LIDAR Technology for measuring trace gases on Mars and Earth

摘要

Many fundamental questions about planetary evolution require monitoring of the planet's atmosphere with unprecedented accuracy at both high and low latitudes, over both day and night and all seasons. Each planetary atmosphere presents its own unique challenges. For the planets/moons that have relatively low surface pressure and low trace gas concentrations, such as Mars or Europa, the challenge is to have enough sensitivity to measure the trace gas of interest. For Earth, the challenge is to measure trace gases with very high precision and accuracy in the presence of other interfering species. An orbiting laser remote sensing instrument is capable of measuring trace gases on a global scale with unprecedented accuracy, and higher spatial resolution that can be obtained by passive instruments. For Mars, our proposed measurement uses Optical Parametric Amplifiers (OPA) and Integrated Path Differential Absorption (IDPA) in the 3-4 um spectral range to map various trace gas concentrations from orbit on a global scale. For earth, we propose to use Erbium Doped Fiber Amplifier technology (EDFA) and IDPA at 1.57 and OPA at 1.65 urn to measure carbon dioxide and methane concentrations respectively.