automatic aerotriangulation

[wangtao4321]

Without accurate exterior orientation elements, how to use the conventional bundle block adjustment to
determine the tie point location?

[Janne]

I cannot answer in general, I'll just describe a bit how its handled in EnsoMOSAIC.

Many times exterior orientation is not accurate, especially for small format and unmanned systems. This initial inaccuracy is taken into account by setting initial weights of exterior orientation relatively low compared to those of tie points or ground control. Realistic weights can then be determined by an iterative process, evaluating post-adjustment residuals for setting pre-adjustment weights.

Tie points locations are not determined in block adjustment but before it. During the adjustment points with high residuals are automatically eliminated from the result. This is carried out by dividing the block into sub-units for uniformly accurate process.

[wangtao4321]

I can use the feature extraction and matching algorithm to get tie point automatically.
The tie point location on the ground is calculated by using the exterior orientation similarly.
with the tie point location and the exterior orientation elements, then convention aerial
triangulation can be finished. that is what i want to do, does anybody have any idea?

[Janne]

The procedure you describe is principally the one applied in EnsoMOSAIC processing.