随着国家四化建设的发展,大比例尺测图越来越多,精度要求也较高,而目前普遍使用经纬仪配合小平板测绘,以量角器按极座标法展点绘图,在图的每一个测站上,用有机玻璃量角器一点一点地多次进行展绘,每展一点都要重新对方位线,往往会出现一定误差,也占时间。据此,笔者在实践中改进成一种透明胶片量角器(以下简称胶片量角器)代替有机玻璃量角器。 With the development of the four modernizations in the country, more and more large-scale mapping and higher accuracy are required. At present, theodolite and microlithography are generally used to map protracts according to the polar coordinate method. In each of the figures Stations, with protractor protractor little by little to develop the exhibition, each show a bit to be re-alignment bit line, there will always be a certain error, but also time. Accordingly, I improved in practice into a transparent film protractor (hereinafter referred to as film protractor) instead of plexiglass protractor.