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The original Odyssey vehicle systems established a style of platform that has proven to he extremely versatile and useful for a variety of scientific missions. The Monterey Bay Aquarium Research Institute (MBARI) has carried forward the Odyssey design, now called Dorado.Dorado is a mid-sized vehicle in comparison to other AUV systems. Dorado vehicles are 0.5334 m (21") diameter, and are designed for deep water (4500 m) operation.The Dorado design improves upon the original Odyssey versatility by dividing the vehicle up into modular sections. Specific sections can then he built to carry out each type of mission. A Dorado vehicle can then consist of a nose section, one or several mission-specific midbodies, and a tail section. The main vehicle systems for propulsion, control, data handling, navigation, acoustic sub-systems, and most other standard functions are housed in the tail section. This paper introduces the history of the Dorado systems. and what has been accomplished to date. This paper further describes the various architectural concepts and operational results. Future planning is also discussed. 1. INTRODUCTION MBARl is in its sixth year of building and operating AUVs. The engineers and scientists leamed many lessons from numerous sea trials and a few scientific oceanographic missions. Ln the fall of 2000, MBARl deployed Odyssey 1Ib AUVs from the RV Point Sur during the MBARI UpperWater-Column Science Experiment (MUSE) cruise. The vehicles, mainly built by the Massachusetts Institute of Technology (MIT) Sea Grant Laboratory, camed silver-zinc rechargeable batteries for energy storage, a PCI104 stack of boards for a main vehicle computer, a CTD, Bathyphotometer. and a forward looking sonar. The software was written and designed at MBARI and deployed initially on these vehicles. The object-oriented, CORBA-like software was a successful improvement over the original singlethreaded code from MIT [I]. Missions over the past several years have proven it to he extremely robust.. The most recent vehicle that brought in lessons leamed was called the Atlantic Layer Tracking Experiment (ALTEX) vehicle [23. It was a Dorado class AUV which was deployed in the Arctic Ocean near Spitzbergen in October 2001 to measure ice thickness and perform mid-water analysis and data collection [3]. When the original ALTEX AUV was designed, modularity was a key component. The ability to swap out different energy sections, instrument payload sections, and data transfer sections was a requirement for testing the ALTEX vehicle over the years of development. The Dorado class of AUVs was the result of this design effort. Other institutions such as Florida Atlantic University recognized the need for modular AUVs. Their Ocean Explorer class of AUVs address the requirement of modularity. Scientists wanting to integrate a payload on one of those vehicles are given a simple electrical and mechanical interface specification. This approach is the same for Dorado. MBARI is directing its development efforts to create new technologies for AUVs such...

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The Monterey Bay Aquarium Research Institute (MBARI) is developing an autonomous seafloor mapping capability for deep ocean science applications. The MBARI Mapping AUV is a 0.53 m (21 in) diameter, 5.1 m (16.7 fl) long, Dorado-class vehicle designed to carry four mapping sonars. The primary sensor is a 200 kHz multibeam sonar producing swath bathymetry and sidescan. In addition, the vehicle carries 100 kHz and 410 kHz chirp sidescan sonars, and a 2-16 kHz sweep chirp subbottom profiler. Navigation and attitude data are obtained from an inertial navigation system (INS) incorporating a ring laser gyro and a 300 kHz Doppler velocity log (DVL). The vehicle also includes acoustic modem, ultra-short baseline navigation, and long-baseline navigation systems. A single cylindrical pressure housing contains all of the mapping sonar electronics, and the main vehicle control and acoustic communications electronics are housed in a separate glass ball. The Mapping AUV is powered by three 2 kWhr Li-polymer batteries, providing an expected mission duration of 12 hours at a typical speed of 1.5 mls. The assembled package i s rated to 6000 m depth, allowing MBARI to conduct high-resolution mapping of the deepocean seafloor. Initial atsea testing commenced in May 2004 using the subbottom profiler and 100 kHz sidescan. The sonar package will also be mountable on ROV Ventana, allowing surveys at altitudes e 10 m at topographically challenging sites. The MBARI Seafloor Mapping team is now working towards integration of the multibeam sonar and towards achieving regular operations during 2005.

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