基于伪距相位组合实时探测与修复GNSS三频非差观测数据周跳

Real-time Cycle-slip Detection and Repair Based on Code-phase Combinations for GNSS Triple-frequency Un-differenced Observations

三频观测量能形成具有更长波长、更小噪声、更小电离层影响等优良特性的组合观测量,有利于提高周跳探测和修复的精度。推导伪距相位组合探测周跳的阈值条件;提出周跳确定成功率的概念;并从提高周跳确定成功率出发,给出伪距相位组合选取的标准和方法;最后利用一组实测GPS三频数据进行验证。结果表明,在数据采样率较高、历元间电离层延迟变化可忽略时,根据该方法选取的最优伪距相位组合可实时探测和修复三频非差观测数据中的所有周跳。

In case of triple-frequency signals, there are many combination observations with longer wavelength, smaller noise, smaller ionosphere effect, which may improve the precision of cycle-slip detection and repair. The threshold for cycle-slip detection is deduced, and the success rate of cycle-slip determination is proposed. Criterions and methods for selecting code-phase combination are presented in order to enhance the success rate of cycle-slip determination. At last, experiments are carried out to test the performance of the method using GPS triple-frequency observations. The result shows that optimal code-phase combinations selected by proposed criterions can detect and repair all cycle-slips of triple-frequency un-differenced observations, when ionosphere error between-epoch can be ignored in case of high data rate.