the same system is used for data acquisition, editing and
processing.
3.2 DEM measuring program within P-CAP
A special program has been developed for DEM measurement within P-CAP. It
offers a similar scope of functions as the PHOCUS measuring program MDTM and
includes for example:
- single point measurement
- grid measurement
- profile measurement with incremental recording
This PC version is characterized by a special feature. The area to be proc
essed, which may extend over several models, is specified in the project de
finition, with the boundary line being defined by a polygon of any size. The
same applies to the cut-out areas included (e.g. forests, builtup areas, wa
ter surfaces). The total area to be measured is covered by a bit map, in
which each element represents the status of a measuring point, e.g.:
- point to be measured
- point not to be measured
- measured point
- point rejected by the operator as not being measurable
The bit map ensures that each point is checked during the measuring process.
As a result, the grid points and profile points of the cut-out areas are
skipped by the program from the outset and the measuring speed is increased.
Moreover, the bit map enables checks across the model boundaries so that
omissions or double measurements can be recognized and avoided right during
the measuring process. Interrupted measurements can be resumed at any time.
The graphic output of the bit map on the colour display terminal provides an
overview of the current processing status of a DEM project.