Spectra Geospatial Focus 35, Руководство пользователя

Страница: 90 / 109

6 Instrument Technology
Distance Measuring Technology
Spectra Geospatial FOCUS 35 Total Stations are equipped with a combined distance unit. This means
that the instrument can measure to a prism or to normal surfaces (reflectorless mode).
The laser distance unit is based on the phase comparison method. The distance unit is coaxial with the
line of sight and transmits an intensity modulated optical measuring beam that is reflected by a prism or
scattered by a natural surface on which the beam is directed. The phase difference between the
transmitted light and the reflected received light is detected and represents the distance.
In prism mode, the unit operates as a fast and precise long-range distance meter. In reflectorless mode,
the unit transmits a collimated visible red laser beam to the target point and then calculates the
distance between the transmitted and the received light.
The distance unit software will detect erroneous single distance measurements such as those caused by
an obstruction passing through the measurement beam, and will ignore such readings in the
computation of the final distance.
The unambiguous range for distance measurement is as follows:
l
Prism mode - 7,350 m (24,114 ft)
l
Reflectorless mode - 1,100 m (3,609 ft)
NOTE – Do not measure to a prism in reflectorless mode. Distances up to 1100 m (3,609 ft) are not
allowed because a Class 3 Laser is used for reflectorless distance measurement. For distances
longer than 1100m (3,609 ft), the instrument's distance accuracy is not guaranteed.
FOCUS 35 Total Station User Guide | 90