Legislative Documents

Also, variously referred to as: House bills; House documents; House legislative documents; legislative documents; General Court documents

Wie Friedrich Robert Helmert die Wissenschaftsdisziplin Geodäsie prägte

Friedrich Robert Helmert wurde am 31. Juli 1843 in Freiberg/Sachsen geboren. Früh zeigte sich Helmerts Begabung mit Zahlen, Geometrie und Technik umzugehen. An der Königlichen Polytechnischen Schule, der Vorgängereinrichtung der heutigen Technischen Universität Dresden, entwickelte sich bei Helmert rasch eine Neigung zur Geodäsie, die von seinem Lehrer, Prof. Christian August Nagel (1821-1903), erkannt und gefördert wurde

Definition and Proposed Realization of the International Height Reference System (IHRS)

Studying, understanding and modelling global change require geodetic reference frames with an order of accuracy higher than the magnitude of the effects to be actually studied and with high consistency and reliability worldwide. The International Association of Geodesy, taking care of providing a precise geodetic infrastructure for monitoring the Earth system, promotes the implementation of an integrated global geodetic reference frame that provides a reliable frame for consistent analysis and modelling of global phenomena and processes affecting the Earthâ\u80\u99s gravity field, the Earthâ\u80\u99s surface geometry and the Earthâ\u80\u99s rotation. The definition, realization, maintenance and wide utilization of the International Terrestrial Reference System guarantee a globally unified geometric reference frame with an accuracy at the millimetre level. An equivalent high-precision global physical reference frame that supports the reliable description of changes in the Earthâ\u80\u99s gravity field (such as sea level variations, mass displacements, processes associated with geophysical fluids) is missing. This paper addresses the theoretical foundations supporting the implementation of such a physical reference surface in terms of an International Height Reference System and provides guidance for the coming activities required for the practical and sustainable realization of this system. Based on conceptual approaches of physical geodesy, the requirements for a unified global height reference system are derived. In accordance with the practice, its realization as the International Height Reference Frame is designed. Further steps for the implementation are also proposed

Development of a European Combined Geodetic Network (ECGN)

To ensure the long-time stability of the terrestrial reference system with an accuracy of 10‑9 in the global and continental scale, the interactions between different time-dependent influences of the system Earth to the terrestrial reference system and the related observation has to be considered in the evaluation models. It is proposed to establish a kinematic European Combined Geodetic Network (ECGN) and to integrate the spatial and height reference system into the Earth gravity field parameter estimation. This plan is in agreement with the foreseen IAG project of an Integrated Global Geodetic Observation System (IGGOS). In selected European stations ECGN will establish the combination of time series of spatial/geometric GNSS observations, precise levelling and tide gauge records with gravity field related observations (gravity, Earth tides). Observations are complemented with meteorological parameters, surrounding information of the stations, e.g. eccentricities and ground water level. A first call for participation in the project was directed to the implementation of the ECGN stations. These stations include the standard observation techniques GNSS (GPS/GLONASS—permanent), gravity (super conducting gravimeter and/or absolute gravimeter—permanent or repeated), levelling connections to nodal points of the European levelling network (UELN) (repeated) and meteorological parameters (permanent). A basic constituent of the ECGN stations is a local network for controlling the eccentricities at the 1 mm accuracy level in all three spatial components. For the contributing observation techniques, guidelines have been agreed upon to ensure equal observation principle