Assessing the Metric Reliability of NRTK-Based Surveying Systems for Multi-Scale Architectural Documentation: Experimental Tests and Real-World Applications

Network Real-Time Kinematic (NRTK) correction services have lowered the barrier to georeferenced surveying by enabling centimetric GNSS positioning without deploying a local base station, but their “end-to-end” metric reliability in multi-sensor architectural workflows remains strongly dependent on platform-specific error source (Rizos 2002). This paper assesses the geometric consistency achievable when NRTK is used as the sole georeferencing backbone for multi-scale heritage documentation, combining a controlled benchmark with a real-world application on the survey of Villa Farsetti and its park in Santa Maria di Sala, Italy. The benchmark compares four NRTK-enabled platforms (geodetic GNSS, handheld SLAM system, UAV, and DSLR with RTK Hotshoe tagging) against a topographic reference. The field campaign replicates the same NRTK toolchain on the villa’s architectural envelope and landscape, while defining an independent reference via a static GNSS-supported control network and static terrestrial laser scanning (TLS). Quality assessment is designed around point-based check residuals, baseline/scale diagnostics, and dense cloud-to-cloud and M3C2 comparisons to TLS reference clouds (Besl et al. 1992). The study provides a practical, reproducible validation framework to decide when NRTK-only architectures can support 1:50–1:100 deliverables and when supplementary control is still required.