Small Business Innovation Research/Small Business Tech Transfer
Digital Array Gas Radiometer (DAGR), Phase I
Project Description
The innovation proposed here is a digital array gas radiometer (DAGR), a new design for a gas filter correlation radiometer (GFCR) to accurately measure and monitor CO2, CO, CH4, N2O and other key trace gases in the boundary layer from space, aircraft or ground-based platforms. GFCR is a well-known and proven technology for trace gas detection and monitoring. However, its effectiveness in downlooking applications has been limited, primarily because variations in surface albedo degrade the performance. Our DAGR approach builds on traditional GFCR concepts and combines several new key elements: two-dimensional detector arrays, pupil imaging (imaging the aperture), and a novel calibration approach. With these enhancements and appropriate signal processing, the DAGR design overcomes the historical limitations of GFCR in downlooking applications. In addition, this design significantly boosts the sensitivity and expands the dynamic range traditionally available to these sensors. Finally, the innovation provides a calibration technique that nearly eliminates errors due to detector drift effects. The result will be a compact, static, robust system that can accurately measure important boundary layer species from a variety of platforms.
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Anticipated Benefits
Pollutant and Agricultural Monitoring Aircraft and UAV measurements with a DAGR could be used to monitor effects of agricultural and industrial activities for specific emissions in geographical areas of interest. Agricultural operations produce a variety of particulates and gases that influence air quality, including NH3, H2S, CH4, N2O and airborne pathogens. These impact human health, the environment and climate. The Space Dynamics Lab (SDL), teamed with the Department of Agriculture, is developing systems to measure pollutant and greenhouse gases. DAGR would be an excellent compliment to these efforts. With innovative methods for combining gas cells and fiber optics, extremely small (the size of digital cameras) and sensitive DAGR instruments are possible. Climate Monitoring Greenhouse gas credit trading is becoming a sensitive issue, but a major obstacle is the inability to accurately measure baseline emissions. A DAGR system could provide such measurements. SDL is a participant in the Utah Science Technology and Research (USTAR) initiative, designed to bring new products to market. If successful through Phase II, GATS and SDL plan to work with USTAR to develop and market DAGR as a commercial climate-monitoring sensor. Two implementations are envisioned: 1) a ground based open-path system for local source monitoring, and 2) a light aircraft/UAV version for regional monitoring. Being insensitive to varying background albedo, DAGR sensors are well suited for sensing boundary layer gases such as CO, CH4, and N2O in downlooking solar scatter applications. The interest in these particular species stems mainly from their role in global climate change. Measurements of CO are essential to separate biomass burning fluxes from fossil fuel emissions. Tracers such as CH4 and N2O reveal the extent of horizontal mixing and spatial patterns of the age of the air. Future NASA missions called for by the NRC Decadal Survey are likely to include such measurements, and would benefit from the DAGR innovation proposed here. DAGR sensors could be configured for aircraft, low-Earth orbit or geostationary platforms. The DAGR design makes it impervious to misalignment and therefore vibration, resulting in a rugged instrument. Candidate NASA missions include ASCENDS, (Active Sensing of CO2 Emissions over Nights, Days and Seasons), GACM (Global Atmospheric Composition Mission), and Geo-CAPE (Geostationary Coastal Air Pollution Events). Additionally, a DAGR sensor could be used aboard planetary missions, for example to measure the spatial distribution of CH4 in the Martian atmosphere, thought to be an indicator of biological activity.
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Primary U.S. Work Locations and Key Partners
| Organizations Performing Work | Role | Type | Location |
|---|---|---|---|
Langley Research Center
(LaRC)
|
Lead Organization | NASA Center | Hampton, Virginia |
| GATS, Inc. | Supporting Organization | Industry | Newport News, Virginia |
Primary U.S. Work Locations
-
Virginia
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This is a historic project that was completed before the creation of TechPort on October 1, 2012. Available data has been included. This record may contain less data than currently active projects.