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.