This paper describes the concept, the technical implementation and the practical application of a miniaturized sensor system integrated into an autonomous underwater vehicle (AUV) for real-time acquisition of water quality parameters. The main application field of the presented system is the analysis of the discharge of nitrates into Norwegian fjords near aqua farms. The presented system was developed within the research project SALMON (Sea Water Quality Monitoring and Management) over a three-year period. The development of the sensor system for water quality parameters represented a significant challenge for the research group, as it was to be integrated in the payload unit of the autonomous underwater vehicle in compliance with the underwater environmental conditions. The German company -4H- JENA engineering GmbH (4HJE), with experience in optical in situ-detection of nutrients, designed and built the measurement system. As a carrier platform, the remotely operated vehicle (ROV) “CWolf” from Fraunhofer-Institut für Optronik, Systemtechnik und Bildauswertung - Institutsteil Angewandte Systemtechnik (IOSB-AST) modified to an AUV was deployed. The concept presented illustrates how the measurement system can be integrated easily into the vehicle with a minimum of hard- and software technical interfaces.

Recently, underwater vehicles have become low cost, reliable and affordable platforms for performing various underwater tasks. While many aquaculture systems are closed with no harmful output, open net cage fish farms and land-based fish farms can discharge significant amounts of wastewater containing nutrients, chemicals, and pharmaceuticals that impact on the surrounding environment. Although aquaculture development has often occurred outside a regulatory framework, government oversight is increasingly common at both the seafood quality control level, and at baseline initiatives addressing the basic problem of pollution generated by culture operations, e.g. the European marine and maritime directives. This requires regular, sustainable and cost-effective monitoring of the water quality. Such monitoring needs devices to detect the water quality in a large sea area at different depths in real time. This paper presents a concept for a guidance system for a carrier (an autonomous underwater vehicle) of such devices for the automated detection and analysis of water quality parameters

The sustained and cost-effective monitoring of the water quality within European coastal areas is of growing importance in view of the upcoming European marine and maritime directives, i.e. the increased industrial use of the marine environment. Such monitoring needs mechanisms/systems to detect the water quality in a large sea area at different depths in real time. This paper presents a system for the automated detection and analysis of water quality parameters using an autonomous underwater vehicle. The analysis of discharge of nitrate into Norwegian fjords near aqua farms is one of the main application fields of this AUV system. As carrier platform the AUV "CWolf" from the Fraunhofer IOSB-AST will be used, which is perfectly suited through its modular payload concept. The mission task and the integration of the payload unit which includes the sensor module, the scientific and measurement computer in the AUV carrier platform will be described. Few practice oriented information about the software and interface concept, the function of the several software modules and the test platform with the several test levels to test every module will be discussed.

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Long-range autonomous underwater vehicles (AUVs) need a higher degree of autonomy than short-range vehicles. That results from the limited communication possibilities during the mission execution -AUVs are out of communication range of a supporting vessel almost the whole time. There is no way to transfer a new mission plan into to a vehicle or to command a surface maneuver.That's why the mission management system as the top level in the software architecture of an AUV is the key component for enabling complete antonomnns operations. It has to observe the vehicle and environment conditions and to modify the mission plan given by an operator during mission preparation if the mission execution is endangered. This paper presents a hybrid mission management system consisting of several modules responsible for different tasks. Mission Monitoring observes the execution ofthe mission plan and initiates a replanning if necessary. Mission Replanning is responsible for insertion, deletion and optimization of the involved maneuvers. As third module, the Chart Server checks the modified plan against a digital chart and modifies a route if a ground collision would occur.Preliminary simulation results of the optimization and the other modification methods conclude the paper.