GEO-LOCATING HISTORICAL SURVEY DATA AND IMAGES – A CASE STUDY FOR THE CANNING RIVER, PERTH, WESTERN AUSTRALIA
The aim of this project is to create the required framework to allow the transformation of the Canning River location survey data captured by Dr. J. A. Ludwig Preiss from 1841 into today’s maps and to utilise visualisation techniques to analyse the results. The original survey data includes distances and bearing observations as well as 14 historical maps. Firstly, the old survey data (includes distances and angles measurements) is plotted into a local coordinates system using modern surveying software (MAGNET Office). Then, common points (unchanged locations) are identified by comparison with the plotted and the current paths of the river. A similarity and affine transformation are used to find transformation parameters that allow to geo-locate the plotted river into the current geodetic datum (MGA94). The calculated Root Mean Squared Errors (RMSE) are 21.7 m and 21.1 m obtained by geo-locating the common points using similarity and affine transformation, respectively. For geo-referencing the historical maps, the similarity, projective and Thin Plate Spline (TPS) transformations have been applied. It has been found that one point of interest (referred to as Nairn’s house), which was drawn in one of the historical maps, still exists today (now known as Maddington Homestead). The distances from the actual position of Nairn’s house to its position in the georeferenced maps using similarity, projective and TPS are 11.8 m, 13 m, and 14 m respectively. All the gained information and map details are utilised in creating a dynamic visualisation suitable for comparing the generated map and historical map with modern aerial imaging and DTM data.