Survey at Wroxeter using carrier phase, differential GPS surveying techniques

Abstract

In recent years the high-precision differential global positioning system (GPS) has become a significant technology with the areas of survey and civil engineering. The application of this technique to a large area archaeological site has been explored by undertaking surface survey, alongside geophysical survey, at the Roman town of Wroxeter. The GPS potentially removes any dependence on an existing map and allows positional fixes anywhere on the face of the globe. Carrier phase differential GPS allows real-time three-dimensional survey data to be collected in relative space to subcentimetre accuracy. Kinematic GPS survey facilitates the collection of data points at submetre intervals at the same speed as the operator walks or drives across a land surface. This technique is potentially of great significance to the recording of surface archaeological features in a three-dimensional form as a DEM (digital elevation model) or DTM (digital terrain model). Accurate three-dimensional digital data is expensive to collect in terms of man-hours spent using more traditional survey methods. Such data is a vital part of any GIS (geographical information system) based site or landscape analysis. Real-time kinematic (RTK) GPS can replicate the archaeological surface to a level of accuracy that creates a virtual three-dimensional cast of the topography. Copyright © 2000 John Wiley & Sons, Ltd.