Novel laser-based gas sensors for trace gas detection in a spacecraft habitat
Leleux, Darrin Paul
Tittel, Frank K.
Doctor of Philosophy
The principal objective of this research has been the development of advanced data reduction techniques and their application to real-time detection and precise concentration measurement of trace gases for use in spacecraft habitats. This is especially important for human life support technology in long duration space missions such as the International Space Station and future missions to Mars. Trace gas detection was performed using compact infrared diode laser-based absorption gas sensors. These sensors have proven to be very sensitive, selective and rugged to permit use in spacecraft environments. These same sensors can play an important role in unmanned exploratory programs of planetary surfaces or atmospheric research conducted by high altitude NASA aircraft. The infrared laser sources take advantage of recent significant developments of new infrared nonlinear materials, progress in diode and solid state lasers, and fiber optics technology. The techniques developed in this thesis include realtime Voigt fitting, simultaneous multi-species detection and Kalman filtering. These techniques were applied in several field campaigns including formaldehyde monitoring in downtown Houston, Deer Park and Channelview, Texas, as well as ammonia and carbon dioxide monitoring in a Biological Wastewater Processor at the Johnson Space Center in Houston, Texas.
Electronics; Electrical engineering; Environmental engineering