Carrying out topographical surveys of facilities such as hospitals, schools, water- and sewage-treatment plants and golf courses with a drone is every bit as accurate as real-time kinematic global-positioning system (RTK GPS), which is the standard GPS equipment surveyors use to acquire data point by point. We proved the spatial accuracy of drone surveys to be within 2-3cm when compared to RTK GPS in a white paper we published in early 2013. However, drones deliver much richer and more quality assured data set to the client, all at a significantly lower price, in a much shorter timescale. You can now survey an area of land with a drone in less than one hour, which would normally take up to six weeks with traditional equipment. Baseline Surveys was awarded a contract by the Department of Education recently, to survey five schools in Blarney (Co Cork), Lismore (Co Waterford), Cahir (Co Tipperary), and Newtown and Waterpark in Waterford city. The contract required accurate and detailed topographic surveys to be carried out on each site. Our price was significantly lower than our competitors due to using our remotely-operated survey system – the ROSS-Copter drone – to carry out the topographical surveying. One of the schools was located on over 30 acres with very detailed topography, which we surveyed in under ten minutes from the air. This would have taken four days using ground-based survey equipment.

Managing GPR and CCTV subcontractors

---

As a ground-penetrating radar (GPR) and closed-circuit television (CCTV) survey of the underground utilities was also required by our client, co-ordinating and managing the GPR and CCTV subcontractors was a much easier task because we surveyed all five sites using a drone. For each sub-contractor, we had to prepare specific maps showing services so that they could carry out their work. Traditionally, we would have had to wait to until we had completed each survey before the GPR or CCTV could commence. This also saved the client time on completing the overall survey project. Another time- and cost-saving factor was that we did not need to return to site to provide extra survey information requested from us, which was beyond the original specification, but was required by the design team. With our drone, we scan every square inch of a given site, so we have a lot of extra information at our fingertips, such as cable-stay positions, pipe outlets, electrical poles, heights, fence lines and heights of hedges. As traditional survey methods just pick up the detail initially required, the traditional surveyor has to return to site to survey in the extra detail required. This is normally costly and time consuming, which the drone method of surveying completely avoids. The deliverables were far more intuitive to read, as both the topographic and GPR surveys could be directly overlaid onto the aerial imagery in computer-aided design. If you are interested in having a site surveyed by drone, further information on Baseline Surveys is available here. You can phone Paudie Barry on 086 2535285, or email him at paudie@baselinesurveys.ie. Paudie Barry is a land surveyor/unmanned aerial vehicle operator and managing director with Baseline Surveys Ltd.