By the criterion 1, the range of searching velocity has been confined to , where denotes the searching velocity which matches the target’s radial velocity , i.e., . Thereafter, the criterion 2 is introduced to select among . On one hand, the RM can be completely corrected when the searching velocity is , then optimal integration can be obtained. On the other hand, due to the long-time integration, can be easily satisfied, which indicates that the RM cannot be completely removed when the searching velocities are , and will result in integration loss. Therefore, criterion 2 implies that the final matched velocity can be selected from the set of .