The INITIAL values for (omega,phi,kappa) are expressed in degrees, and
61 represent an approximation for the cameras attitude at the time of
62 exposure.
63 Omega (roll): Raising or lowering of the wings (turning
65 around the aircraft's axis);
66 Phi (pitch): Raising or lowering of the aircraft's front
68 (turning around the wings' axis);
69 Kappa (yaw): Rotation needed to align the aerial photo
71 to true north: needs to be denoted as +90 degree for
72 clockwise turn and -90 degree for a counterclockwise
73 turn.
74 The standard deviations for (XC,YC,ZC) are expressed in meters, and are
76 used as a priori values for the standard deviations used in computation
77 of the ortho rectification parameters.
78 The standard deviations for (omega,phi,kappa) are expressed in degrees,
80 and are used as a priori values for the standard deviations used in
81 computation of the ortho rectification parameters.
82 If Use these values at run time? (1=yes, 0=no) is set to 0, the values
84 in this menu are not used.
85
87 i.ortho.photo, photo.camera, photo.2image, photo.2target, photo.rectify
88
90 Mike Baba, DBA Systems, Inc.
91 Last changed: $Date: 2005/11/15 08:14:53 $
93GRASS 6.2.2 photo.init(1)