Laser scanning targets where there are high amounts of traffic (vehicle or pedestrian) can be problematic if maximum coverage is required. The Topcon GLS-1000 scanner has the facility to undertake “detailed” scan. In this mode, it repeats the data acquisition within the specified scan area two or three times. The final dataset will contain only the most distant returns and noise will be effectively removed.
The example here was on a busy dual carriageway at rush hour. A comparison of the two datasets is shown below. Scan time is increased, however the most important thing – maximum data coverage is easily achieved.
Side view comparison
There are still some elements of noise which may be attributable to objects (i.e. vehicles) that were in the same location for each of the multiple passes.