A review of advanced low-cost GNSS technologies for navigation and precipitable water vapour monitoring

Low-cost Global Navigation Satellite System (GNSS) receivers and antennas have emerged as promising alternatives to geodetic-grade equipment for precise positioning and atmospheric monitoring applications. Integrating multiple GNSS constellations, advanced positioning techniques such as Precise Point Positioning (PPP) and Real-Time Kinematic (RTK), and improved antenna designs have significantly enhanced consumer-grade GNSS hardware capabilities for Position, Navigation, and Timing services. This paper surveys PWV estimation using low-cost GNSS receivers, including smartphones (Huawei P40, Huawei Mate 20X), consumer chipsets (u-blox ZED-F9P, u-blox M8T, Piksi Multi, Unicorecomm Nebulas II), and low-cost antennas. Multi-constellation configurations (GPS, GLONASS, Galileo, BeiDou, QZSS) consistently improved accuracy and reduced convergence times. PPP achieved sub-meter to centimeter-level accuracy; RTK demonstrated 2–5 cm horizontal accuracy. Tropospheric ZTD estimates agreed with geodetic equipment to 3–8 mm RMS, and PWV retrievals agreed with radiosonde and reanalysis products to within 1–3 mm. Low-cost GNSS has matured to near-geodetic performance for many applications. Antenna quality remains the primary accuracy differentiator multipath mitigation, ambiguity resolution for noisy receivers, this is a challenging task for improving positional accuracy for GNSS RTK users.