How fast is the Topcon GLS-2000 Scanner?
Not an official, or recommended test by any means, but the video below gives an idea of the time it takes to do a full 360 degree scan with this instrument in high speed, 12.5mm @10m resolution (including capturing images). The video was captured using a GoPro HD Hero 3+ taped onto the front handle of the scanner. Rather than sit through the entire real time scan we’ve sped it up by 8x.
Having been in the 3D imaging business for a number of years, we have come to realise that there is a world of difference between the published speed of an instrument and the cumulative time it takes to get an acceptable, high quality deliverable to a client.
Good field practice requires planning, QA checks and supplementary activities such as external photography, avoiding shadows from passing traffic, note taking to name but a few. In fact when using very fast scanners, errors creep in purely due to the pressure of ’must move on, scanner’s finished.’
As mentioned in our post about initial field trials with the GLS-2000, the scanner is impressively fast. The table below provides some data on timings at different resolutions and speed settings. Please note that these figures, whilst coming from the Topcon engineering team are not from a full production unit but are expected to be the same. Our tests were very close to the published values in any case.
In addition to the scan times, in all cases the image acquisition takes around one minute. It is interesting to note that if the class 1 eye-safe laser was used, the scan times are slower (48k pts). We did a test on High Speed mode versus Standard which will be presented in a separate case study. Both modes produced excellent data, however the standard mode provided better resolution of dark surfaces such as roof slates and lead flashing.