The International Hydrographic Organization on Hydrographic Capabilites

The International Hydrographic Organization on Hydrographic Capabilites

According to the statistics maintained by the International Hydrographic Organization, over 50 percent of the world’s coastal waters have never been surveyed. However, there are many users who require current high-quality bathymetric information for this zone, highlighting the need to fill this data gap.

The Satellite-Derived Bathymetry (SDB) technology helps to address this challenge. Initially established as a reconnaissance tool for shallow water bathymetry only, cutting-edge SDB techniques are increasingly used as a cost-efficient and rapid survey method for acquiring high-resolution bathymetric data down to water depths of 30 meters.

The use of this technology in applications such as safety of navigation, reconnaissance surveys, coastal zone management and hydrodynamic modeling is increasing significantly, and there is therefore a compelling need to discuss current technological capabilities, application requirements and suitable quality standards of SDB data.

To learn more about the International Hydrographic Organization objectives, please read the interview with Dr. Mathias Jonas, Secretary General of the IHO here.

Satellite-Derived Bathymetry for Coastal Monitoring Solutions

Satellite-Derived Bathymetry for Coastal Monitoring Solutions

By EOMAP

Coastal zones represent some of the most densely populated regions of the world and are under increasing pressure from man-made activities. Coastal zones are highly dynamic (Syvitski et al. 2005) and are subject to change in the short term for example changes caused by extreme weather events and long term for example changes caused by erosion and currents. Offshore and coastal engineering activities can modify coastal landscapes significantly, and man-made disasters can have dramatic impacts on the coastal environment. All these changes create a high demand for spatial and environmental data to aid in coastal zone management.

A consistent spatial framework is necessary and challenging, especially because the continually shifting land–water interface poses significant logistical problems for mapping (Committee on National Needs for Coastal Mapping and Charting 2004). The extremely dynamic nature of coastal marine
environments makes it especially difficult to monitor. Important issues in coastal monitoring include water characterization, observations of water-quality trends over time, identification of emerging problems, and information for pollution prevention and emergency response (Siermann et al. 2014).

Satellite-Derived Bathymetry

The greatest demand is for up-to-date shallow bathymetric data (Committee on National Needs for Coastal Mapping and Charting 2004) to provide the fundamental geospatial framework which is essential for navigation, port and offshore construction, security, coastal zone management, fisheries management, coasta lrestoration, and tourism.

Vessel- and aircraft-based methods for coastal monitoring surveys can be cost and time consuming, depending on the level of detail required. For these reasons, extended areas of water worldwide are not mapped in detail, or existing data may be out of date, especially in dynamic environments. The demand for bathymetric data is therefore obvious and lack of this data causes risk to navigation and concerns to the offshore industry and beyond.

The value-added services provided by satellite images can increasingly contribute to fill geospatial data gaps and support continuous monitoring.

 

SDB Day 2018 – Satellite-Derived Bathymetry Technology and User Forum

The first international conference on Satellite-Derived Bathymetry (SDB Day 2018) is now open for registration to discuss key issues on capabilities, data integration and quality standards. The Satellite-Derived Bathymetry Technology and User Forum will be held on June 6 and 7, 2018 in the Bavarian Lake District near Munich, Germany.

For more information and to register for the conference, please visit www.sdbday.org.

References:

Committee on National Needs for Coastal Mapping and Charting, Mapping Science Committee, National Research Council. 2004.
A Geospatial Framework for the Coastal Zone: National Needs for Coastal Mapping and Charting. Washington, DC: National Academies Press.
Syvitski, J., N. Harvey, E. Wolanski, W. Burnett, G. Perillo, V. Gornitz, R. Arthurton, H. Bokuniewicz, J. Campbell, L. Cooper, K. Dunton, S. Gao, P. Hesp, Y. Saito, J. Salisbury, M. Snoussi, and W. Yim. 2005. “Dynamics of the Coastal Zone.” In Coastal Fluxes in the Anthropocene, edited by C. Crossland,
H. Kremer, H. Lindeboom, C. Marshall, C. Le Tissier, and D. Martin. Berlin: Springer. doi:10.1007/3-540-27851-6_2.
Siermann, J., C. Harvey, G. Morgan, and T. Heege. 2014. “Satellite Derived Bathymetry and Digital Elevation Models (DEM).” International Petroleum Technology Conference, Kuala Lumpur, Malaysia, December 10–12. doi:10.2523/17346-MS

Effective Surveying Tool for Shallow-water Zones

Effective Surveying Tool for Shallow-water Zones: Satellite-derived Bathymetry

By Dr. Thomas Heege, Dr. Knut Hartmann, Dr. Magnus Wettle

January 5, 2017

A recent article provides an overview of satellite-derived bathymetry methods and how data can be integrated into survey campaigns, and showcases three use cases. Bathymetric data in shallow-water zones is of increasing importance to support various applications such as safety of navigation, reconnaissance surveys, coastal zone management or hydrodynamic modelling. A gap was identified between data demand, costs and the ability to map with ship and airborne sensors. This has led to the rise of a new tool to map shallow-water bathymetry using multispectral satellite image data, widely known as satellite-derived bathymetry (SDB).

Strictly speaking, the methods to derive information on seafloor topography using reflected sunlight date back to the 1970s but it has required iterative improvements of algorithms, computational power, satellite sensors and processing workflows to provide the current state of the art tool. Today, a range of different methods exist under the umbrella of the SDB term. However, as with traditional survey methods, it is imperative to understand the advantages, disadvantages and overall feasibility in order to evaluate the suitability and fit-for-purpose of a given SDB application.

Bathymetric Data Production using Optical Satellite Imagery

Historically, empirical methods were used, which require known depth information over the study area. By comparing these known depths with the satellite signal, a statistical relationship can be derived that adequately describes depth as a function of the signal. Aside from requiring known depth data, these methods will only work for a given satellite image. A subsequent satellite scene, even of the same location, may contain different atmospheric and in-water parameters, and thus the statistical relationship needs to be re-calculated.

To learn more, please read on EOMAP on Satellite Derived Bathymetry.