Bathymetric Data Acquisition and Navigation: Customer Use Case
INDUSTRY:
Subsea Surveying
CUSTOMER PROFILE:
David Wibowo is a Data Processing Coordinator for Bintang Subsea Indonesia in Jakarta. Bintang Subsea specializes in providing a wide range of bathymetric Surveying, Positioning, Subsea Inspection, and Metocean services using the latest available technology and advanced techniques.
PRODUCT:
Global Mapper Pro
CHALLENGES :
Designing a survey path based on known terrain for the Autonomous Unmanned Surface Vehicle (AUSV) Triton to follow during data collection.
SOLUTION:
Use Global Mapper to integrate maps from multiple sources and projections for 3D visualization and measurement as a basis for survey path planning and post-processing.
The Al Falah Survey
Bintang Subsea Indonesia executes subsea surveys to provide data on the land for field engineers to use in designing underwater construction projects such as pipeline laying, platform placement, or exploration before drilling for oil or gas. For the Al Falah Survey, the Autonomous Unmanned Surface Vehicle (AUSV) Triton surveyed the Red Sea floor to measure slope and morphology, with Global Mapper used in the planning process. The resulting maps were used to determine the best placement for a platform to study oceanographic chemistry in an area of the Red Sea, currents, and many other sensors on the platform. This project provides a glimpse into the seamless fusion of GIS, cutting-edge survey equipment, and maritime navigation systems to achieve unparalleled marine data acquisition and analysis results.
Planning the Survey
The route planning process began with the utilization of Global Mapper to create a comprehensive survey plan by integrating various data sources, including nautical charts, bathymetric data, and other geographic information. Global Mapper was used to transform coordinates and digitize charts, such as PDFs of engineering field drawings. Global Mapper’s extensive list of supported file types and easy georeferencing tool make combining different maps and data into one workspace a simple process. This integration of spatial data allowed for the identification of optimal survey paths that balanced efficient coverage with safety considerations.
“The Global Mapper-enabled route-planning, combined with the incorporation of multibeam data, yielded a comprehensive survey strategy that maximized efficiency, accuracy, and safety.” – David Wibowo, Data Processing Coordinator.
Upon finalization of the survey route in Global Mapper, the next step involved programming the route into the AUSV Triton’s AIS system for the vessel to follow during the survey. The AIS, a vital component of maritime navigation, allows for real-time tracking and communication between vessels, enhancing overall situational awareness and safety. The planned route, informed by Global Mapper’s analysis, was translated into a series of waypoints and geospatial coordinates compatible with the AIS interface.
“Global Mapper [is] a versatile GIS software tool, renowned for its capabilities in geospatial data manipulation and analysis.” – David Wibowo, Data Processing Coordinator.
Executing the Survey
The integration of multibeam bathymetry data was a pivotal aspect of the Al Falah Survey, contributing to high-resolution seafloor mapping. Multibeam echosounders, equipped on the AUSV Triton, emitted multiple sonar beams simultaneously, resulting in detailed bathymetric data collection over a wide swath. The multibeam data provided not only depth information but also insights into seafloor morphology, enabling accurate identification of underwater features such as ridges, valleys, and submerged structures.
Furthermore, the integration of multibeam data into the AIS programming was instrumental in refining the navigation strategy. The high-resolution bathymetric information facilitated route adjustments to avoid potential obstacles and shallow areas, reducing the risk of collisions and ensuring efficient data collection. Additionally, the AIS programming incorporated contingency plans, enabling the AUSV Triton to adapt to changing conditions or unexpected challenges encountered during the survey.
Result
The enriched dataset was used as a basis for determining the best position for a future offshore platform for an oceanography sensor. Global Mapper’s 3D viewer was used to visualize the scanned data for quality control and verification. This allowed old and new data to be overlaid for comparison in a 3D space. The path profile tool was used to visualize the sea bed from a perpendicular perspective to measure slope.
The Al Falah survey conducted by AUSV Triton showcases the synergistic use of advanced geospatial technology, multibeam data, and AIS integration. The Global Mapper-enabled route planning combined with the incorporation of multibeam data yielded a comprehensive survey strategy that maximized efficiency, accuracy, and safety. The resulting AIS programming facilitated real-time navigation and communication, ensuring the successful execution of the survey objectives.
What Can Be Done in Global Mapper Using Bathymetric Data?
Integrating data from multiple sources
Older bathymetric data often comes in without the spatial referencing required to display it in a GIS, such as in the form of paper maps or PDFs. Global Mapper can be used to georeference these maps to allow them to be directly compared to newer spatial datasets. Because Global Mapper supports nearly 400 file formats, this software offers the unique ability to compare and integrate data from just about any source or time. To find additional data, streamable data sources for bathymetric data are available through Global Mapper’s Online Data tool in the Nautical Maps section.
Visualizing 3D Data
To examine bathymetric features and seafloor elevation changes more closely, the Path Profile tool is employed to generate a cross-section of the terrain. Furthermore, the perpendicular Path Profile tool creates parallel cross-section views along the data. This series of cross-sectional views of terrain or point cloud data spaced along a defined path provides the ability to look at subsections of the path profile. Parallel and perpendicular paths can be used to explore sections of terrain data one area at a time. Parallel profiles can be created from single-segment line paths, such as lines with no turns or extra vertices. These paths can also be exported as line features that trace the highest elevation values of the terrain, as shown in the image above. Perspective paths are a great way to export linear terrain data for use in modeling software that can’t handle complex terrain data.
Measuring Changes in the Sea Floor Over Time
If there are multiple datasets of the same area collected at different points in time, they can be compared against each other to map how the landscape changed during that time. Changes in ground elevation can be measured using the Compare Terrain Grid tool in Global Mapper. By subtracting one year’s elevation from another, a new grid can be created in which each cell value represents the elevation difference. In the example below of Anna Maria, Florida, a DEM created in 2017 was subtracted from a DEM created after Hurricane Ian in 2022. Changes in the sea floor elevation are notable. The Compare Terrain tool displays the areas of the data where soil volume increased and decreased at a cell-by-cell scale. Change Detection, as this process is often called, can also be performed between point cloud layers and between point cloud and grid layers.
For more information on the use of Bathymetric data in Global Mapper:
The Surface Under The Water – A Guide To Bathymetric Data In Global Mapper
Bathymetric Data in Global Mapper Overview
GeoTalks Express – Bathymetric Analysis in Global Mapper
WORK MADE EASY WITH GLOBAL MAPPER
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Bathymetric Data Acquisition and Navigation
