Development, Deployment, and Validation of a Differential Abospbtion Lidar for Water Vapor Profiling in the Lower Troposphere

蒙大拿州立大学（MSU）的研究人员开发了一种新型的基于二极管激光的差分吸收激光雷达（DIAL），用于对流层低层的水汽廓线。 这种仪器，到目前为止一直是实验室为基础的，利用外腔二极管激光器结合锥形半导体光放大器，以产生一个广泛可调谐的DIAL激光发射器能够访问许多不同强度的水蒸气线。这是第一个基于二极管激光的DIAL仪器，成功地展示了夜间和白天的水汽分布能力，并有可能率先部署具有成本效益的类似设计的传感器网络。 支持的研究将测试和评估一种可现场部署的DIAL仪器的开发，用于在各种地理/气象环境中进行无人值守的长期数据收集。 基于半导体激光器的仪器，其中包括许多具有成本效益的现成组件，将被修改，以在更宽的温度范围内运行。该仪器将部署在三个实地地点，每个地点大约30天收集数据。在这些实地部署期间收集的长期数据集将与现场水汽测量结果进行比较，以进行验证。这项工作的智力价值在于开发一种更复杂和成本效益更高的DIAL仪器，可以部署在地面网络中，用于气候和天气研究和预报应用。雷暴发展），这在很大程度上取决于最接近地球表面的一层大气水蒸气含量的准确知识。 与国家大气研究中心人员的密切合作将加速将开发的技术集成到NSF支持的研究人员可用的仪器套件中。 还将通过直接参与这项工作加强对研究生的培训。

Researchers at Montana State University (MSU) have developed a novel diode-laser-based differential absorption lidar (DIAL) for water vapor profiling in the lower troposphere. This instrument, which until now has been laboratory-based, utilizes external cavity diode lasers in conjunction with a tapered semiconductor optical amplifier to produce a widely tunable DIAL laser transmitter capable of accessing many water vapor lines of varying strength. This is the first diode-laser-based DIAL instrument to successfully demonstrate both nighttime and daytime water vapor profiling capabilities, and has the potential to spearhead cost-effective deployment of networks of similarly-designed sensors. The supported research will test and evaluate development of a field deployable DIAL instruments for unattended long-term data collection in a variety of geographic/meteorological settings. The semiconductor laser-based instrument, which incorporates many cost-effective off-the-shelf components, will be modified to operate over a wider temperature range. The instrument will be deployed at three field sites for data collection on the order of thirty days at each site. The long term data sets collected during these field deployments will be compared with in situ water vapor measurements for validation purposes. The intellectual merit of this effort rests is development of a more sophisticated and cost-effective DIAL instrument that can be deployed in a ground based network for climate and weather research and forecasting applications.Broader impacts of this effort include potential impacts of improved monitoring and forecasting of local and mesoscale weather effects (e.g., thunderstorm development) that are highly dependent on accurate knowledge of atmospheric water vapor content in the layer nearest the earth's surface. Close cooperation with personnel at the National Center for Atmospheric Research will speed integration of developed technologies into the suite of instruments available for NSF-supported researchers. Training of a graduate student will also be enhanced through direct involvement in this effort.