Optical electronic distance measuring apparatus with movable mirror
US5455670A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 27, 1993 |
| Grant date | Oct 3, 1995 |
| Priority date | — |
| Expiry date | May 27, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S2013/466
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A rangefinder system employs three laser rangefinders for determining three dimensional coordinates, each rangefinder using a steerable mirror for aiming the rangefinder beams at a series of retroreflectors. The beams are modulated at 1.5 GHz. The system includes a signal at an offset frequency of 1 kHz for phase detection. A digital phase detector under control of a local computer, as is the mirror, computes phase difference which is used to measure the distances to the retroreflectors. Correction is made for zero point phase drift of the circuit of each rangefinder and a benchmark reference to a distant retroreflector corrects for atmospheric effects on the measurements. A central computer directs the implementation of the tasks of the local computers of each rangefinder and computes and displays trilateration computation results made from the three rangefinders. The system can measure the distance to five different points per second with ranges up to 120 m at all accuracy of about 50 .mu.m.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.