Description: In this Small Business Innovative Research (SBIR) effort, Los Gatos Research (LGR) proposes to employ incoherent Cavity Ringdown Spectroscopy (iCRDS) to develop a compact, cost-effective nitrogen dioxide (NO2) analyzer for deployment aboard miniature unmanned aerial vehicles (UAVs). This portable instrument will provide rapid (1 Hz), highly accurate (to better than ± 1 ppbv) quantification of NO2 with minimal external calibration or consumables gases. Moreover, due to the inherent benefits of iCRDS, the analyzer will be selective, robust, and economical. The resulting instrument will allow researchers in NASA's Earth Science Division to use miniature UAV deployments to complement satellite observations on the Geostationary Coastal and Air Pollution Events (GEO-CAPE) mission. The in-situ data will provide higher spatial resolution and vertical profiling near the highly inhomogeneous NO2 sources, as well as providing correction factors for GEO-CAPE coastal measurements.

Benefits: Besides its application to NASA, a compact, ultrasensitive NO2 analyzer also has significant commercial applications for environmental compliance monitoring, industrial process control, and scientific instrumentation. The proposed work is essential in making these instruments more compact, rugged, and cost competitive, and will thus enlarge the potential market size significantly.

The Earth Science Decadal Survey recommends NO2 monitoring as part of a mission dedicated to the measurement of tropospheric trace gases and coastal ocean color. In response, NASA is developing the Geostationary Coastal and Air Pollution Events (GEO-CAPE) mission. This mission measures both air pollution and ocean color, and targets a variety of species, including NO2. Many NO2 sources exhibit large spatial inhomogeneity and increased spatial and vertical resolution is required to interpret and verify satellite data. Likewise, ocean color measurements must be corrected for NO2 concentrations. In both cases, in-situ, airborne measurements of NO2 are required to complement the GEO-CAPE data. In the past, NASA has made such in-situ measurements using comprehensive, large-scale, field campaigns on piloted aircraft. Future campaigns will rely on smaller, manned and unmanned aircraft such as the SIERRA UAV and Aerosonde. Thus, new instrumentation is required that can autonomously measure NO2 while meeting the size, weight, and power limitations of these smaller aircraft.