Open-Path, Cavity-Enhanced Absorption System for Rapid Measurements of Water Vapor and Temperature Aboard an UAS

The Earth and Environmental Systems Sciences Division (EESSD) of DOE’s Office of Biological and Environmental Research (BER) aims to better predict the Earth system on seasonal to multidecadal time scales to inform domestic policy. As part of this mission, one of EESSD’s grand challenges is to explore the drivers and responses in the Earth system. In response to this challenge, DOE is researching clouds and their impact on the global climate. In order to understand cloud growth, dynamics, and the impact of warming, researchers need to make very rapid, in situ measurements of water vapor concentration and temperature in the supersaturated regions in clouds. In this Small Business Innovative Research (SBIR) program, Nikira Labs Inc. proposes to develop, deploy, and deliver multiple compact, lightweight analyzers for very rapid, in-situ monitoring of water vapor concentration ([H2O]) and air temperature (T) aboard airborne platforms. The analyzers will use multipass tunable diode laser absorption spectroscopy to make real-time, first-principles measurements of both parameters at the millisecond timescale with no memory effects. The resulting systems will be utilized by the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research facility to study supersaturation and better understand cloud dynamics. In Phase I, Nikira Labs Inc. will select a measurement strategy based on spectral modeling and fabricate a small (25 cm x 20 cm x 20 cm), lightweight (< 5 kg) prototype unit capable of accurately and rapidly (100 Hz) measuring [H2O] and T over the ranges expected for 0 – 5000 meters altitude. The instrument will be extensively laboratory tested to determine its accuracy, precision, linearity, dynamic range, time response, and immunity to vibration and pressure changes. Subsequent to this testing, Nikira Labs will deploy the sensor for both terrestrial and airborne sensing in benign and foggy environments. Finally, the Phase I results will be used to design a series of Phase II instruments suitable for integration into a variety of DOE unmanned aerial systems (UASs), including the ArcticShark and tethered balloons. In addition to its value in studying climate change feedbacks, the SBIR instrument can readily be reconfigured to measure sticky and reactive gases like ammonia for environmental and semiconductor applications. As discussed in detail in the Phase I Commercialization Plan, Nikira Labs Inc. anticipates a cumulative sales revenue of $44.6M during the first 10 years of commercialization for these two markets alone.