Spitfire has been involved in LIDAR/Imaging monitoring surveys over the last few years in an industrial area along the Fraser River. On this occasion we were provided times in the early morning hours in January when water levels were at their lowest. Our LiDAR data would be integrated with multi-beam echo sounder data collected by hydrographic survey vessel providing a seamless topography above and below low water. Battling strong winds, below zero temperatures and hours before a snowstorm descended on the city, we successfully performed the night mission safely over trees and under a bridge using night vision and beacons lighting up the drone. The data was delivered in the same vertical and horizontal datums as the bathymetric data collected by the hydrographic survey vessel. Without imagery and a non-colorized point cloud it would normally be difficult to provide horizontal and vertical checks to aerial targets. However, our Accuracy Star Aerial Targets with 6 high reflectivity targets and known level arm offsets enabled us to automatically and accurately align the point cloud to ground control set by RTK GPS. In the Quality Control Report, we achieved an excellent three-dimensional RMSE of 0.013m well below our tolerance of 0.05m.

Traditionally this challenging survey along the sticky muddy shores of the river would be undertaken with total station or RTK GPS equipment by foot. Today we can capture topographic data in this area safely and in minutes. Drones prove to be an invaluable tool in efficiently acquiring larger areas of topographic data in the often-brief time frame of non-tidal and tidal low water levels.