There is an important need for accurate measurements of tropospheric wind altitude profiles. These wind systems have
long been recognized as one of the primary unknowns limiting weather forecasting over timescales of several days.
Typical measurement architectures have focused primarily on space-based approaches, using a high-powered and highly
effective Light Detection and Ranging (lidar) system.
This paper discusses architectures for low-altitude space missions. The architectures are analyzed in the context of a
weather forecasting system for the Gulf of Mexico region during hurricane season. The architecture studies were
developed by collaboration between a class of engineers who are part of the University of Michigan's new Space
Engineering program and Michigan Aerospace Corporation, a University of Michigan spin-off company specializing, in
part, in lidar systems.
The Molecular Optical Air Data System (MOADS) is a compact instrument designed to measure aircraft airspeed as well as the density of the air surrounding the aircraft. Other air data products provided by the instrument include density altitude, angle of attack (AOA), angle of side-slip (AOS), and Mach number. MOADS is a direct-detection LIDAR that measures these air data products from fringe images derived from a Fabry-Perot etalon. Determination of airspeed and direction is achieved through three telescopes that view a fixed air volume ahead of the aircraft turbulent flow field. This method reduces the measurement error as compared to traditional measurements made from within this turbulent region. As a direct detection LIDAR instrument, MOADS is capable of collecting both molecular and aerosol LIDAR returns, which allows operation in clear air as well as in aerosol-filled atmospheric regions. A second prototype was designed, built and tested. This MOADS prototype has been validated in a laboratory wind tunnel. Presented here are the airflow velocity measurement results from ground testing and vibration test measurements.
The Molecular Optical Air Data System (MOADS) is a compact optical instrument that can directly measure aircraft velocity, as well as the density of the air surrounding the aircraft. From these measurements, many air data products can be determined. Successful MOADS operation has been demonstrated in the laboratory using a wind tunnel. Recently, a MOADS prototype was designed and built in order to complete an upcoming flight experiment aboard a Beechcraft King Air 300. This flight program will be a significant milestone for direct detection lidar systems configured as an air data system aboard an aircraft. The background of the technology, ground experimentation summary of results, flight experiment approach, flight prototype design, and flight experiment planning are discussed.