Electronic distance measuring instrument

摘要

PCT No. PCT/SE97/00396 Sec. 371 Date Nov. 18, 1998 Sec. 102(e) Date Nov. 18, 1998 PCT Filed Mar. 3, 1997 PCT Pub. No. WO97/33182 PCT Pub. Date Sep. 12, 1997The invention relates to a method and device for measuring distances through the atmosphere against a target through propagation time measuring. Measuring light signals are transmitted towards a target and light pulses reflected by the target are received. The distance measuring includes a coarse measuring procedure and a fine measuring procedure. During the coarse measuring procedure at least one time point is fixed after which the measuring signal from the target can be expected to appear. During the fine measuring procedure a number of measurements are performed. The signal information collection during the fine measuring procedure takes place in a matching time space after the time point fixed during the coarse measuring. Preferably, the measuring during the coarse measuring procedure takes place with one or a few measuring pulses and measuring during the fine measuring procedure with a number of measuring light pulses. The light pulses have then during the coarse measuring procedure a higher light intensity than the measuring light pulses during the fine measuring procedure.