Recently our team received an email from a client about some short-range distortions in the scans using the Leica BLK360. They decribed the data as being mis-formed if the subject was reasonably close (within approximately 1500mm). The problem was less apparent for items further away.
After advising to ensure the lastest firmware is installed, it was determined that the mirror and glass surfaces of the unit could be dirty, and it was important to keep these surfaces clean.
In previous cases with laser scanners cleaning the mirror, even though it didn’t look like the mirror was overly dirty has made all the difference and fixed the problem.
The provided Leica Geosystems BLK360 User Manual describes the best course of action in Section 5.4 and 5.5
CR Kennedy Service Manager Greg Moran advises using a simple "dry" cleaning kit such as the one featured below with the following instructions.
The Photopro Kit https://crkphotoimaging.com.au/products/NPP-1 has two brushes ( small and large ) soft brush and the other end has another surface that can easily remove thumb prints etc. No chemicals or lens cloth is required. The proceedure tool approx. 20 seconds to clean up the faces that collect dust including the angled Nadir Plate below the rotating mirror.
The brush is the safest way to go and can be used on site when required.
Update 18 Jan 2019
In response to this post, we were sent the image below from our client Veris. Although this took a little more then a lens cleaning brush, the P-Series scrubbed up well and lived to scan another (next) day!