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都市の景観を管理する上では景観の統一性・連続性が重要であるが，これらを分析するには広範囲における景観の把握が必要である．航空機LiDAR(Light Detection and Ranging)は，広範囲の3次元の座標を高速に取得することができる．本研究では航空機LiDARで計測したDSM(Digital SurfaceModel)，DTM(Digital Terrain Model)のデータを用いて，広範囲における任意の地点での囲繞度を推定する手法を提案する．囲繞度は，視野の立体角に対する地物の立体角の占める割合として定義した．京都市東山区を対象に提案手法を適用した結果，やや過小評価気味ではあったが，囲繞度を誤差約3％で推定することができた．, This paper proposes a methodology to estimate an "enclosure index" in urban areas using airborne LiDAR. The index is defined as a ratio of occluded area to whole of area in azimuth angle-elevation angle space. The index can be applied to assess local landscape, and it is expected to estimate it in a wide area at low cost. The author examined the methodology to estimate it using airborne LiDAR data measured in last-pulse mode. The estimated index map was validated with the ground truth data, and the error was acceptable, approximately 3%. Even though the last-pulse mode data may underestimate actual digital surface model (DSM), it was found that the proposed methodology is effective to estimate the index in a wide area at low cost.

This paper discusses the generation of a high precision DEM (Digital Elevation Model) based on high density airborne LiDAR (Light Detection and Ranging) data for an interdisciplinary landscape archaeological study concerning the settlement history and environment in Sandy Flanders, a region to the north of Ghent (Belgium). The objective was to create a detailed topographical surface free of artificial features and topographical artefacts, in the form of a DEM, visualizing the natural and current topography through the implementation of true ground points only. The semi-automatical removal of these features and artefacts was based on topographical vector data, visual interpretations and slope analysis. Ultimately two DEM's were constructed (1) a TIN (Triangulated Irregular Network) model, whereby the inherent large file format restricts the usability to large scale and (2) a grid model which can be used for small-, medium- and large-scale applications. Both datasets were used as an image that is interpreted using ancillary data from historical sources. Its usefulness is illustrated in a case of field pattern and microfield topography. Starting from this DEM, the approach of this landscape historical study is mainly retrogressive, i.e. starting from the landscape structures and elements that are still present in the contemporary landscape and moving into the past.