RECENT ADVANCES IN ANGLE ENCODER TECHNOLOGY

Surveying instruments like theodolites or laser scanners become smaller, more light-weight and easier-to-use while at the same time improving measurement performance. To allow this trend, the angle encoder, a crucial element of such an instrument, also needs to shrink. In this paper, we show how we were able to halve the diameter and the height of an angle encoder, while maintaining or even improving the angular performance. To this end, the alignment of the optical elements is changed, the mirror is integrated into the disc and the compensation algorithms were extended to account for harmonic errors of higher order.