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Data acquisition with the PAR sensor worked fawlessly. As it was a day with scattered clouds, the PAR diagram showed the expected spikes and dips, with a smooth decline towards the evening. Nevertheless, due to the polar day, the PAR values remained relatively stable throughout the day. Future Prospects The hexacopter is a platform that could be useful to all kinds of experiments. By marking the ice edge and conducting PAR measurements, expedition ARK-XXVII/2 demonstrated only one way that marine operations could beneft from fying drones. The plan is to enlarge the working range of the hexacopter signifcantly with, for instance, cameracontrolled fights, improved communication abilities and more autonomy via an automatic homing system. At least for 2013, the scientifc payload will remain the same. However, the type of PAR sensor will be changed from one with logarithmic output to a sensor with linear output (Satlantic���s PAR-LIN-S). Within the range of the measured PAR values, which were relatively high on the surface of the ice, a linear sensor offers a higher resolution, whereas a logarithmic PAR sensor is used on AWI���s AUV to make use of its high resolution at low PAR values. Additionally, since PAR sensors are equipped with a cosine collector, the inclination of the hexacopter with respect to the sun is important. Especially as the hexacopter is operated in high latitudes where the sun remains low above the horizon, the resulting error caused by a tilted and moving sensor, for example, due to waves under the ice, is relatively big. To correct the data, the inclination angles of the hexa- copter (taken from its gyro) and its orientation (using the compass) will be logged in the future. Acknowledgments The authors would like to thank Kimberly Shurn of Bluefn Robotics for her valuable assistance in feeding the signals of various GPS transmitters into Bluefn���s AUV Dashboard control software. References For a list of references, contact Sascha Lehmenhecker at sascha.lehmenhecker@awi.de. n Sascha Lehmenhecker is a member of the deep-sea research group at the Alfred Wegener Institute. He is a computer science engineer with special training in electronics, and specializes in microcontroller applications and circuit design. He has a bachelor���s degree from the University of Applied Sciences in Bremerhaven, Germany. Thorben Wulff is a Ph.D. student at the Alfred Wegener Institute. He has a bachelor���s and master���s in mechanical engineering, both from the University of Applied Sciences in Mannheim, Germany. Funded by the European Union in the frame of project EUROFLEETS, he is working on interoperable payloads for European AUVs. ���Fishers make the most powerful and ruggedly constructed underwater -Jack Fisher, President metal detectors you can own��� Diver Mag 1 Pulse 8X Diver Held Mag $8,995 Underwater Metal Detector Only $2,150 Call for a free catalog or visit our web site: jwfishers.com CT-1 MC-1 Proton 4 Mini Camera $2,045 Cable Tracker with Signal Injector $14,495 ROVs Side Scans Marine Magnetometer $12,995 Fishers Pulse 6X and 8X detectors detect all metals, on land and underwater. Their Diver Mag 1 is a super sensitive detector for iron/steel targets and works equally well above and below water. All are built for commercial operations and have both audio and visual readouts. Interchangeable coils are available for the Pulse 6X and 8X. $19,995 Scan-650 $19,995 Scanning Sonar $6,995 1953 County St., E. Taunton, MA 02718 USA ��� (800)822-4744 (508)822-7330 ��� FAX: (508)880-8949 ��� email: jwfishers@aol.com ��� www.jwfishers.com 64 st / FEBRUARY 2013 www.sea-technology.com