大连市09年初三二模英语答案

Uses entire station meter Shi Ceda the cross section the method mainly to have the coordinate and the opposite side survey law two kinds. Erects the control point the entire station meter the coordinate survey law, the merit is may unifies the topographic survey and the big cross section survey also carries on, but increased the quantity to take the instrumental height the error, the survey elevation's precision compared does not erect must be slightly low in the control point coordinate and the opposite side survey law. Does not measure takes the instrumental height the coordinate and the opposite side survey method measuring accuracy is the same, may meet four and so on leveling requirements at least. The recommendation uses entire station meter opposite side survey law Shi Ceda the cross section. The opposite side survey law is more advanced than the coordinate survey law, the measuring accuracy is higher, sets up a station the operation only to need to level off the instrume