**7. References**

Beale, C.M. 2007. The Behavioral Ecology of Disturbance Responses. International Journal of Comparative Psychology 20: 111-120

Beebe, W. 1933. Preliminary Account of Deep Sea Dives in the Bathysphere with Especial Reference to One of 2200 Feet. Proceedings of the National Academy of Sciences of the USA. 1933 January; 19(1): 178–188.

Patrícia Ramos<sup>1</sup> and Nuno Abreu<sup>2</sup>

*Faculty of Engineering of University of Porto*

*Portugal*

**11**

<sup>1</sup>*Institute for Systems and Computer Engineering of Porto (INESC Porto)*

**Autonomous Underwater Vehicle** 

<sup>2</sup>*Institute for Systems and Computer Engineering of Porto (INESC Porto)*

*School of Accounting and Administration of Porto – Polytechnic Institute of Porto*

**Mapping and Dilution Estimation of Wastewater** 

**Discharges Based on Geostatistics Using an** 

Wastewaters are often discharged into coastal waters through outfall diffusers that efficiently dilute effluent and usually restrict any environmental impact within a small area. However, predicting this impact is difficult because of the complexity of the hydrodynamic processes that mix the wastewater and also because of the variability in oceanic conditions. Despite great improvements over the years in the understanding of these mixing processes, since models are now available that can make reasonable predictions under steady-state conditions (Hunt et al., 2010), many aspects remain unknown and unpredictable. For this reason, much effort has been recently devoted to improve ways of monitoring and characterizing sewage plumes

Autonomous Underwater Vehicles (AUVs) have been used efficiently in a wide range of applications. They were first developed with military applications in mind, for example for mine hunting missions. Later on, scientists realized their true potential and started to use them as mobile sensors, taking measurements in difficult scenarios and at a reasonable cost (Bellingham, 1997; Bellingham et al., 1992; Fernandes et al., 2000; Nadis, 1997; Robinson et al., 1999; Yu et al., 2002). MARES (Modular Autonomous Robot for Environment Sampling) AUV has been successfully used to monitor sea outfalls discharges (Abreu et al., 2010; Abreu & Ramos, 2010; Ramos & Abreu, 2010; 2011a;b;c) (see Fig. 1). MARES is 1.5 m long, has a diameter of 8-inch and weighs about 40 kg in air. It features a plastic hull with a dry mid body (for electronics and batteries) and additional rings to accommodate sensors and actuators. Its modular structure simplifies the system's development (the case of adding sensors, for example). It is propelled by two horizontal thrusters located at the rear and two vertical thrusters, one at the front and the other at the rear. This configuration allows for small operational speeds and high maneuverability, including pure vertical motions. It is equipped with an omnidirectional acoustic transducer and an electronic system that allows for long baseline navigation. The vehicle can be programmed to follow predefined trajectories while

**1. Introduction**

**1.1 MARES AUV**

under a variety of oceanographic conditions.

Heezen, B.C. & C.D. Hollister. 1971. The Face of the Deep. Oxford UP, New York.

