Development of the GPS observation system using the low-cost dual-frequency GPS receiver and data logger

We developed a GPS observation system using the combination of a low-cost GNSS receiver and a LINUX data logger for the crustal deformation monitoring. We implemented three functions on the system. The first one is the data logging of GNSS streaming data, the second one is controlling the GNSS receiver, and the last one is conversion to RTCM format that is streamed by means of TCP/IP for RTK-GPS processing. We assessed the GPS data quality by two kinds of tests. At first, we checked the zero-baseline kinematic post-processing using 20Hz sampling data obtained by an expensive geodetic-level receiver and our newly developed system. The standard deviations of the resulting time series are 0.85 mm (EW), 1.17 mm (NS), and 1.62 mm (UD), respectively. Next, we tested the long-baseline (178.5 km) real-time kinematic analysis. We conclude that our new GPS observation system has functions and capabilities comparative to expensive geodetic-level receivers used for the crustal deformation monitoring with inexpensive costs.