PHOTOMOD Solver – block adjustment module
PHOTOMOD Solver module is used in making block adjustments to strips and image blocks (common model construction and
exterior orientation). The module also has a powerful graphics interface for viewing adjustment results and detecting input
Main capabilities of PHOTOMOD Solver
Three methods of central projection imagery adjustment:
- Independent strips — used to check for gross errors—erroneous control point coordinate values, inaccurate tie point measurements, etc.;
- Independent stereopairs — used to increase accuracy achieved through the independent strip method. Detects more delicate errors,
possibly to a degree suitable for final adjustment;
- Bundle adjustment — used for final block adjustment.
As soon as the block is adjusted to meet accuracy requirements, further processing may begin (e.g. 3D feature extraction,
DTM creation and orthomosaicking).
One very useful feature of PHOTOMOD Solver is its ability to perform block adjustment in a “free model” mode. For example,
ground control points are not yet available, because field measurements have not been completed. “Free model” can be used to
eliminate “bad” tie points, ensure that tie point residual values are acceptable, and then start DTM creation and the 3D
vectorization processes. Later, when GCPs become available, the block is adjusted a final time, and all previously created
3D vector objects and DTMs are transformed from free model into “real” project coordinate
Note: It is not possible to build contour lines or create orthophoto in the “free model”.
Three adjustment methods for satellite scanner blocks:
- Generic — no sensor and survey related information available;
- RPC — satellite images are accompanied by Rational Polynomial Coefficients data;
- Rigorous — sensor parameters are known.