Abstract

One of the challenges of an all-optical air data system is to measure the local atmospheric parameters of interest (e.g., pressure altitude, true air temperature, humidity, etc.), all with a sensor that meets size, weight, and power requirements. A variety of sensor techniques have been investigated at HDOS for the altitude range 0–100 km and are reviewed here. The ideal technique would allow one to reach out to the nearby undisturbed air and would measure a physical or spectroscopic parameter related to the desired atmospheric parameter without requiring knowledge of the absolute power in transmitted or received power in the optical probe beam. This ideal technique is not usually possible because of a variety of fundamental and practical limitations. The more practical techniques reviewed here include cooperative spectral absorption near 200 nm, cooperative laser absorption near 760 nm, cooperative laser absorption near 860 nm, and laser-induced fluorescence near 200 nm.

© 1991 Optical Society of America