When I put a test branch in the tube, I aligned the zero degree mark on one compass to match up with the first offshoot branch.
我把被测试的树枝放入这个试管，将一支量角器的零刻度线对准第一个侧枝。
2
The method of difference, geometry-free combination, melbourne-wubbena combination for cycle slip detecting are analyzed in this paper. Then the test of cycle slip using COMPASS observations is made.