Consistent height transformations between geodetic and meteorologic reference systems

Author: T. Hobiger, David Salstein and et al.
December 3, 2012
Poster presentation
AGU Fall Meeting 2012

Thomas Hobiger; Johannes Boehm; Jean-Paul Boy; James H. Foster; Pascal Gegout; Rüdiger Haas; Ryuichi Ichikawa; Daniel S. MacMillan; Shang-Guan Ming; Arthur E. Niell; Felipe G. Nievinski; Maaria Nordman; David A. Salstein; Marcelo C. Santos; Michael Schindelegger; Tonie M. van Dam; Henrik Vedel; Jens Wickert; Florian Zus (2012) Consistent height transformations between geodetic and meteorologic reference systems. AGU Fall Meeting 2012, San Francisco, CA.

Numerical weather models (NWMs) contain valuable information that is relevant for removing the environmental signal from geodetic data. Currently no clear documentation exists regarding how to deal with the coordinate systems when carrying out the calculations in a geodetic reference frame. A "conventional" transformation model (available also as source code) would enable geodesists to handle such data easily and allow them to use data from different meteorologic data-sets. In addition, geodetic products such as GNSS derived zenith total delays are being assimilated into NWMs. Thus, the transformations that convert the meteorological data into a geodetic reference frame should also support the use of geodetic data in meteorological models. The IAG Intercomission Committee on Theory - Special Study Group 12 “Coordinate systems in numerical weather models” has been set-up to 1) deal with the differences between geodetic and meteorologic reference systems and 2) provide consistent models for transforming between the two systems. We present the first product from this effort: a conventional height transformation that transforms between ellipsoidal heights and the various height systems used in NWMs. We will discuss the choice of the gravity model, which is crucial for such a transformation, and we will present the final model that the study group believes best describes the transformation in an unambiguous and bi-directional sense.