Target Scanning with the GLS-2000
As mentioned in the previous post, the Topcon GLS-2000 is a survey grade instrument that can be attached to a standard tribrach to allow occupation and backsight measurements over a known point. Previous Topcon GLS scanners used a bespoke highly reflective target that could be attached (magnetically or adhesively) to a special T mount or any flat surface. Whilst testing a production Topcon GLS-2000 laser scanner, we spotted an option under target scanning to make a backsight using a prism.
The target scanning process was very simple – tap on the live video image on the scanner’s screen to point roughly in the direction of the prism. The scanner then carries out a coarse scan and then a fine scan of the prism target. If the target scan is successful, a circular target is shown on the screen and a red laser dot appears from the centre of the prism. We tried out a Leica 360 degree prism, a Laserscanning Europe mini prism and a Topcon standard prism and all worked well. Obviously the scanner has to be told the prism offsets to give the correct coordinate.
We’re particularly excited about this feature of the GLS-2000 because it means that there is much greater scope for projects like monitoring where standard prisms can be used. Overall it is a cost effective and fast way of achieving great results with kit that every surveyor has in the boot of his or her car.