<p>Monitoring the seafloor plate motion and relevant dynamic processes is a critical objective of seafloor geodesy. To resist the sound speed variation effects on the global navigation satellite system—acoustic (GNSS-A) technique, a seafloor array composed of a set of transponders was proposed and treated as a rigid body to reflect the tectonic displacement. In this contribution, we propose a rigorous rigid-array solution that combines long-term seafloor geodetic observations at the original observation level and then extend it to resilient-array solutions accounting for the deformation or distortion caused by tectonic motions. To conquer the computational and storage costs in the original observation level combination, a two-step algorithm for solving the resilient-array solution is proposed, and a Resilient GNSS-A Ranging Network Solver (GARNETS V1.0) program is developed, providing an efficient and flexible tool for analyzing the array displacement, deformation, and distortion. The proposed solutions and algorithm were validated using open-access Japanese GNSS-A data. It shows that the proposed rigorous rigid-array solution achieves three-dimensional positioning precision ~ 3 cm, achieving a precision improvement of ~ 2 cm (about 40% enhancement) for N–E coordinates and ~ 4 cm (over 50% enhancement) for U coordinate relative to the free-array solution. The proposed two-step algorithm assigning a sufficiently large resilient factor can produce a perfectly consistent result with the rigorous rigid-array solution but shows a great advantage in efficiency, e.g., when combining GNSS-A observations over 25 campaigns, it has a 39% reduction in computational and storage costs. In addition, the proposed rigorous rigid-array solution can avoid a positional discrepancy of the array up to ~ 1 cm compared to the traditional two-step rigid-array solution.</p>