在利用W-M宽巷组合进行周跳初步探测的基础上,加入了新方法进行二次周跳探测。该方法通过利用来自同颗GPS卫星的无电离层影响L3组合相位观测值在相邻历元间的变化量与dm级精度的先验轨道坐标,计算得出星载GPS接收机历元间的钟差变化值。对于存在周跳的载波相位观测值,其计算结果会与同历元其他无周跳观测值解算的钟差变化量存在较大差异。实验结果表明,二次探测可以发现新的周跳并对初步探测结果进行检核。
On the basis of preliminary cycle slip detection by the W-M wide lane linear combi- nation, a new method is introduced to make a second detection. The differences of the iono- sphere-free L3 combination observables in the successive epochs can be used to work out the change of receiver clock errors when a-priori satellite orbit is known. For observables with cycle slips,their resulting values would be distinct from others in the same epochs. Expri- mental results show that new cycle slips can be dug out while detected cycle slips in previous step are verified by the twice detection method.