Patent ID: 6031600
Filing Date: 2000-02-29
Classification: G01S

Abstract:
A method for determining a position of an object using a measurement device, the measurement device including an optical transmitter and an angularly resolving optical receiver situated at a predetermined distance from the optical transmitter, the method comprising the steps of:defining each of a plurality of resolution cells as a function of a respective set of discrete predetermined transmission and reception angles, the discrete predetermined transmission and reception angles providing an angular resolution of the optical transmitter and the angularly resolving optical receiver;for each respective set of the discrete predetermined transmission and reception angles, allocating an address in a memory device for storing a corresponding predetermined phase difference and a corresponding predetermined distance from the measurement device to a corresponding cell of the resolution cells;emitting a light beam, using the optical transmitter, at a particular varying transmission angle;modulating the light beam to generate a first modulated signal;receiving a radiation reflected from the object, using the angularly resolving optical receiver, at a particular reception angle;modulating the received radiation to generate a second modulated signal;determining a phase difference between the first modulated signal and the second modulated signal;identifying a particular cell of the resolution cells as a function of the particular varying transmission angle and the particular reception angle, wherein the object is located in the particular cell; anddetermining the position of the object within the particular cell as a function of:the determined phase difference,the predetermined phase differences, stored in the memory device, which correspond to the particular cell, andthe predetermined distances, stored in the memory device, which correspond to the particular cell.