Abstract Low-cost GNSS networks are transforming geospatial monitoring by providing dense, real-time, and affordable positioning infrastructure. They have the potential to reveal new geophysical insights that were hitherto prohibitive due to GNSS infrastructure costs. Given this rapid rise and the immense potential of low-cost networks, it is imperative to assess their quality. In this study, a framework is put together to find out the quality of a new low-cost GNSS network, and thereafter, to monitor it continuously. Metrics are identified with the aid of the International GNSS Service (IGS) guidelines to check the quality of four different aspects of a station in the network: (i) station (satellite visibility, DOP, multipath), (ii) signal reception (carrier-to-noise ratio, cycle slips), (iii) network (double-difference residuals, post-fit normalized root mean square (NRMS), and (iv) atmospheric sensing (Zenith Tropospheric Delay). We demonstrate this framework by characterizing the heterogeneous and continuously operating low-cost GNSS network in India, LCG-IITK. The stations show comparable performance to nearby IGS stations in terms of DOP and positioning accuracy, while multipath exhibits similar trends with site-dependent variations. Phase observations show comparable performance, reflected in acceptable one-way double-difference RMS values and NRMS values approaching 0.2 across configurations. ZTD estimates exhibit minimal error, with high correlation ( R = 0.98) and low RMS of difference (8.84 mm) relative to IGS station, highlighting the suitability of low-cost GNSS stations for atmospheric sensing. The proposed framework is provided as an open-source Python package, c-GNSS, which provides automated daily and weekly health reports for continuous GNSS network monitoring.
Anwar et al. (Sun,) studied this question.