VALIDATION OF THE OPTIMAL PAN TIME TO RENDER PANORAMIC IMAGES USING THE FUNCTION OF DEVICES EQUIPPED WITH CCTV CAMERA

 Many natural disasters such as earthquakes and floods occur in Japan. In the case of earthquakes outside working hours, at night or on holidays for example, officials of disaster management bureaus of government agencies need time to return to their offices. It is, therefore, necessary to construct an automatic system which rapidly shares disaster information among such officials.<br> The Ministry of Land, Infrastructure, Transport and Tourism (MLIT) has developed and been utilizing CCTV (Closed Circuit Television) cameras to survey infrastructure on roads and rivers and to support disaster management. Officials of disaster management bureaus of the MLIT attempt to check as many CCTV cameras as possible to clarify damage to infrastructure. Under such circumstances, they have no time to rotate the CCTV cameras to obtain a broad panoramic view of their surroundings. To support early-stage governmental decision-making after an earthquake, the National Institute for Land and Infrastructure Management (NILIM) has been studying the construction of a system that will automatically select the CCTV cameras in areas where the measured seismic intensity exceeded a preset level based on municipal unit seismic intensities and rotate the corresponding CCTV cameras to render panoramic images of their surroundings.<br> To introduce the system, we have to clarify the time officials of MLIT disaster management bureaus need to check panoramic images. CCTV cameras satisfy a common specification set by the MLIT to maintain their quality throughout Japan. Therefore, we must also clarify the method of rotating each kind of CCTV camera to completely pan its surroundings.<br> We confirmed the behavior of the system and performed trials to measure the time it takes for 10 CCTV cameras along Tsurumi-River to completely pan 180 degrees. Under this condition, we clarified that rendering panoramic images is failing when we spend no more than 8 seconds.