Method and apparatus for determining a velocity
AssigneeDaimlerChrysler AG
InventorsSigmund Manhart, Elke Schmidt
Life of this patent
Estimating the term…
Abstract
A velocity such as wind velocity is measured based on a Doppler shift of a backscattered or returned laser signal. The Doppler shift of the backscattered beam is determined from a change in the polarization state or intensity shift of the received or backscattered signal after it has passed through a polarization-dispersive element (PD) and through a polarization analyzer (PA). The electrical signals (I1 and I2) generated from two partial beams provided by the polarization analyzer (PA) represent an the intensity shift. The signals are processed in a computer and the resulting information is displayed, for example.
Claims18
A method for measuring velocity based on the Doppler shift, said method comprising the following steps:
- (a) emitting a laser signal (SS) toward a target,
- (b) receiving a backscattered or reflected signal (ES) from said target,
- (c) passing said backscattered or reflected signal through a polarization dispersive element (PD) for producing a change in a polarization state of said backscattered or reflected signal,
- (d) passing said backscattered or reflected signal through a polarization analyzer (PA) for providing two partial beams representing an intensity shift that signifies said change in said polarization state,
- (e) converting (at D1 and D2) said two partial beams into respective intensity representing electrical signals (I1 and I2), and
- (f) processing said electrical signals (I1 and I2) in a computer for obtaining information regarding said velocity.
An apparatus for measuring velocity based on the Doppler shift, said apparatus comprising a laser (L) for emitting a laser signal (SS), a receiver channel for receiving a return signal (ES) backscattered from a moving target, an inlet (IL) for said return signal (ES), a polarization dispersive element (PD) positioned for receiving said return signal (ES) from said input and for receiving a reference signal representing a radiation signal reflected from a stationary target, a polarization responsive analyzer (PA) positioned to receive a signal from said polarization dispersive element (PD) for providing radiation intensity representing signals, means (D1 and D2) for converting said radiation intensity representing signals into respective electrical signals (I1 and I2), and a computer (R) connected to receive said electrical signals (I1 and I2) and said reference signal for processing and calculating said velocity based on said Doppler shift.
Dependencies are inferred from the claim text.