Laser altimeter sensor assists conservation groups to improve the scaling accuracy of photographs.
Unmanned aerial vehicles (UAVs) have become an important tool for conservation practitioners and have been successfully applied in game counting in Kenya, seal monitoring in the Arctic and for anti-poaching work in Southern Africa. One area of particular interest is in accurate sizing of animals without direct human contact. Sensor-controlled UAVs can be implemented without interfering with the animals, reducing disturbance to the environment and improving the safety of conservationists.
LightWare Optoelectronics, a South African based laser manufacturer, has been assisting conservation groups with laser altimeters to improve the scaling accuracy of photographs taken from both drones and full size aircraft. They recently did some work with the Center for Research into Ecological and Environmental Modelling (CREEM) based at the University of St Andrews in Scotland. CREEM is involved in a variety of marine animal research projects requiring accurate orthophotos for geospatial measurement to determine population density, movement and behaviour, as well as the size and health of the animals.
Recently conducted research involved photographing harbour- and grey seals in their natural environment from a UAV. The University’s requirements were particularly demanding as they needed to fly over sandy beaches, wetlands and the sea in order to capture their images. Using a laser altimeter under these conditions is very challenging as water tends to absorb the laser light and scatter the remaining signals away. Initial test flights over a beach were conducted with a standard LightWare SF02/F laser altimeter, which has an operating range of up to 50 meters.
The SF02/F gave good consistent measurement up to a height of 30 meters, but continuously lost signal above this altitude. “This is quite an impressive performance for our entry level product under such challenging conditions.” says James Portman, Managing Director of LightWare. “Our aim is to be the leader in laser rangefinding technolgies and as such we have used the data received from St Andrews to dramatically improve our ability to handle intermittent signals, as well as to improve the sensitivity of the laser detector.”
A new product was thus developed with improved capabilities over water and greater altitude measurements over solid ground, with a distance measuring capability in excess of 120 meters. LightWare aims to launch a beta version of this new product, called an SF11/C, before year-end 2015 to further assist the conservation community’s vital work.