Development of aerial photographing system with throwing device for disaster information gathering
Recently, as a disaster information gathering tool, aerial photographing devices which gather photos and videos from the air get much attention. Especially, the aerial photographing method at low altitude below 15 meters is important to the disaster information gathering. As these devices, there are helium gas balloons, radio-controlled helicopters, and pole/crane vehicles. However, these devices have risks that trigger accidental contact and crackup by air stream at low airspace. In order to improve the safety of these devices, in this paper, we have developed a throw type photographing system which consists of an automatically photographing device packaged in a plastic capsule egg and a launching device. The attitude of the photographing device is controlled by the microcomputer with acceleration, gyro and compass sensors. These sensors also used to estimate the time when the device reaches the top of air. Moreover, we have shown the effectiveness of the proposed system by shooting aerial photographs in practice.
A DCM Based Orientation Estimation Algorithm with an Inertial Measurement Unit and a Magnetic Compass
In this paper, Direction Cosine Matrix (DCM) method for attitude and orientation estimation is discussed. DCM method was chosen due to some advantages over the popular methods such as namely Euler Angle, Quaternion in light of reliability, accuracy and computational efforts. Proposed model for each method is developed for methodology comparison. It is shown that normal Kalman Filter in DCM method is better than extended Kalman Filter in Euler and Quaternion based method because it helps avoid the first order approximation error. Methodology errors are verified using Aerospace Blockset of Matlab Simulink.
Field survey of the coastal impact of the March 11, 2011 great East Japan tsunami
A fi eld survey has been performed in the tsunami hit areas of Great East Japan Tsunami. We report our fi ndings from Sendai Airport, Yuriage, Natori, Sendai port, Taro, Miyako, Yamada, Kamaishi, Rikuzentakata, Ofunato and Kesennuma. We also present simulaƟ ons of tsunami inundaƟ on and compute nearshore tsunami parameters and diff erent characterisƟ cs of the incoming tsunami. We present an assessment of the performance of coastal structures (tsunami walls, breakwaters, port structures, quays and defense structures), countermeasures, building damage, possible reasons of building damage. Furthermore, the tsunami impact, building response and tsunami miƟ gaƟ on strategies are discussed.