Integrity monitoring for undifferenced and uncombined PPP under local environmental conditions

Integrity monitoring of precise point positioning (PPP) can provide tightly guaranteed absolute position error bounds for safety-critical applications. However, a complex local environment makes PPP integrity monitoring much more challenging, such as urban canyons. Significant prone multipaths and low observation redundancy are the main difficulties in the accuracy and reliability of PPP. Therefore, we proposed a solution separation-based integrity monitoring algorithm, which is based on a single and dual frequency undifferenced and uncombined PPP model considering compensation for the multipath error distortion by Gaussian overbounding. Both the static and the kinematic data are utilized to test the proposed algorithm. The results show that the proposed algorithm can produce an adequate protection level (PL) in horizontal and vertical directions. Furthermore, the proposed algorithm can obtain a smoother PL and positioning error in a dynamic local environment, and effectively suppress misleading information.