DEVELOPMENT OF NEW AIRBORNE LASER SCANNING METHOD BY MEANDERING FLIGHT

Abstract. Japan has many meandering rivers in her mountainous areas. Many hazards have occurred in their surroundings. Airborne laser scanning (ALS) is one of measures for disaster prevention in the surrounding of a meandering river. In Japan, ordinary ALS by using both a fixed wing airplane and a rotary wing airplane adopts flying along straight lines over a target area. Although ALS along straight lines is effective when a target area is planar, ALS along straight lines for a meandering river in a mountainous area increases the number of flying courses and flight time. On the other hand, although ALS by a meandering flight along a target meandering river would be efficient in data acquisition, it depends on the skill of a pilot and brings difficulty in data processing to secure measuring accuracy. We decided to develop a new efficient ALS method by a meandering flight. It systematizes flight planning, GCP allocation, and data processing especially course adjustment to secure required measuring accuracy. After conducting preliminary experiments in the test area, measuring accuracy was verified following the operation guidelines for the Japanese public surveying established by the Ministry of Land, Infrastructure, Transport and Tourism of Japan. The result that the accuracy by a meandering flight would be almost the same as that by a straight-line flight, and indicated that it would meet the operation guidelines for Japanese public surveying.