MSPos: A Geomagnetic Matching Suitability-Incorporated Positioning Method in Indoor Environments

Numerous advanced geomagnetic positioning methods have made remarkable progress in indoor positioning. Nevertheless, the crucial factor of geomagnetic suitability, which significantly impacts positioning accuracy, has not been adequately considered. To address this problem, we propose a novel method named matching suitability-incorporated positioning (MSPos), which consists of two stages. In the geomagnetic matching suitability computational stage, we propose a connected features-based geomagnetic matching suitability computational method. We first extract geomagnetic connected features, then computing the evaluation values for each subregion based on the extracted features, and converting these values into the matching suitability. In the positioning stage, we propose a geomagnetic matching suitability-incorporated resilient positioning strategy. When the matching suitability of the subregion is strong, we propose a local spatial constraints-based positioning method to suppress the geomagnetic gross error at rare points. Conversely, if the subregion has weak matching suitability, we propose a pedestrian dead reckoning (PDR) heading assistance-based fusion method to reduce the error caused by geomagnetic mismatching. The resilient positioning strategy dynamically selects different methods incorporating the matching suitability of the subregion, where the pedestrian is situated. The performance of the method was evaluated in a real indoor environment. The experimental results show that the proposed MSPos method can achieve accurate and continuous positioning.