Public Land Survey Monument

A featureclass depicting survey monuments. A monument is a permanent marker placed at the location of a corner. Today, permanent monuments can be an aluminum pipe and cap or an iron rod and plastic cap. In the past, original PLSS surveys often utilized wooden stakes or posts, marked trees, or stones, mounds of rocks, pits, or other less-permanent monuments to mark corners.本要素类（featureclass）用于描述测量标志物。测量标志物指设置于拐点位置的永久性标识物。当前，永久性标志物可采用铝管配管帽，或是铁棒配塑料帽的形式。早期公共土地测量系统（Public Land Survey System，简称PLSS）的野外测量作业中，常采用木桩、带标记的树木、石块、石堆、坑穴或其他耐久性较弱的标志物来标注拐点。