1i.ortho.init(1) GRASS GIS User's Manual i.ortho.init(1)
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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.
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11 imagery, orthorectify
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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]
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21 Flags:
22 -r
23 Use initial values at run time
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25 -p
26 Print initial values
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28 --help
29 Print usage summary
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31 --verbose
32 Verbose module output
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34 --quiet
35 Quiet module output
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37 --ui
38 Force launching GUI dialog
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40 Parameters:
41 group=name [required]
42 Name of imagery group for ortho-rectification
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44 xc=float
45 Initial Camera Exposure X-coordinate
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47 yc=float
48 Initial Camera Exposure Y-coordinate
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50 zc=float
51 Initial Camera Exposure Z-coordinate
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53 xc_sd=float
54 Apriori X-coordinate standard deviation
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56 yc_sd=float
57 Apriori Y-coordinate standard deviation
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59 zc_sd=float
60 Apriori Z-coordinate standard deviation
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62 omega=float
63 Initial Camera Omega (pitch) degrees
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65 phi=float
66 Initial Camera Phi (roll) degrees
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68 kappa=float
69 Initial Camera Kappa (yaw) degrees
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71 omega_sd=float
72 Apriori Omega (pitch) standard deviation
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74 phi_sd=float
75 Apriori Phi (roll) standard deviation
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77 kappa_sd=float
78 Apriori Kappa (yaw) standard deviation
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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.
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89 The use of i.ortho.init (menu 6) is only required when rectifying a
90 tilted or oblique aerial photo.
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92 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.
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103 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)
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121 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.
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125 • X: East aircraft position;
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127 • Y: North aircraft position;
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129 • Z: Flight altitude above sea level
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131 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.
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135 • Omega (pitch): Raising or lowering of the aircraft’s front
136 (turning around the wings’ axis);
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138 • Phi (roll): Raising or lowering of the wings (turning around
139 the aircraft’s axis);
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141 • 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.
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145 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.
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149 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.
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155 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.
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160 If Use these values at run time? (1=yes, 0=no) is set to 0, the values
161 in this menu are not used.
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164 i.ortho.photo, i.photo.2image, i.photo.2target, i.ortho.elev, i.or‐
165 tho.camera, i.ortho.transform, i.photo.rectify
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168 Mike Baba, DBA Systems, Inc.
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171 Available at: i.ortho.init source code (history)
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173 Accessed: Saturday Jan 21 21:16:46 2023
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175 Main index | Imagery index | Topics index | Keywords index | Graphical
176 index | Full index
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178 © 2003-2023 GRASS Development Team, GRASS GIS 8.2.1 Reference Manual
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182GRASS 8.2.1 i.ortho.init(1)