Responses to users: The continuing evolution of commercial digital photogrammetry

Although well established, digital photogrammetry continues to change. More sources offer imagery which can be treated photogrammetrically. Users need improved scanner performance as they attempt to offset costs by feeding cl usters of workstations or establishing bureau services; increased speed, va riable pixel size, use of roll film and "on the fly" dodging are desirable scanner characteristics. On the workstation side, the demand for the Window s NT platform has been irresistible. New applications and the quest for hig her productivity have resulted in demands including output of orientation d ata to analytical plotters, processing of data from airborne GPS and inerti al measurement unit (IMU), triangulated irregular network (TIN) DTMs, autom ated radiometric balancing in mosaicking, smoother operation within feature collection and batch processes. Moreover, the market place itself changes, with suppliers, their customers and the end users all competing for positi on.