Development of a tomographic water vapour sounding system based on GNSS data

介绍了德国GPS水汽反演系统的研制情况。从GPS数据中提取的湿度信息用于重建空间分辨的水汽分布。这种湿度数据在气象学和地球科学的各个领域都是必不可少的，例如，天气预报、减灾和水管理。在第一个项目期间，开发并验证了从大约270个德国全球定位系统地面站获得视线（倾斜）大气延迟数据的先进技术。几个层析重建技术已经实施和测试。在第二阶段，应进行广泛的审定和核查研究。重建的湿度场将与无线电探空仪廓线和水汽辐射计数据等气象观测数据以及数值天气模式场进行比较。GPS观测提供的信息将被估计，并与重建的湿度场的误差有关。这些信息的组合将被用来估计与重建的错误质量。在验证研究的同时，将进一步改进和优化数据处理和断层扫描的所有步骤。

The development of a GPS water vapour retrieval system for Germany is described. The humidity information as extracted from GPS data is used to reconstruct spatially resolved water vapour distributions. Such moisture data are essential in various fields of meteorology and geoscience, e.g., weather forecast, hazard mitigation and water management. In the first project period advanced techniques for the derivation of line-of-sight (slant) atmospheric delay data from about 270 German GPS ground stations have been developed and validated. Several tomographic reconstruction techniques have been implemented and tested. In the second period extensive validation and verification studies shall be carried out. The reconstructed humidity field will be compared with meteorological observations such as radiosonde profiles and water vapour radiometer data and with numerical weather model fields as well. The information provided by the GPS observations will be estimated and related to the error of the reconstructed humidity field. A combination of these information will be used to estimate the error quality together with the reconstruction. In parallel to the validation studies all steps of the data processing and tomography will be further improved and optimized.