BEGIN:VCALENDAR VERSION:2.0 PRODID:IEEE vTools.Events//EN CALSCALE:GREGORIAN BEGIN:VTIMEZONE TZID:Australia/NSW BEGIN:DAYLIGHT DTSTART:20181007T030000 TZOFFSETFROM:+1000 TZOFFSETTO:+1100 RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=10 TZNAME:AEDT END:DAYLIGHT BEGIN:STANDARD DTSTART:20180401T020000 TZOFFSETFROM:+1100 TZOFFSETTO:+1000 RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4 TZNAME:AEST END:STANDARD END:VTIMEZONE BEGIN:VEVENT DTSTAMP:20180503T000000Z UID:23366E1A-31BF-412D-A2B9-E44F1E4BE2A1 DTSTART;TZID=Australia/NSW:20180411T100000 DTEND;TZID=Australia/NSW:20180411T110000 DESCRIPTION:Distributed underwater sensor networks are an important part of sea monitoring systems. These networks usually include either moored or s eabed sensors and Autonomous Underwater Vehicles (AUVs). In many applicati ons it is desirable to establish communication between operation centres o nshore or in mother-ships to AUV and underwater sensors. Acoustic channels become unreliable at large distances because of reflections near sea bed and increased noise at the surf zone. Use of Unmanned Aerial Vehicles (UAV ) as an element of communication channel permits bringing the transmitter/ receiver closer to the operational area.\n\nMagnetic induction (MI) is a p romising technique that is not affected by multipath propagation and fadin g. Magnetic communication link with frequencies in the ultra-low-frequency (ULF) band features good penetration ability even through salted sea wate r. ULF signals with frequencies in the range of 0.3 – 3 kHz feature skin effect depth values of about 4 – 13 m for sea water\, and data rates ra nge from several to hundreds bits per second. Thus\, the ULF band seems as a reasonable tradeoff between penetration ability and data rate.\n\nMagne tic communication is based on the magnetic coupling between a transmitting coil antenna and a receiver - search-coil magnetometer.\n\nWe investigate 1) downlink enabling to send commands and data from UAV to an AUV and und erwater sensors performing an in situ undersea monitoring\; 2) underwater- to-air communication up-link. The airborne transmitter comprises an air co re coil excited by a low frequency alternating current which is modulated according to the transmitted binary data. The underwater receiver is based on a search-coil magnetometer which detects the received signal and demod ulates the data.\n\nThe present work includes analysis of the communicatio n link. Simulation of the low frequency magnetic field produced by magneti c moment and its interaction with the conductive media is performed. Some engineering aspects of receiver/transmitter installation are considered. W e also estimate the link’s budget\, considering receiver sensitivity\, t ransmitter magnetic moment\, and channel attenuation. The attenuation is c alculated using a computer model including seabed-water and air-water inte rfaces.\n\nCo-sponsored by: Prof. Subhas Mukhopadhyay\n\nSpeaker(s): Boris Ginzburg <bginzburg@gmail.com>\, \n\nBldg: E6B 149\, Macquarie University \, Sydney\, New South Wales\, Australia\, 2109 LOCATION:Bldg: E6B 149\, Macquarie University\, Sydney\, New South Wales\, Australia\, 2109 ORGANIZER:Subhas.Mukhopadhyay@mq.edu.au SEQUENCE:3 SUMMARY:Air-Underwater Magnetic Communication Link URL;VALUE=URI:https://events.vtools.ieee.org/m/169705 X-ALT-DESC:Description: <br /><p>Distributed underwater sensor networks are an important part of sea monitoring systems. These networks usually inclu de either moored or seabed sensors and Autonomous Underwater Vehicles (AUV s). In many applications it is desirable to establish communication betwee n operation centres onshore or in mother-ships to AUV and underwater senso rs.&nbsp\; Acoustic channels become unreliable at large distances because of reflections near sea bed and increased noise at the surf zone.&nbsp\; U se of Unmanned Aerial Vehicles (UAV) as an element of communication channe l permits bringing the transmitter/receiver closer to the operational area .</p>\n<p>Magnetic induction (MI) is a promising technique that is not aff ected by multipath propagation and fading. Magnetic communication link wit h frequencies in the ultra-low-frequency (ULF) band features good penetrat ion ability even through salted sea water. ULF signals with frequencies in the range of 0.3 &ndash\; 3 kHz feature skin effect depth values of about 4 &ndash\; 13 m for sea water\, and data rates range from several to hund reds bits per second. Thus\, the ULF band seems as a reasonable tradeoff b etween penetration ability and data rate.</p>\n<p>Magnetic communication i s based on the magnetic coupling between a transmitting coil antenna and a receiver - search-coil magnetometer.</p>\n<p>We investigate 1) downlink e nabling to send commands and data from UAV to an AUV and underwater sensor s performing an in situ undersea monitoring\; 2) underwater-to-air communi cation up-link. The airborne transmitter comprises an air core coil excite d by a low frequency alternating current which is modulated according to t he transmitted binary data. The underwater receiver is based on a search-c oil magnetometer which detects the received signal and demodulates the dat a.</p>\n<p>The present work includes analysis of the communication link. S imulation of the low frequency magnetic field produced by magnetic moment and its interaction with the conductive media is performed. Some engineeri ng aspects of receiver/transmitter installation are considered. We also es timate the link&rsquo\;s budget\, considering receiver sensitivity\, trans mitter magnetic moment\, and channel attenuation. The attenuation is calcu lated using a computer model including seabed-water and air-water interfac es.</p> END:VEVENT END:VCALENDAR