JSG T.37

JSG T.37: Theory and methods related to combination of high-resolution topographic/bathymetric models in geodesy

Chair: Daniela Carrion (Italy)
Affiliation:Commission 2 and GGOS

Introduction

Topographic and bathymetric models constitute a fundamental input for geodetic computations, e.g. for the evaluation of terrain effects for local and global geoid estimation. In this regard, the Shuttle Radar Topography Mission (SRTM) provided a very significant contribution to the knowledge of terrain heights over land. Great advantages provided by SRTM are the homogeneity of its spatial resolution and its (almost) global coverage. In addition, the spatial resolution of SRTM is adequate for the majority of geodetic applications. The situation is quite different concerning currently available bathymetric models: in this case, the resolution is not homogeneous around the Earth and the level of accuracy can vary considerably from one area to another. In addition, when considering the transition between land surface and sea bottom, the combination of topographic and bathymetric models can be challenging, due to the limitations linked to resolution and accuracy of data and to local datum inconsistencies, which could be neglected in global models. Different combined products are available at global level, such as SRTM+, however the poor knowledge of the sea bottom or datum issues, may lead to problems in geodetic computations and should be further investigated. Apart from geodetic applications, the precise knowledge of the land-sea transition is crucial for modelling of other environmental processes in the coastal zone, such as the impact of sea level change and extreme sea level events such as storm surges and tsunamis.

This JSG aims at studying the available topographic and bathymetric models and at exploring their limitations, in particular concerning the transition along the coasts.

Objectives

• Highlight the issues of the topography/sea bottom transition through literature examples.
• Analyse available data on global and local topographic and bathymetric models, highlighting the issues, based also on personal research experience.
• Verify the quality of the transition through test cases.
• Suggest best practices for combination of models.
• Identify the need for data acquisition in specific areas.

Program of activities

• Explore available data and literature research.
• Propose review papers concerning the state of the art knowledge on the combination of topographic and bathymetric models.
• Cooperate with IAG Commissions and other JSGs.
• Organize meetings, workshops and sessions at selected conferences, e.g., during Hotine-Marussi 2022.

Membership

Daniela Carrion (Italy), chair
Riccardo Barzaghi (Italy)
Mattia Crespi (Italy)
Vassilios Grigoriadis (Greece)
Karsten Jacobsen (Germany)
Kevin Kelly (US)
Michael Kuhn (Australia)
Cornelis Slobbe (Netherlands)
Roberto Teixeira Luz (Brazil)
Ana Cristina de Matos (Brazil)
Dan Palcu (Brazil)
Ionut Sandric (Romania)
Georgios S. Vergos (Greece)