Feasibility study of a total precipitable water IPDA lidar from a solar-powered stratospheric aircraft

Repetitive, high spatial resolution measurements of water vapor are highly desirable for a range of critical applications, including quantitative forecasts of wildfire risk forecasting, extreme weather, drought implicated in mass refugee dislocation, and air quality. A point design for an integrated path differential absorption (IPDA) light detection and ranging (lidar) for column precipitable water vapor (PWV) intended for high-altitude long-endurance (HALE) uncrewed aerial systems (UASs) is described and analyzed. A novel, to the best of our knowledge, all-semiconductor source utilizing an intensity-modulated continuous wave approach to ranging is proposed, which facilitates reductions in weight, power, and size. Analytic and Monte Carlo calculations suggest that high spatial resolution (<10 m) or high precision (<1%) may be obtained.