Patent ID: 7079228

Claim:
Combined laser-based apparatus for determining both altitude and ground velocity of an aircraft, said apparatus comprising: a laser source for emitting pulsed laser beams substantially at a predetermined wavelength over a first optical path; a plurality of first optical elements for directing said laser beams from said first optical path to a second optical path which exits said first optical elements; a plurality of second optical elements configured to form a telescope with a predetermined field of view, said second optical path and telescope field of view being fixedly co-aligned; an optical scanner disposed in said second optical path for directing said second optical path and telescope field of view to desired ground positions while maintaining the co-alignment thereof; said telescope for receiving from said desired ground positions Doppler wavelength shifted reflections of said pulsed laser beams within the field of view thereof and directing said received ground reflections substantially over a third optical path; an optical filter element disposed in said third optical path for separating the ground reflections of said third optical path into first and second portions that are dependent on the Doppler wavelength shift of said ground reflections; and processing means for determining altitude and ground velocity of said aircraft based on said first and second portions.