Abstract: A passive clear turbulence (CAT) detection system for use on-board an aircraft comprises: an antenna for receiving electromagnetic radiation and for generating electrical signals representative thereof; and a processor for processing the electrical signals with at least one CAT waveform signature to detect CAT activity in relation to the aircraft. Also disclosed is a method of detecting clear air turbulence (CAT) from an aircraft, the method comprising the steps of: receiving electromagnetic radiation and generating electrical signals representative thereof; and processing the electrical signals with at least one CAT waveform signature to detect CAT activity in relation to the aircraft.

Abstract: A passive clear air turbulence (CAT) detection system for use on-board an aircraft comprises: an antenna for receiving electromagnetic radiation and for generating electrical signals representative thereof; and a processor for processing the electrical signals with at least one CAT waveform signature to detect CAT activity in relation to the aircraft. Also disclosed is a method of detecting clear air turbulence (CAT) from an aircraft, the method comprising the steps of: receiving electromagnetic radiation and generating electrical signals representative thereof; and processing the electrical signals with at least one CAT waveform signature to detect CAT activity in relation to the aircraft.

Abstract: In accordance with the disclosed method, an attitude determining device which is installed onboard a mobile craft, like an aircraft, for example, at an unknown orientation with respect to the reference coordinate system of the craft senses its installation orientation with respect to an earth frame coordinate system when the craft is at rest to obtain a static orientation measurement thereof. Thereafter, an attitude of the mobile craft with respect to the earth frame is measured with the attitude determining device and such measurement is compensated with the static orientation measurement to obtain attitude information of the craft's reference coordinate system with respect to the earth frame coordinate system. The installation orientation of the attitude determining device may be sensed while the craft is at rest in either a leveled or unleveled condition.