Real-Time Kinematic Positioning for Unmanned Air Vehicles

In this paper, we describe an RTK method which estimates a code multipath parameter for each double difference to fully exploit the temporal correlation of multipath and to prevent a mapping of the multipath into the baseline and ambiguities. The ambiguity fixing is performed in two phases: In the first phase, sets of integer candidate vectors are derived fromthe float solution at multiple epochs. We merge the sets of candidate vectors to increase the likelihood of including the correct candidate vector in the set of candidates. In the second phase, we track each candidate vector by determining a single epoch baseline estimate for each candidate vector. The respective measurement residuals are accumulated over time to increase the likelihood of selecting the correct candidate. The proposed method was applied to real measurements from two low-cost ANavS GPS modules and enabled a millimeter-level positioning accuracy despite code multipath of up to 50 m.     «

In this paper, we describe an RTK method which estimates a code multipath parameter for each double difference to fully exploit the temporal correlation of multipath and to prevent a mapping of the multipath into the baseline and ambiguities. The ambiguity fixing is performed in two phases: In the first phase, sets of integer candidate vectors are derived fromthe float solution at multiple epochs. We merge the sets of candidate vectors to increase the likelihood of including the correct can...     »