Precision Remote Sensor for Oxygen and Carbon Dioxide

Mesa Photonics proposes development of a passive optical sensor for simultaneous high-precision measurement of oxygen and carbon dioxide profiles within the full atmospheric column. The approach, which is based on near-infrared heterodyne spectroscopy using solar occultation (i.e., direct solar viewing), is called Precision Heterodyne Oxygen-Calibrated Spectrometer, or PHOCS. Oxygen measurements will provide dry gas corrections and – more importantly – will determine accurate temperature profiles that, in turn, improve the precision of the carbon dioxide column retrievals to better than 1%. Planned instruments will complement results anticipated from the Orbiting Carbon Observatory (OCO-2), Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS), and ground-based Fourier transform spectrometers. PHOCS instruments will be small (not much bigger than a pair of binoculars), light weight, and low power. In keeping with one of the goals of this SBIR topic, planned instruments will be initially configured for operation on the ground, and have size, weight, and power (SWAP) characteristics suitable for easy ground mobility and well as airborne or space-borne deployment. The Phase I project will test an all-fiber-optic heterodyne receiver that will simplify optical design and ensure long-term optical alignment. Oxygen measurements will use the near-infrared band the 1.27 micron wavelength region instead of the more commonly used band at 0.76 microns. The longer wavelength band is weaker; precise lineshapes of many individual rotational lines will be measureable without complications due to highly saturated absorbances or instrument line shape functions (ILS). Carbon dioxide measurements will use the well-characterized band at 1.57 microns.

Motivation for the NASA commerical applications is described well by Rebecca A. Washenfelder in her Ph.D. thesis (Caltech, 2006), " To predict future climate change, we must accurately predict future atmospheric concentrations of CO2 and CH4. The current budget has typically been inferred from top down analyses of measurements from a global network of surface sites. These measurements are highly accurate, but have limited spatial coverage. In addition, accurate knowledge of local planetary boundary layer dynamics is necessary to determine fluxes. Column measurements, defined as the vertical integral of gas concentration, can complement the existing in situ network. Because column measurements sample a larger portion of the atmosphere, they exhibit less variability than surface data, while retaining information about surface fluxes. Column measurements are not influenced by planetary boundary layer dynamics, and do not suffer from the resulting correlation between exchange and transport." PHOCS is intended to help meet this research need. Our approach is particularly useful because of its flexibility in deployment methods. Commercial instruments can be mounted on the ground, on board ships, or on aircraft and research balloons. Size, weight, and power (SWAP) parameters make PHOCS suitable for Raven-class UAVs.

Applications of near-infrared heterodyne remote sensing include environmental and industrial monitoring of gases including carbon monoxide, ammonia, hydrogen chloride, and hydrogen fluoride. Of these, ammonia has the largest commercial potential because ammonia emissions (primarily from agricultural sources) leads to formation of fine particulates (PM2.5) that have serious pulmonary health effects and can nucleate cloud formation (a climate issue). The EPA has constrained ammonia transport across parts of the US midwest and passive remote sensors are ideal for monitoring compliance. Constraints have also been placed on emissions from concentrated animal feed operations(CAFOs)including 900 CAFOs subject to a compliance agreement with the EPA. Monitoring hydrogen fluoride emissions from aluminum smelters and ceramic and brick factories also define a commercial niche for the proposed technology. Large area measurements of carbon monoxide are important for urban areas in which seasonal weather effects drive CO concentrations above safe levels and that can trigger mandatory restrictions on fireplace use.

This is early/mid-stage (TRL 4) — the most realistic path in is NASA SBIR/STTR, which funds small businesses and research institutions to develop technology aligned with NASA's needs (equity-free, phased funding). Check whether a current SBIR/STTR solicitation topic overlaps with this project's technology area, or contact the project directly (above) to ask.

None of these are guaranteed paths for this specific project — TechPort itself doesn't have an "apply" button. Reaching out to the contact(s) above with a specific question is usually the fastest way to find out what's actually open.