Patent · US Expired

Laser doppler and time of flight range measurement

US4818100A · kind A · utility

30Cited by
7References
10Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 30, 1987
Grant dateApr 4, 1989
Priority date—
Expiry dateSep 30, 2007

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01S17/87
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A hybrid laser distance gauge utilizes complementary simultaneous measurements based upon both Doppler and time of flight principles. A complete record can be produced of the location and shape of a target object even when the object has severe discontinuities such as the edges of a turbine blade. Measurements by the two principles are made by using many optical elements in common. The Doppler measurements have an open loop optical/electronic arrangement in which the Doppler shift is converted to a voltage by a phase locked loop. The time of flight measurements are made at one or more harmonic frequencies of a mode locked pulse envelope wave train, for unusually accurate and unambiguous distance data.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.