写真測量とリモートセンシング
Online ISSN : 1883-9061
Print ISSN : 0285-5844
ISSN-L : 0285-5844
60 巻, 5 号
選択された号の論文の14件中1~14を表示しています
巻頭言
カメラアイ
災害小特集「東日本大震災以降の主な災害とその対応」
原著論文
  • 高橋 元気, 増田 宏
    2021 年 60 巻 5 号 p. 266-275
    発行日: 2021年
    公開日: 2022/11/01
    ジャーナル フリー

    For road mapping, it is important to add labels to point clouds captured by the Mobile Mapping System (MMS). Some automatic labeling methods have been proposed so far. However, in our experiment, conventional labeling methods were not sufficiently accurate for actual point clouds measured in Japan. In this paper, we propose a high-performance classification method that combines the multi-scale features of point clouds, the MMS specific features and the features obtained from point clouds mapped on the 2D image. The accuracy of the proposed method was evaluated using actual MMS data, and it was confirmed that the proposed method could achieve high recognition rate generalization performance. Our method can improve the accuracy of automatic labeling of point clouds, and is expected to improve the efficiency of map maintenance, which is a social infrastructure.

技術報告
  • 岡本 勝男, 竹村 文, 龍見 栄臣, 小林 浩
    2021 年 60 巻 5 号 p. 276-281
    発行日: 2021年
    公開日: 2022/11/01
    ジャーナル フリー

    Estimating damage to forests by strong winds is presented. In this study, a method to detect disaster-stricken forests by using the normalized difference vegetation index (NDVI) ratio before and after a disaster was developed. Chiba prefecture was selected as the test area. Many trees in Chiba prefecture were fallen due to strong winds of the Typhoon 15 (T1915) in 2019. One Sentinel-2 MSI dataset before T1915 and three after it were used for detecting wind fallen trees (WFTs). NDVI ratios in pure pixels of WFTs (WFT100%) were examined. NDVI ratios in pure pixels of no WFT (WFT0%) were also examined. Three linear interpolation expressions between WFT100% and WFT0% for MSI dataset after T1915 were developed to estimate the area ratio of WFTs in each mixel. 78% of WFTs detected by visible interpretation of aerial photographs were located in pixels with the area ratio of WFTs greater than 0%. In contrast, 93.4% of pixels with the area ratio of WFTs greater than 0% actually included WFTs. This method is useful to estimate the distribution of WFTs in the wide area.

研究速報
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