SiPLABoratory

MakaiEX Sea Trial

A first sea trial, the Makai 2005 (for registered participants only) that served as engineering test for the Acoustic Oceanographic Buoy - version 2 (AOB2), took place between September 11 and October 2, 2005, off the Island of Kauai (Hawaii- USA) under the workframe of the HFi-JRP  collaboration with several institutions in Europe and in the US [...more].

RADAR'06 Sea Trial

A second experiment that took place off the west coast of Portugal near the town of Nazare', approximately 60 km north from Lisbon, from July 3rd to July 16th of 2006, as a shared sea trial with the RADAR and the SPOTIWAVE projects. The Portuguese navy vessel NRP Auriga serve as support for the naval operations during the sea trial, namely the equipment deployment and control [...more].

RADAR'07 Sea Trial

A third large scale sea trial, on the Troia area from 9 - 16 July 2007, with the participation of NURC, HLS and NRL as well as the project parterns aboard the portuguese navy ship NRP D. Carlos I. This experiment included network tomography with a field of random AOBs, high-frequency tomography using a fixed vertical array from NURC and underwater communications using both the AOBs and the fixed arrays as receivers. Both low frequency and high frequency sources were used covering 500 Hz - 20 kHz [...more].

AOB2 - final workframe

A final working version of the AOB2 was released by the end of August 2005 and shipped to Hawai for the MakaiEx sea trial.
A detailed explanation of  the actual AOB2 can be found here .
Development of the new AOB

The AOB2 execution project: The new AOB2 is a double shell body with an inner shell in aluminium 5000 containing the electronics and the battery pack in separate containers and an outer protective shell in polythylene plastic. The top cover holds the mast (not represented) and the connectors for accessing the inner features, hydrophone and battery connections, etc... The core system is composed of a PC104+ based system around a Transmeta CPU running Linux and an additional 3Gflop DSP board for data acquisition and online processing. Additional features common to the previous AOB are the Wlan connection, GPS, online 8 hydrophone and 16 thermistor chain sensors. Dimensions are 20 cm outside diammeter and 1.25 m length, total air weight will be around 45 Kg including the array. An additional floating device will be required in order to ensure safe operation at sea. The mast will hold the GPS and Wlan antennas as well as an additional FM antenna for long range and all weather emergency localization and recovery in case of system failure.