Buildings as a barrier to sound

Block model (LOD1) for noise mapping 2022 LOD1 building heights are determined automatically by calculating an average of the heights of the laser scanner data within the floor plans. Photogrammetric measurement uses the mean value between first and eave height. If necessary, floor plans are divided if this average deviates too much from the building parts due to different heights of the building parts (> 2 m, > 20 sqm) and then calculates new mean values of the building parts. Thus, an exact picture of the roof landscape is achieved in the LOD1 block model, depending on the roof shape, the absolute height accuracy is < 3 m.2022年噪声制图专用块模型（细节层次1，Level of Detail 1，LOD1） LOD1建筑高度通过计算建筑平面图范围内激光扫描仪数据的平均高度自动确定。摄影测量则取首拍高度与檐口高度的平均值。 若因建筑部件自身高度差超过2米且面积大于20平方米，导致计算所得平均值与建筑部件偏差过大，则需拆分建筑平面图，并重新计算各建筑部件的平均高度。 借此，LOD1块模型可精准呈现屋顶全貌；依据屋顶形态的差异，其绝对高度精度可达<3米。