Defined as the procedure of establishing the geometric relationships among overlapping and side lapping photographs for determining the positions of supplemental horizontal control points
Reduces substantially the control required by field methods
Photogrammetry â€¦. Lecture 11 Dr. Steve Ramroop 07/11/10 GEM 3366
3.
Triangulation Photogrammetry â€¦. Lecture 11 Dr. Steve Ramroop 07/11/10 GEM 3366
Triangulation calculates:
The position and rotation of the camera each time an image was exposed (Exterior Orientation Parameters)
The X, Y and Z coordinates of tie points
4.
Overlap between Runs or Swaths Photogrammetry â€¦. Lecture 11 Dr. Steve Ramroop 07/11/10 GEM 3366 30% overlap between runs or swaths Run #1 Run #2
Aeotriangulation adopts photogrammteric triangulation which establishes the geometric relationships among overlapping and sidelapping photographs to determine supplemental horizontal and vertical control points
Aeotriangulation is performed using one of two methods:
Semianalytical (or independent model triangulation)
Analytical (or bundle block)
Photogrammetry â€¦. Lecture 11 Dr. Steve Ramroop 07/11/10 GEM 3366
Modelâ€™s relative orientation is done instrumentally on the plotter or analytically using a computer program, but the scale transfer between successive models is accomplished analytically
Hence each model are independently generated
Each model will have at least 3 tie points in common
Photogrammetry â€¦. Lecture 11 Dr. Steve Ramroop 07/11/10 GEM 3366
Coordinates for the second overlap is transformed mathematically by making coordinates of the left-hand perspective center of the first overlap and then rotating the second coordinate system about its three axes to make the points coincide with the first overlap
Photogrammetry â€¦. Lecture 11 Dr. Steve Ramroop 07/11/10 GEM 3366
11.
Photogrammetry â€¦. Lecture 11 Dr. Steve Ramroop 07/11/10 GEM 3366
Image point-measuring instruments (comparator, analytical plotter, workstation) are used to measure the x-y plate coordinates of each tie point and control point in each photograph
Sequence of mathematical models are formed from which strip coordinates are derived
Mathematical model represent the geometric relations between object space, perspective centers, and photographic images
Photogrammetry â€¦. Lecture 11 Dr. Steve Ramroop 07/11/10 GEM 3366
After each iteration residuals calculated for each measurement
Photogrammetry â€¦. Lecture 11 Dr. Steve Ramroop 07/11/10 GEM 3366 0.912 0.282 0.513 0.589 0.766 0.054 0.386 0.054 0.674 0.195 0.054 0.049 If every difference between these values is less than the Convergence value, the iterations will STOP Indicates that the triangulation has met the required accuracy Iteration #1 #2 0.432 0.153 0.321 0.654 0.543 0.044 0.436 0.021 0.434 0.087 0.111 0.024
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