Consumer GNSS chipsets-based, dual-frequency receivers as enablers of precise navigation and dense networks

A new low-cost L1/L2c receiver board is presented in this short letter, along with its first tests. The main strength of the board is its low price tag (around 200 EUR, in quantities of hundreds) as an effective dual-frequency receiver. The effectiveness of the receiver was at first proven by a pedestrian walk experiment on a closed loop, allowing the evaluation of closure errors. Raw measurements were collected and processed in a real-time scenario through a variometric approach implemented in VADASE software. Epoch-by-epoch velocities were estimated on the basis of dual-frequency phase observations and then the trajectory was reconstructed by numerical integration of the estimated velocities. A horizontal closure error lower than 25 cm was achieved; also, a global assessment of the overall 3D trajectory was carried out, performing a comparison to a standard differential solution with respect to a permanent GNSS station, and standard deviations of the differences between 10 and 20 cm for the 3D components (east, north and up) were achieved. Further, static experiments, both in terms of relative positioning and water vapor monitoring by precise point positioning, confirmed the good performance of the new receiver, with coordinates repeatability of a few millimetres for daily solutions, and estimated water vapor behaviour compatible with local rain events.