Instrument Development:

RPV System for Trace Species Mapping

SSI Optical Gas Sensor Takes Off

In 1991, Spectral Sciences was asked by Thiokol Corp. (builder of the Space Shuttle booster rockets) to tackle a challenging problem in air pollution monitoring: evaluating the environmental impact from the launch of solid rockets. The hot exhaust gas rises so rapidly that measurements near the ground are useless, and it is extremely hazardous to fly a conventional aircraft close enough to the launch or test pad for good sampling. Fortunately, SSI not only builds fast, sensitive trace gas sensors, but also has as its President a nationally-recognized, award-winning designer of small RPVs (remote-piloted aircraft). In four months SSI fielded a custom-built RPV system for measuring HCl (hydrogen chloride) vapor in rocket exhaust clouds at 1 to 100 ppm levels with high temporal and spatial resolution. Flights of this system during a series of rocket ground tests in 1992 provided critical data for the evaluation of a new, low-pollution rocket fuel.

RPV System On-Site at Thiokol Corp., Elkton, MD, During October 1992

SSI's RPV System Measures Trace Gas Sources and Atmospheric Dispersal

SSI's innovative RPV system makes possible unique measurements of pollution from sources such as combustion exhausts and chemical leaks as well as climatological parameters such as temperature and humidity. It enables trace gases such as HCl, water vapor, carbon monoxide, and methane to be mapped over a wide geographic area tens to hundreds of meters above the ground with a spatial resolution of several meters and a temporal resolution as fast as 0.1 second. The heart of the instrument package is a sensitive, selective IR sensor based on our R&D 100 Award-winning IRMOLL lamp. A special flow channel built into the RPV provides instantaneous sampling of the unperturbed air stream. The RPV, which has a 4.6 m wing span, is agile (it can make a 180 degree turn in under 10 seconds) and rapid-climbing (6 m per second), so that many passes through the area to be sampled can be made in only a few minutes.

Creative Solutions for Atmospheric Measurements

SSI's RPV system provides but one example of how our fast, sensitive gas sensors can address difficult atmospheric monitoring requirements. If you have a critical measurement problem, we can help you find a creative solution.

For more information please contact Dr. Steven Richtsmeier