An-Najah Staff

Several approaches exist for the creation of a digital cadastral overlay. These range from the simple digitization of the widely available tax maps, to the extensive field re-survey of all cadastral parcels. While the first approach is relatively inexpensive, and can be implemented in a short time period, it does not provide sufficient accuracy to satisfy all land information users due to the accuracy limitations of existing tax maps. On the other hand, even though the second approach achieves high accuracy, it requires high up-front finances and takes a long time to implement. There is consequently a need for another approach for building the cadastral overlay, which will be relatively inexpensive, implementable over a short period of time, and meet the accuracy requirements of the land information users. This approach should start with the coordinates digitized from tax maps and upgrade their accuracy incrementally through adjustment computation techniques using 'stochastic' geometric constraints as well as accurate survey data, which will become available over time. This paper describes such an incremental approach and reports on some of the initial results.