High Accuracy Photogrammetry of Historic Rock Art

Abstract

The petroglyphs of Petroglyph Park, Peterborough, created by the Algonquin Peoples between 900 and 1400 A.D., were documented in 1983 by the Heritage Recording Directorate of theGovernment of Canada. With the aim of rerecording the glyphs again at a later date to monitor the conditions and weathering, several sets of photogrammetric stereo pairs were taken of the site using Zeiss UMK and a Wild P-31 film cameras. After this project was completed, the site became designated as sacred and photography was no longer permitted, thus rendering the completion of a second recording of the site all but impossible. Therefore, the photographs taken of these magnificent petroglyphs in the 1980s are the most recent documentation available. Using the ADAMTech Mine Mapping Suite, developed in Perth Australia for the mining industry, I was able to bring these archival photos to life by creating dense 3D models that rival those produced by LiDAR. I used the photos, digitized in Ottawa on a Wehri RM-6 photogrammetric scanner, to create 3D models of the glyphs. A similar Federal project from Writing on Stone National Park in Alberta also used film photogrammetry to record the glyphs at that site in 1982. From these images as well I was able to compile 3D models. It is hoped that by scanning the original glass-plate negatives from the 1980s, and not the film copies, as we have done thus far for both projects, measurement data of even greater accuracy (down to 60um) and density can be achieved.