GNSS tomography

The development of the tomography method began in the 1930s, with the first applications in medicine, later in seismology, and to study new materials. This method produces two-dimensional distributions and three-dimensional profiles of the studied objects. In the last decade, the method has also been used for remote sensing of the atmosphere. The use for ionospheric monitoring has been described in Chapter 3.3.1. This chapter pays special attention to the use of tomography for tropospheric monitoring. The slant total delays from dense ground-based networks in Germany, France, and Australia are used to demonstrate the three-dimensional structure of water vapor during severe weather events.