Digital Photogrammetric Workstations25/01/2006 |
| A digital photogrammetric system is defined by ISPRS as: hardware and software designed to derive photogrammetric products from digital imagery using manual and automated techniques. Today the trend is to take the hardware component from off the consumer shelf, whilst specialised software has become the distinguishing competitive component. |
| Mathias Lemmens, editor, GIM International |
|
The hardware and software components of current Digital Photogrammetric Workstations (DPW) are often de-coupled. Many manufacturers answer no to the question whether hardware is included. It has often been advocated that one of the main advantages of Digital Photogrammetry (DP) over Analytical Photogrammetry (AP) is flexibility; AP requires specialised instruments for every product, whilst DP needs just one instrument, the computer. With DP the actual product is generated along software-supported workflows. However, this does not mean that all manufacturers offer general-purpose systems. On the contrary, the distinguishing element is that the various systems are dedicated to different applications and specific end-users. Some focus on a heavily map-producing environment, with high productivity and performance, where the work is done by highly trained end-users; others have close-range applications or the occasional GIS user in mind. Most DPWs are able to process, in addition to the traditional central projective images of aerial cameras, both satellite and close-range imagery. For many applications it is important that the system be able to adapt to the frequent release of various new, high-resolution airborne and space-borne sensors with their own data formats. Advanced mapping systems are able to handle many different sensor models and to carry out interior and relative orientation, aerotriangulation and DEM extraction in a (semi)-automatic way. In response to user demands for higher automation and more flexibility some manufacturers have even implemented automatic line-extraction modules for mapping features like road edges and shorelines.
|


