BeiDou system satellite‐induced pseudorange multipath bias mitigation based on different orbital characteristic for static applications

An improved triple‐frequency cycle slip detection and repair method based on wavelet packet transform and adaptive threshold for BeiDou System satellite

“…On the basis of the above, the satellite‐induced code bias can be extracted by the code bias combination model, which is expressed as follows [32]: $$$\left\{\begin{array}{l}{M}_{b1}={P}_{\mathrm{b}1}+\frac{1+\alpha }{1-\alpha }{\varphi }_{b1}+\frac{2}{\alpha -1}{\varphi }_{b2}+{B}_{b1}\\ {B}_{b1}=\frac{\alpha +1}{\alpha -1}\left({m}_{b1}+{n}_{b1}{\lambda }_{b1}\right)+\frac{2}{1-\alpha }\left({m}_{b2}+{n}_{b2}{\lambda }_{b2}\right)\end{array}\right.$$$ where P and ϕ denote the original code and carrier phase observations, respectively; The α is the f 2 b1/ f 2 b2; f b1 and f b2 denote the frequencies of B1 and B2 bands of BDS satellite, which are 1561 and 1207 MHz, respectively; m is the multipath error of carrier phase observation and the maximum is a quarter of the wavelength. For example, the maximum carrier phase multipath of B1 frequency is only approximately 0.0475 m. However, the satellite‐induced code bias mainly fluctuates on the level of metres [33]. Thus, the carrier phase multipath is far less than the satellite‐induced code bias, and it can be ignored in Equation (13).…”

“…where P and φ denote the original code and carrier phase observations, respectively; The α is the f 2 b1/f 2 b2; f b1 and f b2 denote the frequencies of B1 and B2 bands of BDS satellite, which are 1561 and 1207 MHz, respectively; m is the multipath error of carrier phase observation and the maximum is a quarter of the wavelength. For example, the maximum carrier phase multipath of B1 frequency is only approximately 0.0475 m. However, the satellite-induced code bias mainly fluctuates on the level of metres [33]. Thus, the carrier phase multipath is far less than the satellite-induced code bias, and it can be ignored in Equation (13).…”

“…where E is the elevation of current epoch; b k is the coefficient of polynomial fitting. Further information can be found in Zou et al [34] and Su et al [33].…”

“…The last column means the repair results of the proposed method. N means the method cannot detect the - 33 cycle slip. Y denotes the method can detect the cycle slip effectively.…”

UWB Positioning Algorithm Based on Fuzzy Inference and Adaptive Anti-NLOS Kalman Filtering

“…Under the influences of such factors as the blockage of buildings and the complexity of environments, the traditional outdoor global positioning system (GPS) satellite positioning technology is becoming unable to meet the requirements of indoor and outdoor positioning due to great positioning errors [1]. Compared with Wi-Fi, radio frequency identification, ultrasound, Bluetooth and other positioning technologies, ultra-wideband (UWB)-based positioning technology has many advantages, including centimeter-level positioning accuracy, good multi-path resistance, preferable resistance against the interference of other electronic signals from complex environments and strong penetrability [2,3], which not only endow it with high reliability but also facilitate the collection of dynamic data and real-time positioning of moving objects in complex environments [4]. The emergence of the fifth-generation mobile communication technology (5G) provides a new idea for highprecision indoor positioning.…”