Aerial Triangulation 2D Block Adjustment
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Aerial Triangulation 2D block adjustment in Noobeed offers 3 options of mathematic model, namely conformal (4 parameters), affine (6 parameters), and 2nd polynomial (12 parameters). All include in the same class, "AT_2D". The following are some of its beauty that might be hardly to find in other programs.
Data and Output
The photo coordinates measurement data are in the file "obs_xpyp.txt", the same data set as in bundle block adjustment. See the example of Bundle Block Adjustment.
The ground control coordinates data are in this file, "obs_gcp_xy.txt".
These are really all you need. Now it's time to do data processing.
It is always possible to type interactively on the screen. However, writing a program is also a good choice, like this.
set path "c:\WHEREVER_YOUR_DATA_ARE"
Blk = AT_2D()
/ this is default values of SD (image rectangular coordinates)
Blk.sd_xpyp() = 0.030
Please notice the option of adjustment in the last statement, it is a 2nd order polynomial transformation. Other options available are "conformal" and "affine".
Type the above program, using a text editor, then save it in a file, e.g. "AT.prg". Then load it, and run it.
Here is the result, "at_2d_out.txt". Please be advised that the adjustment results might not be as good as those come from a bundle block block adjustment, which is the real correct model of this data set. The value of the standard deviation of unit weight, a unit-less parameters, tells how good the model fits the data. This is a good example to appreciate the extreme accuracy of the bundle block adjustment mathematic model.
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