Elsevier

Computers & Geosciences

Volume 82, September 2015, Pages 31-37
Computers & Geosciences

Design and implementation of a Data Distribution System for Xiaoqushan Submarine Comprehensive Observation and Marine Equipment Test Platform

https://doi.org/10.1016/j.cageo.2015.05.009Get rights and content

Highlights

  • We design and implement a Data Distribution System for XSCOMETP.

  • The system can acquire, interpret, store and process continuous data in real time.

  • “Hot Swapping” interpretation model guarantees a good scalability.

  • Distinctive characteristics include integration, expandability and independence.

Abstract

One of the major issues concerning undersea observation data is data distribution characterized by multi-disciplinary, multi-parameter and weather-independent continuous observations. It describes the data distribution system for Xiaoqushan Submarine Comprehensive Observation and Marine Equipment Test Platform (XSCOMETP). Based on the design of C/S architecture, the overall system establishes a communication link between the observation infrastructure and the data center using Socket technology. The Data Distribution System for XSCOMETP was developed by C# in the .NET framework, which enabled multi-source and heterogeneous data to be acquired, interpreted and stored in real time. The system can be divided into three functional modules including data acquisition and transmission, data interpretation and storage, and data display. Given the successful trial from August 11, 2013, the data distribution solution proposed in this paper could be a useful reference implementation to the East China Sea Seafloor Observation System.

Introduction

As the third platform to observe the marine (Wang, 2007), seafloor observatory, which enables three-dimensional monitoring from sea surface to the bottom and shifts from an intermittent expeditionary mode to a sustained, in situ experimental mode utterly alters the way to understand the ocean (Clark, 2001). The demand of seafloor observatory comes from seismic monitoring (Sutton et al., 1965), and there were two different sources for the early seafloor observation. One is monitoring the undersea earthquake; another is monitoring the marine environment. In 1978, the Japan Meteorological Agency put the connected seismographs on the bottom of the seafloor to monitor the earthquake, which was the prototype of the seafloor observatory (Suyehiro et al., 2003). While the first ecological monitoring station was established in America, which named Long-term Ecosystem Observatory at 15 m (LEO-15). LEO-15 carried out seafloor observation in 3 km×3 km dimensions, which had recorded sediment transport along and across the coast and the shelf and many biogeochemical processes for years. For instance, two years of wave observation since 1994 recorded 51 sediment transportation events, with 32 of them being caused by winter storm turbulence. Besides, 63% of the events took place in winter (Styles and Glenn, 2005). For another instance, LEO-15 recorded the temperature and Chlorophyll concentration of water column in July, 1997. Clearly, it also recorded the start of upwelling and the rapidly increased productivity consequently in 1999 (Schofield et al., 2002). The Martha's Vineyard Coastal Observatory (MVCO) established since 2001 enables to monitor atmospheric and oceanographic conditions such as wind speed, heat flux, relative humidity, air pressure, solar and infrared radiation, wave parameterization, water temperature, current profiles, tides and salinity. The node architecture was designed to allow simple integration of any sensor by implanting a standard guest port configuration. And a data distribution system has been developed to control the system power distribution and instruments, to monitor the operational status, to log data in real time based on TCP/IP protocol and to process and serve the data to users (Austin et al., 2002, Fredericks et al., 2006). Now the scope of the seafloor observatory have expanded to ecological characterizations, water column studies, upwelling and productivity, organic carbon fluxes, sediment transport, fluids and life in the ocean crust, subduction processes, plate interiors, seismology and magnetics and real-time regional modeling and forecasting (Clark, 2001). NEPTUNE-Canada is now the world's largest deep-sea observation system, with research focusing on five aspects, namely, structure and seismic behavior of the ocean crust, dynamics of hot and cold fluids and gas hydrates in the upper ocean crust and overlying sediments, ocean/climate change and effects on ocean biota/fisheries at all depths, deep-sea sedimentation, ecosystem dynamics and biodiversity, and engineering and computational systems research (Barnes, 2009, Barnes, 2007, Barnes et al., 2007, Li and Xu, 2011). The system has built 5 nodes with a plurality of junction boxes, which have connections with more than 100 sensors and instruments. About 900 raw data files collected in continuous observation are delivered to the laboratory and almost 50 GB compressed data is stored at the University of Victoria in real time per day (Li and Xu, 2011). Therefore, management of massive data in real time is one of the most important aspects of the seafloor observation system.

The Xiaoqushan Coastal Seafloor Observatory, located between 30°31′44″N, 122°15′12″E and 30°31′34″N, 122°14′40″E, was constructed near the Xiaoqushan Island outside the Hangzhou Bay on the inner continental shelf of the East China Sea in April 2009. It was the first seafloor observatory in China and has been running successfully for more than 4 years. This observatory has one junction box connected to three instruments called CTD, OBS, ADCP and transmits over 30 MB data to the data center per day. For the purpose of testing the data acquirement and integration and applications, a preliminary seafloor observation system visualization information system was designed for the Xiaoqushan Seafloor Observatory. The system enables the data receiving, monitoring, management and visualization. The data receiving module fulfills the data reception, decoding, storage in database and management. The information control module is for instrumental status control and data quality control. The two dimensional GIS module finishes GIS functions like the metadata management for the observation data, the query and statistical analysis and so on (Xu et al., 2011). Zhang et al. (2011) first use real-time continuous data recorded by the seafloor observatory to analyze the tsunami induced by the 2010 Chilean earthquake. Such observations are expected to improve tsunami forecast and promote the development of a tsunami warning system and a seafloor observatory network in the East China Sea.

Built upon the success of the Xiaoqushan Seafloor Observatory, we have established a marine equipment test platform since 2011, and developed appropriate specifications through the safety improvement of offshore platform and the general transformation of special junction box. By combining platform and seafloor observation, the submarine comprehensive observatory has been set up. This provides a public sea trial platform for the Shanghai marine advanced technology industry. It is also a test platform for China seafloor observation project and meanwhile will become a new comprehensive observation station to monitor the Shanghai marine environment. A data distribution system is required to acquire, interpret, store and visualize the observation data and so on for XSCOMETP, which promises to provide a good test environment for different marine instruments. The preliminary seafloor observation system visualization information system is designed only for the CTD, OBS, ADCP, so its poor extensibility is unable to meet the needs of the current comprehensive test platform. Therefore designing a data distribution system, which is used for XSCOMETP to acquire, interpret and store data from different instruments and sensors would be a necessity.

From data acquisition, interpretation, storage, management, sharing to modeling, visualization and many other practical applications, the data distribution system for XSCOMETP has already formed a relatively complete data processing chain. The system can acquire and interpret the observed data and various equipment status data, then store them into the database in real time. Meanwhile, the system can acquire data normally and send them to other fixed receiver when instruments equipped on the test platform need to be increased or replaced. As for this problem, the system uses plug-ins to ensure no influence on other interpretation and storage of data when adding or replacing some interpreting methods.

Section snippets

Design of the system

The construction of XSCOMETP and especially the design of the data distribution solution for XSCOMETP will need to consider a series of challenges in order to guarantee the normal operation of the whole submarine comprehensive observation system. These challenges can be summarized below:

  • (1)

    Different kinds of instruments should be tested and their data formats are varied.

  • (2)

    Continuous observation data should be acquired, interpreted, stored and processed in a real-time and efficient way.

  • (3)

    The system

Implementation of the system

Taking all the above software architectures and communication issues into consideration, this paper, which is based on the .NET framework, adopts the C# language and socket class to build the software infrastructure for the data distribution system for XSCOMETP. As a safe, stable and component-oriented programming language, C# combines the simple visual operation of VB and the high efficiency of C++. Socket, used to describe the IP address and port number, is an approach to achieve the TCP/IP

Discussion and conclusion

During the implementation of the data distribution system for XSCOMETP, the functions of data acquisition, interpretation, transmission, storage, management and visual application for various instruments and sensors were integrated into one software platform. The software solves the change of the interpretation process caused by instruments' diversity and variability of Xiaoqushan Submarine Comprehensive Observation and Marine Equipment Test Platform. It can forward the specific data to the

Acknowledgments

The authors wish to thank Chuanlun Zhang from the University of Georgia for his constructive comments while writing this paper; and the authors also feel grateful to other members of our research group and friends for their help in designing and developing the data distribution system for XSCOMETP. The study for this paper was funded by the National High Technology Research and Development Program of China (863 Program) (2012AA09A407), 2011 Research Program of Science and Technology Commission

References (15)

  • T.C. Austin et al.

    A network-based telemetry architecture developed for the Martha's Vineyard Coastal Observatory

    IEEE J. Ocean. Eng.

    (2002)
  • Barnes, C., 2009. Transforming the ocean sciences through cabled observatories. In: Proceedings of the IEEE Aerospace...
  • Barnes, C.R., 2007. Building the world's first regional cabled ocean observatory (NEPTUNE): realities, challenges and...
  • Barnes, C.R., Best, M.M.R., Bornhold, B.D., Juniper, S.K., Pirenne, B., Phibbs, P., 2007. The NEPTUNE Project – a...
  • Clark, H.L., 2001. New seafloor observatory networks in support of ocean science research. In: Proceedings of the...
  • Fredericks, J.J., Groman, R., Hobart, E., Krauspe, J., Allen, J.M., 2006. Martha's vineyard coastal...
  • J. Li et al.

    NEPTUNE-Canada (in Chinese)

    Adv. Earth Sci.

    (2011)
There are more references available in the full text version of this article.
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