[1] Real-time crustal deformation monitoring is extremely important for achieving rapid understanding of actual earthquake scales, because the measured permanent displacement directly gives the true earthquake size (seismic moment, M w ) information, which in turn, provides tsunami forecasting. We have developed an algorithm to detect/ estimate static ground displacements due to earthquake faulting from real-time kinematic GPS (RTK-GPS) time series. The new algorithm identifies permanent displacements by monitoring the difference of a short-term average (STA) to a long-term average (LTA) of the GPS time series. We assessed the noise property and precision of the RTK-GPS time series with various baseline length conditions and orbits and discerned that the real-time ephemerides based on the International GNSS Service (IGS) are sufficient for crustal deformation monitoring with long baselines up to $1,000 km. We applied the algorithm to data obtained in the 2011 off the Pacific coast of Tohoku earthquake (M w 9.0) to test the possibility of coseismic displacement detections, and further, we inverted the obtained displacement fields for a fault model; the inversion estimated a fault model with M w 8.7, which is close to the actual M w of 9.0, within five minutes from the origin time. Once the fault model is estimated, tsunami waveforms can be immediately synthesized using pre-computed tsunami Green's functions. The calculated waveforms showed good agreement with the actual tsunami observations both in arrival times and wave heights, suggesting that the RTK-GPS data by our algorithm can provide reliable rapid tsunami forecasting that can complement existing tsunami forecasting systems based on seismic observations. Citation: Ohta, Y., et al. (2012), Quasi real-time fault model estimation for near-field tsunami forecasting based on RTK-GPS analysis: Application to the 2011 Tohoku-Oki earthquake (M w 9.0),

Precise satellite orbits and clock information for global navigation satellite systems (GNSS) allow zerodifference position solutions, also known as precise point positioning (PPP) to be calculated. In recent years numerical weather models (NWM) have undergone an improvement of spatial and temporal resolution. This makes them not only useful for the computation of mapping functions but also allows slant troposphere delays from ray-tracing to be obtained. For this study, such ray-traced troposphere corrections have been applied to code and phase observations of 13 sites from the International GNSS Service (IGS) receiver network, which are located inside the boundaries of the Japanese Meteorological Agency (JMA) meso-scale weather model, covering a period of 4 months. The results from this approach are presented together with a comparison to standard PPP processing results. Moreover the advantages and caveats of the introduction of ray-traced slant delays for precise point positioning are discussed.

The purpose ofthis paper is to improve GLONASS positioning perfbrmance in RTK − GPSIGLONASS between different types of receivers ． Tables。f inter − channel code biases in various receivers were obtained with a zero baseline test in order to examine the magnitude of inter − channel code bias between the receivers ． We showed the improvement of fix rate and positioning accuracy of RTK − GPSIGLONASS between diffbrent types of receivers by using table ofthe calibrated GLONASS biases and partial ambigUity fixing solution ofGPS and GLONASS for the aid of GPS carrier − phase ambiguity resolution ． Furthermore ， we showed that the bias correction method suggested in this paper is applicable te RTK − GPSIGLONASS with multi − epoch measurements as well as with sing ］ e − epoch measurements ． Keywortty：R η く GLOIVA ∬ ， ハ D翩 ， Inter − channel harcbvare bias

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In order to apply satellite positioning to train control, an algorithm for positioning was developed with a one-dimensional constraint condition using line coordinate data and multipath error reduction using the given value, different physical phenomena, and satellite redundancy. The positioning performance was evaluated using the positioning satellite observational data acquired on operating lines, confirming that large errors were reduced and that there fewer drops in the positioning rate quality. The algorithm was then transferred to the embedded system and confirmation was obtained that 10 Hz real-time positioning could be performed.