摘要
机载激光雷达(light detection and ranging,Li DAR)技术具有受天气干扰小、能穿透一定厚度植被获取地表信息和数据处理过程相对简单等优势。通过与定位定向系统(position orientation system,POS)集成,机载Li DAR点云数据可快速生成精细数字高程模型(digital elevation model,DEM)。DEM是滑坡调查与监测的一种基础图件,其精细程度可直接反映地表形态的微小变化。通过DEM可在三维环境下准确地对滑坡特征参数进行定量分析。利用Li DAR技术对湖北省秭归县张家湾滑坡进行了识别与参数提取的研究和应用。首先,利用航带平差法和不规则三角格网加密对获取的点云数据进行检校与滤波处理,制作出高精度DEM成果;然后,通过DEM生成的山体阴影图、坡度图和地表粗糙度图,实现了对滑坡体的定性与定量分析;最后,完成对分析结果的评估。结果表明,机载Li DAR生成的高精度DEM可以清晰地识别出滑坡,并能够准确地对各种滑坡要素进行定量提取和分析。
Combined with the positioning and orientation system(POS),the airborne Li DAR system acquires the three dimensional coordinate information of ground objects,and has the capability of fast generation of high-precision digital elevation model(DEM).DEM is a basic map for landslide investigation and monitoring.Its precision can reflect the small ground surface changes directly.The DEM can be used to quantitatively analyze landslide characteristics accurately.There are several advantages of airborne Li DAR technology:it is affected little by weather,it can penetrate the vegetation layer to obtain the ground surface information and its data-processing process is relatively simple.In this paper,the Li DAR technology was applied in Zhangjiawan Village,Zigui County,Hubei Province.The results show that,based on Li DAR technology,landslides can be recognized clearly with slide mountain shadow maps made with high precision DEM and,what is more,quantitative analysis can be carried out to measure landslides characteristics.
引文
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