1i.ortho.init(1) GRASS GIS User's Manual i.ortho.init(1)
2
6 i.ortho.init - Interactively creates or modifies entries in a camera
7 initial exposure station file for imagery group referenced by a
8 sub-block.
9
11 imagery, orthorectify
12
14 i.ortho.init
15 i.ortho.init --help
16 i.ortho.init [-rp] group=name [xc=float] [yc=float] [zc=float]
17 [xc_sd=float] [yc_sd=float] [zc_sd=float] [omega=float]
18 [phi=float] [kappa=float] [omega_sd=float] [phi_sd=float]
19 [kappa_sd=float] [--help] [--verbose] [--quiet] [--ui]
20 Flags:
22 -r
23 Use initial values at run time
24 -p
26 Print initial values
27 --help
29 Print usage summary
30 --verbose
32 Verbose module output
33 --quiet
35 Quiet module output
36 --ui
38 Force launching GUI dialog
39 Parameters:
41 group=name [required]
42 Name of imagery group for ortho-rectification
43 xc=float
45 Initial Camera Exposure X-coordinate
46 yc=float
48 Initial Camera Exposure Y-coordinate
49 zc=float
51 Initial Camera Exposure Z-coordinate
52 xc_sd=float
54 Apriori X-coordinate standard deviation
55 yc_sd=float
57 Apriori Y-coordinate standard deviation
58 zc_sd=float
60 Apriori Z-coordinate standard deviation
61 omega=float
63 Initial Camera Omega (pitch) degrees
64 phi=float
66 Initial Camera Phi (roll) degrees
67 kappa=float
69 Initial Camera Kappa (yaw) degrees
70 omega_sd=float
72 Apriori Omega (pitch) standard deviation
73 phi_sd=float
75 Apriori Phi (roll) standard deviation
76 kappa_sd=float
78 Apriori Kappa (yaw) standard deviation
79
81 Aerial photographs may be either vertical or oblique. Vertical photo‐
82 graphs can be truly vertical (nadir), or slightly tilted (less than 3
83 degree from the vertical). Usually aerial photos are tilted to some de‐
84 gree. We refer to the term vertical photograph up to a tilt of 3 de‐
85 gree.
86 Oblique aerial photographs are purposely taken with an angle between 3
87 and 90 degree from the nadir direction.
88 The use of i.ortho.init (menu 6) is only required when rectifying a
90 tilted or oblique aerial photo.
91 i.ortho.init creates or modifies entries in a camera initial exposure
93 station file for imagery group referenced by a sub-block. These en‐
94 tries include: the (XC,YC,ZC) standard (e.g. UTM) approximate coordi‐
95 nates of the camera exposure station; initial roll, pitch, and yaw an‐
96 gles (in degrees) of the cameras attitude; and the a priori standard
97 deviations for these parameters. During the imagery program,
98 i.photo.rectify, the initial camera exposure station file is used for
99 computation of the ortho-rectification parameters. If no initial cam‐
100 era exposure station file exist, the default values are computed from
101 the control points file created in i.photo.2target.
102 The following menu is displayed:
104 Please provide the following information
105 INITIAL XC: Meters __________
106 INITIAL YC: Meters __________
107 INITIAL ZC: Meters __________
108 INITIAL omega (pitch) degrees: __________
109 INITIAL phi (roll) degrees: __________
110 INITIAL kappa (yaw) degrees: __________
111 Standard Deviation XC: Meters __________
112 Standard Deviation YC: Meters __________
113 Standard Deviation ZC: Meters __________
114 Std. Dev. omega (pitch) degrees: __________
115 Std. Dev. phi (roll) degrees: __________
116 Std. Dev. kappa (yaw) degrees: __________
117 Use these values at run time? (1=yes, 0=no)
118 AFTER COMPLETING ALL ANSWERS, HIT <ESC> TO CONTINUE
119 (OR <Ctrl-C> TO CANCEL)
120 The INITIAL values for (XC,YC,ZC) are expressed in standard (e.g. UTM)
122 coordinates, and represent an approximation for the location of the
123 camera at the time of exposure.
124 • X: East aircraft position;
126 • Y: North aircraft position;
128 • Z: Flight altitude above sea level
130 The INITIAL values for (omega,phi,kappa) are expressed in degrees, and
132 represent an approximation for the cameras attitude at the time of ex‐
133 posure.
134 • Omega (pitch): Raising or lowering of the aircraft’s front
136 (turning around the wings’ axis);
137 • Phi (roll): Raising or lowering of the wings (turning around
139 the aircraft’s axis);
140 • Kappa (yaw): Rotation needed to align the aerial photo to true
142 north: needs to be denoted as +90 degree for clockwise turn and
143 -90 degree for a counterclockwise turn.
144 If ground control points are available, the INITIAL values are itera‐
146 tively corrected. This is particularl useful when the INITIAL values
147 are rather rough estimates.
148 The standard deviations for (XC,YC,ZC) are expressed in meters, and are
150 used as a priori values for the standard deviations used in computation
151 of the ortho rectification parameters. Higher values improve the re‐
152 finement of the initial camera exposure. As a rule of thumb, 5% of the
153 estimated target extents should be used.
154 The standard deviations for (omega,phi,kappa) are expressed in degrees,
156 and are used as a priori values for the standard deviations used in
157 computation of the ortho rectification parameters. As a rule of thumb,
158 2 degrees should be used.
159 If Use these values at run time? (1=yes, 0=no) is set to 0, the values
161 in this menu are not used.
162
164 i.ortho.photo, i.photo.2image, i.photo.2target, i.ortho.elev, i.or‐
165 tho.camera, i.ortho.transform, i.photo.rectify
166
168 Mike Baba, DBA Systems, Inc.
169
171 Available at: i.ortho.init source code (history)
172 Accessed: Mon Jun 20 16:47:34 2022
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177 © 2003-2022 GRASS Development Team, GRASS GIS 8.2.0 Reference Manual
179GRASS 8.2.0 i.ortho.init(1)