Patent ID: 6268829
Filing Date: 2001-07-31
Classification: G01S

Abstract:
A Doppler direction finder comprising:at least one antenna spaced from a rotation point, said at least one antenna arranged in use, to be rotated physically or electronically about said rotation point, said at least one antenna being arranged to provide a first output signal comprising a signal received by said at least one antenna combined with a Doppler shift component;circuitry for providing a second output signal comprising said received signal without said Doppler shift component;circuitry for processing said first and said second signals to obtain said Doppler shift component, said received signal comprising a modulated carrier wave and said processing circuitry being arranged to combine said first and second signals to cancel the modulation component of the received signal; andcircuitry for determining from said Doppler shift component the direction from which said received signal is received.