Description: In order to address the inevitable need to deploy inexpensive, accurate, reliable sensors that can automatically perform greenhouse gas data collection, the proposed Phase I project builds on the measurement technique described in the paper, "Miniaturized Laser Heterodyne Radiometer for Measurement of Carbon Dioxide CO2 in the Atmospheric Column" by Wilson et al. wherein sunlight is used as the radiometer's signal source. While redesigning the RF receiver in the Mini-Laser Heterodyne Radiometer (Mini-LHR) under a NASA purchase order, Paul Finkel Consulting became familiar with every aspect of the Mini-LHR optical, electrical, software and mechanical design. Along the way, we saw several opportunities to further reduce size and cost, and improve accuracy of the entire system. Likewise, power consumption can be decreased and reliability improved. In the end, the resulting Phase I proof-of-concept system will have fewer moving parts, be lower cost, consume less power –important for solar powered installations – and will be more compact than the original system and have an accuracy better than 0.3%. Most notably, the product of Phase I will serve as a platform to validate further hardware and software improvements that will be incorporated into a commercial version in Phase II.

Benefits: Looking to the very near future, the proposed laser heterodyne radiometer (LHR) could be installed at numerous sites - especially in the arctic where satellite (e.g. GOSAT, OCO-2) data are unavailable – to form a world-wide network capable of making real-time measurements of greenhouse gasses (GHG). Also, the proposed LHR can augment other methods currently used by NASA to measure the abundance of GHG. Also, the LHR lasers can be changed or more can be added to measure other species such as water vapor (H2O) and nitrous oxide (N2O). Further, since sunlight is a very broadband light source, levels of pollutants such as sulfuric acid (H2SO4) and carbon monoxide (CO) if the lasers and optical detector were changed.

One can envision several applications for a low cost, accurate atmosphere radiometer. Any place airborne chemicals need to be detected and/or their concentrations measured, the LHR is a potential solution. Applications could include: ? Measurement of smokestack emissions from the ground. ? Ground-based measurement of airborne jet or rocket engine performance by monitoring exhaust components. ? Detection and classification of harmful airborne gasses or chemicals using a manmade, broadband light source in lieu of sunlight (e.g. monitoring the atmosphere in large factory or in a mine elevator shaft using a stabilized 300 – 2600nm light source). The system can be expanded to simultaneously use multiple lasers to measure species or compounds having spectra that span a wide spectrum.