教学目标掌握三角网外业观测方法和测站平差,了解精密导线测量和...（Teaching objective Master triangulation industry observation method and station adjustment, understand precise traverse survey and...）.doc

教学目标掌握三角网外业观测方法和测站平差,了解精密导线测量和...（Teaching objective Master triangulation industry observation method and station adjustment, understand precise traverse survey and...） Second lectures Teaching objective: to master the observation method and station adjustment of triangulation network, and to know the main points and methods of precise traverse survey and precise leveling. Focus and difficulty: direction observation method Two, triangulation angle observation For the purposes of engineering survey specifications, the requirements for each grade of triangulation accuracy and the number of measurements are shown in table 2-4. 1. observation methods and cautions Generally speaking, the direction observation method (i.e., circle measuring method) is adopted to measure the angle of triangulation. Table 2-5 data for the whole circle measurement method, horizontal angle observation records and calculation examples. In order to reduce the influence of the error of the dial and micrometer, the readings of the starting direction of each measurement should be evenly distributed on the dial and The readings of the starting directions of each measuring unit can be calculated according to the following formula Type M- measured back number; J - check back ordinal numbers (J, =1, 2, 3,..., m); I- horizontal dial minimum interval score, DJ1 type instrument is 4, DJ2 type instrument is 10; W- micrometer, number of compartments, type DJ1, instrument w=60, type DJ2, instrument w=600. According to the above formula, the position chart of the direction observation meter is compiled according to the above formula. Calculation and examination of 2. direction observation method In view of the horizontal angle, the requirements of the limits in table 2-6 shall be met. (1) check the direction and observe the value: (2) check the calculation of the semi test regression zero difference: if the zeroing is out of bounds, the semi test response re test. (3) calculate the 2C value: 2C the differenc