Preliminary flight tests of pseudo-attitude using single antenna GPS sensing

This paper describes a novel method for aircraft control based on pseudo-attitude. The pseudo-attitude information consists of flight path angle and pseudo-roll angle about the aircraft velocity vector axis and is completely observable from single antenna GPS velocity measurements. Pseudo-attitude information is presented on a pseudo-attitude display which shows flight path angle and pseudo-roll angle instead of the traditional pitch and roll information, thus yielding direct indications of the actual flight path state. Flight tests in a Piper Arrow aircraft showed that pseudo-attitude is equivalent in performance to conventional attitude, with no subjective or objective differences between them. Possible applications of pseudo-attitude include its use as a backup attitude system, in guidance display or flight control schemes or for fault diagnostics in redundant systems