Abstract

An FM-CW radar is described which simultaneously furnishes three-dimensional velocity and absolute altitude information. The velocity is measured by means of a low-frequency FM-CW Doppler technique, and the altitude information by means of phase comparison on one of the sidebands of the received spectrum. The optimum radar parameters required for the two functions are completely compatible. Use of the first-order sideband permits operation of the system down to zero feet altitude; use of the second order to very nearly zero feet. Offset reference frequency techniques and narrow-band leakage elimination techniques permit system operation through zero speed and to negative speeds. Contrary to that of conventional FM-CW altimeters, the altitude measurement technique is unaffected by amplitude noise and by frequency (Doppler) noise due to vehicle motion. The radar technique is particularly applicable to helicopters, VTOL aircraft, lunar landing vehicles and possibly also to satellite rendezvous. Actual flight test results have demonstrated the feasibility of the radar technique.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.