Measurement Devices Ltd (MDL), a provider of laser measurement technology and positioning and navigation systems, is providing the University of Aberdeen with a handheld laser rangefinder, the LaserAce 300, to measure bottlenose dolphins in the wild.

LaserAce 300, with its eyesafe class 1 laser, is designed to provide markets such as survey, forestry, utilities and quarrying with a lightweight, easy-to-use instrument for measuring distances, volumes, profiles, heights and missing distance measurements. The unit benefits these markets by reducing the survey time and helps surveyors to measure inaccessible or dangerous areas.

The scientists at the University of Aberdeen Lighthouse Field Station have been studying the Moray Firth population of bottlenose dolphins for more than 15 years. Photographs of natural markings on different dolphins have allowed the university to follow many individuals throughout this time however the barrier the institute faced was how to measure the dolphins successfully without capturing them or using very expensive or bulky photogrammetry equipment.

The sex and age of these animals is crucial for understanding the health and dynamics of animal populations. Information can be gained from photographs from a single camera, if the distances between the camera and the objective photographed are precisely and accurately known. This was deemed impossible until the arrival of MDL's LaserAce 300 hand-held laser rangefinder.

The LaserAce 300 would give reflectorless distances up to 300 m with an accuracy of typically 10 cm, which would be more than enough to capture and measure the distances to these dolphins.

Dr. David Lusseau at the University of Aberdeen commented, "Over the range in which we can take pictures of dolphins (10 - 70 m), we found that the rangefinder was able to estimate distances with an average standard deviation of 6cm, even better than what we were promised! Moreover the rangefinder was able to reliably measure distances to moving targets, which meant that we could try it on dolphins surfacing."

The scientists at the University of Aberdeen used the LaserAce 300, coupled to a digital video camera, to measure the dolphins. The information gathered gave the scientists an estimate of the total length of dolphins and they were also found that multiple estimates of the same individuals were in very close agreement.

The LaserAce 300's accuracy meant that the scientists at the University of Aberdeen were able to assess small length variations in wild dolphins and hopefully allow the scientists to determine the sex and approximate age of animals without having to capture them.

Source: MDL, Aug. 19, 2004

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