Massive terminal positioning system with snapshot positioning technique

Traditional navigation and location techniques currently demonstrate difficulties, such as high costs and high-power consumption, which are challenged by new requirements of massive terminal positioning applications, such as wildlife monitoring, digital pasturing, and positioning of shared bikes. These applications demand a long-term but intermittent positioning solution that has a low cost and low-power consumption. A new solution is proposed to process GNSS data based on an improved snapshot positioning algorithm at a reference station instead of a local chip. In the proposed system, each terminal only needs to take a snapshot of the GNSS signals for a few milliseconds and transmit it, along with the identity data, to the reference station through an LoRa module, which is a long-range and low-power wireless communication platform. The reference station obtains coarse measurements from assisted high-sensitivity acquisition and refines the measurements via generalized extended approximation and differential corrections. The coarse-time navigation solution is used to obtain the precise terminal position. Experiments were conducted to verify the proposed system under different conditions. A positioning accuracy of 3 m with the simulated signals and 6 m with the actual signals can be achieved with 20 ms snapshots at a 6.2 MHz sampling frequency. This research provides a new low-cost and low-complexity approach for massive terminal positioning.