Search

The management of sensor nodes on the sea floor represents an important challenge due to the high difficulties associated to the deployment and recovering of untethered instruments on the seafloor. These difficulties are not only related to the management of the instruments themselves but also related to the valuable information that can be lost. Ambient sound and interferences, maritime traffic, marine mammals behavior, oceanographic data are all among this critical information suitable to be registered. The fact of part of these information being missed, represent a void gap in the spatio-temporal identification phenomena analysis. For reducing the risk of losing information and with the aim of providing a feasible and low cost systems for recovering information from seafloor, a hybrid glider vehicle equipped with acoustic and laser optical communications is proposed. Preliminary studies as well as experimental results of optical/acoustic communications integrated in the hybrid glider Alba14 as data mule are presented.

AUVs are self-propelled and able to navigate at an acceptable speed, but they need an electric motor and batteries that are limited in autonomy. Multivehicle fleet deployment can provide an adequate platform for conducting long term surveillance. Unexpected event detection can be more easily conducted if a set of vehicles in idle mode are expecting the occurrence of this event. Long term and high persistence are very interesting characteristics that a collaborative fleet of different vehicles can provide. However, the problem is the high cost of such kind of vehicles. The possibility of performing adequate tasks by using low cost underwater vehicle could multiply the number of agents in the area and therefore, providing high persistence and wide survey area capabilities. This paper progresses in the definition of the requirements needed to be applied on these kind of vehicles considering the low cost of construction and operation as one of the main goals. A more technological advanced and better equipped ASV as communication and coordination station in the area in combination with a fleet of robust Low Cost AUVs in collaborative schema seems to be an interesting platform for providing good results.

The challenge of extending the autonomy in AUV deployments is one of the most important issues in oceanographic research today. The possibility of maintaining a team of AUV under deployment in a defined area of interest for a long period could provide an additional source of information [8]. All this data in combination with the measures provided by buoys and sea gliders used for slow motion and long range operations will be very valuable. A group of low cost AUV's in alternative automatic switching system navigation-charging operation, could allow a kind of continuous surveying operation. This work is the continuation of the ideas that some of the authors previously presented in the AUV 2010 conference at MBARI [8]. At this conference was proposed the great interest for researching oceanic processes on two areas near Cartagena, Spain: cape Tiñoso and the Mar Menor a shallow coastal lagoon. Both areas require a different research structure configuration because of their opposite characteristics. The Mar Menor is a shallow salty lagoon 20 miles long with 7 m of maximum depth and particular features. This lagoon seems to present a sort of oceanic behavior and can be compared with the major oceans but a minor scale. The second area considered is cape Tiñoso, a very deep area in the Mediterranean Sea where the presence of a self-break provides an interesting potential for the research of the effect of upwelling currents., This work has been partly supported by the Spanish Ministry of Education under projects number TIN2011-28435-C03-01 and CTM2011-29691-C02-01.