Zum Stand des Höhenbezugsrahmens in Deutschland

Beitrag zur Entwicklung des Höhenrahmens in Deutschland anläßlich einer Festschrift zum 65. Geburtstag von Prof. Reinhard Dietrich

Improving the Geodetic Infrastructure for Bathymetry and 3D Navigation in the German Exclusive Economic Zone of the North and Baltic Sea

Surveying and navigation became much easier, more accurate and operational thanks to the Global Positioning System. The use of this technology in height determination, bathymetry and 3-D navigation is not only limited by the reduced accuracy compared to the horizontal component. It supposes additional information about the geodetic height reference surface in order to leverage the full potential of this technology. The corresponding models, measurements and activities which are necessary to improve this part of the geodetic infrastructure are usually behind the curtain. This article emphasizes the need of a common cross-border geodetic infrastructure and the relevance of precise models of the height reference surface for GNSS-aided height determinations. The need of gravimetric surveys for the determination and improvement of these models is explained. Finally, it gives an overview about the gravimetric surveys which were carried out in the German Exclusive Zone of the North and Baltic Sea over more than one decade and provides some insight into practical aspects and challenges of this kind of surveys.En un proyecto de dos años de investigación y desarrollo, se desarrolló el prototipo de un servicio en tiempo real basado en GNSS (Sistema Global de Navegación por Satélite) usando un enfoque SSR-RTK (Cinemática en Tiempo Real – Representación del Espacio Nacional) para la zona económica exclusiva alemana en el Mar del Norte. Como el área de levantamientos del Mar del Norte solo se puede representar mediante una distribución heterogénea de Estaciones de Referencia GNSS en Funcionamiento Constante, el algoritmo de cálculo y el modelado de los datos de corrección del GNSS son particularmente importantes. Las mediciones marítimas en el área de levantamientos han confirmado la funcionalidad básica del prototipo hasta casi el 90% de disponibilidad de la determinación de estado RTK con tiempos de inicialización de menos de dos minutos. Se usaron mediciones en tierra y mar además de una estación de control permanente para demostrar los objetivos de calidad.Dans le cadre d’un projet de recherche et développement de deux ans, le prototype d’un service en temps réel basé sur un GNSS (Global Navigation Satellite System) utilisant une approche SSR-RTK (State Space Representation-Real Time Kinema-tic) a été développé pour la zone économique exclusive allemande en mer du Nord. Étant donné que la zone d’étude de la mer du Nord ne peut être représentée qu’avec une distribution hétérogène des stations de référence GNSS en exploitation continue, l’algorithme de calcul et la modélisation des données de correction GNSS sont particulièrement importants. Les mesures à la mer dans la zone d’étude ont confirmé la fonctionnalité de base du prototype grâce à une disponibilité de près de 90% du correctif RTK avec des temps d’initialisation inférieurs à deux minutes. Des mesures en mer et à terre ainsi qu’une station de contrôle permanente ont été utili-sées pour démontrer les objectifs de qualité

The Baltic Sea Chart Datum 2000 (BSCD2000): Implementation of a common reference level in the Baltic Sea

The Baltic Sea Chart Datum 2000 (BSCD2000) is a geodetic reference system adopted for Baltic Sea hydrographic surveying, hydrographic engineering, nautical charts, navigational publications and water level information. It is based on the common geodetic standards for the height system (EVRS) and the spatial reference system (ETRS89) in Europe. In particular, the zero level of BSCD2000 is in accordance with the Normaal Amsterdams Peil (NAP). BSCD2000 is about to be adopted as unified chart datum by all the countries around the Baltic Sea. It agrees with most national height realizations used on land. BSCD2000 will facilitate effective use of GNSS methods like GPS, GLONASS and Galileo for accurate navigation and hydrographic surveying in the future.El Dátum 2000 de la Carta del Mar Báltico (BSCD2000) es un sistema dereferencia geodésico adoptado para los levantamientos hidrográficos del MarBáltico, la ingeniería hidrográfica, las cartas náuticas, las publicaciones náuticas yla información sobre el nivel del mar. Se basa en las normas geodésicas comunespara el sistema de alturas (EVRS) y en el sistema de referencias espaciales(ETRS89) en Europa. En particular, el nivel cero del BSCD2000 está en consonanciacon el Normaal Amsterdams Peil (NAP). El BSCD2000 está a punto de seradoptado como datum de cartas unificado por todos los países que rodean el MarBáltico. Concuerda con la mayoría de las realizaciones de alturas nacionalesutilizadas en tierra. El BSCD2000 facilitará el uso efectivo de los métodos GNSScomo el GPS, GLONASS y Galileo para la navegación precisa y los levantamientoshidrográficos en el futuro.Le Baltic Sea Chart Datum 2000 (BSCD2000) est un système de référencegéodésique adopté pour les levés hydrographiques, l’ingénierie hydrographique,les cartes marines, les publications nautiques et les informations sur le niveau del’eau de la mer Baltique. Il est basé sur les normes géodésiques communes auSystème de Référence Vertical Européen (EVRS) et au Système de RéférenceTerrestre Européen (ETRS89). En particulier, le zéro hydrographique duBSCD2000 est conforme au Normaal Amsterdams Peil (NAP). Le BSCD2000 estsur le point d’être adopté en tant que niveau de référence des cartes commun parl’ensemble des pays bordant la mer Baltique. Il correspond à la plupart desmesures de hauteur nationales utilisées à terre. Le BSCD2000 facilitera l’utilisationefficace des méthodes du GNSS comme le GPS, GLONASS et Galileo pour unenavigation et des levés hydrographiques précis à l’avenir

Lake-level variations of Lago Fagnano, Tierra del Fuego: observations, modelling and interpretation

The lake-level variations of Lago Fagnano, the largest lake in Tierra del Fuego, southernmost South America, on time scales from a few minutes to three years are investigated using a geodetic approach and applying the tools of time series analysis. Based on pressure tide gauge records at three locations in the lake precise lake-level time series are derived. The analysis of the observed variations in space, time and frequency domain leads to the separation of the principal force-response mechanisms. We show that the lake-level variations in Lago Fagnano can be described essentially as a combination of lake-level shift and tilt and of surface seiches. Regarding the lake-level response to air-pressure forcing, a significant departure from the inverse barometer model is found. Surface seiches dynamics are particularly intensive in Lago Fagnano pointing towards exceptionally low dissipative friction. An undisturbed series of seiches lasting eleven days is presented; and at least eleven longitudinal modes are identified. Based on the characterisation of the main contributions in space and time as well as their relation to the driving forces, a model for the transfer of the lake-level variations at a reference point to an arbitrary location in the lake with an accuracy of 1 cm is developed.Facultad de Ciencias Astronómicas y Geofísica

Anomalous ocean load tide signal observed in lake-level variations in Tierra del Fuego

We demonstrate the application of a 100 km long lake as a sensor for studying the tidal effects on Tierra del Fuego main island. The lake-level variations observed in Lago Fagnano reflect both the direct response to the tidal potential and the indirect effect of the ocean tidal loading. Modeling both contributions explains the observed tidal signal in the lake to about 70%. Underestimated model load tide amplitudes are found to be probably responsible for the remaining difference. We interpret this discrepancy as a hint for regional elastic lithosphere properties differing substantially from those represented by currently available global models.Facultad de Ciencias Astronómicas y Geofísica

Lake-level variations of Lago Fagnano, Tierra del Fuego: observations, modelling and interpretation

The lake-level variations of Lago Fagnano, the largest lake in Tierra del Fuego, southernmost South America, on time scales from a few minutes to three years are investigated using a geodetic approach and applying the tools of time series analysis. Based on pressure tide gauge records at three locations in the lake precise lake-level time series are derived. The analysis of the observed variations in space, time and frequency domain leads to the separation of the principal force-response mechanisms. We show that the lake-level variations in Lago Fagnano can be described essentially as a combination of lake-level shift and tilt and of surface seiches. Regarding the lake-level response to air-pressure forcing, a significant departure from the inverse barometer model is found. Surface seiches dynamics are particularly intensive in Lago Fagnano pointing towards exceptionally low dissipative friction. An undisturbed series of seiches lasting eleven days is presented; and at least eleven longitudinal modes are identified. Based on the characterisation of the main contributions in space and time as well as their relation to the driving forces, a model for the transfer of the lake-level variations at a reference point to an arbitrary location in the lake with an accuracy of 1 cm is developed.Facultad de Ciencias Astronómicas y Geofísica

Zum Stand des Höhenbezugsrahmens in Deutschland

Beitrag zur Entwicklung des Höhenrahmens in Deutschland anläßlich einer Festschrift zum 65. Geburtstag von Prof. Reinhard Dietrich