Determining position and movement of object, esp. for vehicle position sensor

摘要

A transmitter/receiver unit has two transmitter/receiver modules (1,2) aligned in different directions. At least partially overlapping different regions of the object are illuminated by the two modules at different aspect angles. Signals of different frequencies are emitted by the two modules and reflected signals received with Doppler frequency shifts. At least one of the modules receives the scattered Doppler shifted signal from the other module. The Doppler frequencies and at least one Doppler frequency difference are determined and evaluated.