Abstract High-rate GNSS observations are essential for applications requiring precise positioning over short intervals. These observations are sampled at 1–100 Hz, and are widely used in seismic monitoring, early warning systems, and structural health monitoring. The increasing availability of low-cost GNSS instruments has made high-rate GNSS more accessible while enhancing its potential for precise positioning. However, unlike high-end geodetic instruments, which undergo extensive calibration and refinement, low-cost GNSS instruments exhibit diverse noise characteristics that must be systematically analysed and quantified. To deploy low-cost GNSS instruments for earth monitoring requires a clear understanding of the stochastic behaviour of the observations. This study investigates the stochastic behaviour of low-cost GNSS observations through controlled standalone, short-baseline (SB1, SB2), and zero-baseline (ZB) experiments. We tested multiple low-cost receivers (u-blox Neo-M8T single-frequency and u-blox ZED-F9P dual-frequency) and antennas (u-blox ANN-MB-00 patch, Tallysman TW3972 dual patch, dual-band multi-feed survey-grade, and Tallysman VeraPhase VP6000 full-spectrum), in comparison to a survey carried out using a Trimble R10 receiver. The results indicate that the type of code noise in a low-cost dual patch antenna paired with a u-blox ZED-F9P differs significantly from that observed in the survey-grade Trimble R10 at 1 and 2 Hz. The precision of the dual-band multi-feed and Tallysman full GNSS spectrum antenna is nearly identical, while the low-cost dual patch paired with the u-blox ZED-F9P and high-end Trimble R10 exhibits comparable performance. The results further show that Galileo E5 (E5 and E5b) code observations exhibit the lowest thermal noise among all signals. The low-cost dual-patch antenna paired with the single-frequency u-blox NEO-M8T receiver maintains acceptable precision and demonstrates stable carrier-phase tracking up to 5 Hz. However, the pseudorange code measurements remain strongly constrained by the receiver design and antenna quality.