GEOMETRIC TRANSFORMATION

A mathematical adjustment applied in the rectification of errors and restoration of images to geographical correctness or specific map projections. Each process of data collection, whether a manually digitised map, sensor or scanner, generates singular characteristics in the raw data. Errors and distortion which occur may be constant, systematic or random. These are generally checked and adjusted prior to the imagery being released for wider use and analysis. The corrected image is then supplied in a recognised co-ordinate system format. Further computation and adjustment may be required to match other images generated on different coordinate systems or lacking well-defined geometry.