Medium-scale Mapping Research Articles

Large and medium scale mapping of Sydney

Large and medium scale mapping of Sydney

Vertical Control for Independent Models Blocks

In simultaneous block adjustments vertical control points need to be located in dense cross chains if no auxiliary information is available. One additional perimeter control point each between them strengthens the solution, and a further reduction of the vertical block deformation is achieved by normalizing the x-residuals in the projection centers. The use of auxiliary data leads to substantial saving of vertical control points. The interaction between vertical control point distribution statoscope-, APR-, lake data, and combinations of these is studied with several well-controlled independent model production blocks adjusted with PAT-M-43. The tests indicate that the bridging distance can be increased to the extent that there is virtually no need for control points within the block for small and medium-scale mapping purposes. /ASCE/

Combined Block Adjustment of APR Data and Independent Photogrammetric Models*

Based on the computer program PAT-M for block adjustment by independent models, an extended system is presented for the combined simultaneous block adjustment of photogrammetric models with APR and/or statoscope data, including photogrammetric height measurements of shorelines of lakes, if available. The system is intended for small- and medium-scale topographic mapping. Because of possible application to very large blocks, is is expected to be of great economic importance. The paper develops the basic mathematical formulas for the combined adjustment. In view of efficient and economic computation, some modifications are proposed, which the present programing of the system takes into account.