A Comparison Between Hard- and Soft-Constrained RTK Positioning With Multiple Reference Antennas

摘要: Real-time kinematic (RTK) ambiguity resolution can be improved by engaging multiple reference antennas. The baseline information between the antennas taken as true values and used a hard-constraint; or it regarded weighted, priori measurements, soft-constraint. In this contribution, comparison two constraints is made to explicate their difference in RTK for some specific applications, which coordinates of cannot accurately calibrated advance. functional stochastic models hard soft-constrained positioning are given. float precision unconstrained, cases compared. closed-formulae dilution (ADOP) unconstrained hard-constrained derived, they proven upper lower bound ADOP, respectively. A simulated real data show that, with soft-constraints, single-frequency success rate, well performance time-to-first-fix (TTFF), significantly. When there bias smaller than 6 cm vectors antennas, have comparable rate. Also, sharp increase TTFF observed at same time. gets larger, rates decreased drastically. contrast, soft-constraint maintains relatively good performance, showing much greater tolerance bias.