IGS Tide Gauge Benchmark Monitoring Pilot Project (TIGA): scientific benefits

The establishment of a long-term stable global reference frame is important for studying sea level records for, e.g., climate-related studies. GPS stations connected to the tide gauge benchmarks provide the necessary technique. However, the analysis of existing GPS solutions showed inconsistencies within the time series especially for the height component. To solve related issues, in 2001 the IGS Tide Gauge Benchmark Monitoring Pilot Project was established. The aim is the processing and re-processing of GPS data of stations at or near tide gauges in order to provide homogeneous and high-quality estimates of the vertical motion. A second objective is the establishment, maintenance and expansion of existing network of GPS stations at tide gauges. During the recent years six different analysis centers have processed overlapping GPS at tide gauge networks and are providing individual solutions allowing now to provide a combined solution. The ansatz for the combination is explained and quality measures are given. In addition, on the basis of the reconstruction of sea level anomalies, the benefit of using the combined TIGA solution is demonstrated.