Abstract
The polarization behavior of the Leica Geosystems absolute distance meter is investigated in order to understand measurement noise and dropouts sometimes observed when the instrument is used with fold mirrors. A Stokes- Mueller calculus analysis suggests retardance in the fold elements is a likely culprit. We establish the heuristic that for folds in a single plane, successful operation is obtained when the sum of the ellipsometric angle u for each element in single pass is an integer multiple of 180°. The heuristic is validated experimentally, and found to have a tolerance in the range of ±12° to hold distance standard deviations to 10μm. Strategies to achieve this condition include keeping angles of incidence near 90°, tuning with angle of incidence, and judicious selection of mirror coatings.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have