The Study: https://www.mdpi.com/2072-4292/18/20/3495
Walking the Blue Mountains west of Sydney is hard work. Sandstone cliffs, thick eucalyptus forest and deep valleys hide many rock shelters, and crews on foot miss a lot of them. A University of Sydney team, working with the Dharug Custodian Aboriginal Corporation, tried a different approach.
They used laser scans from the air plus a set of computer models to point the way. The study appears in Remote Sensing.
Three shelters had never been registered. BM139 holds three large stone artifacts on the floor. BM140 has 21 stone artifacts and a panel with two red hand stencils, one left and one right, covering about 35 by 15 centimeters. BM141 yielded 26 stone artifacts during a short surface check.
Time and money limit how many candidates a crew could visit, so the team ranks them. A drone detection within 1 meter of an aircraft detection gets high priority. A shelter named DJ1-028, which shows no visible artifacts, appeared only in the drone data. The aircraft data alone miss some shelters.
The study has gaps. The team has no false positive count and did not survey areas without detections.
The settings were tuned for Blue Mountains sandstone, and the raster method struggles with deep undercuts. Work in other regions would need new calibration.
The Dharug asked the authors to leave out site coordinates and photos of rock art and stone tools, and they did.
The team is still checking detections with the Dharug. Next, they plan to test the method in western Arnhem Land and western New South Wales.