Tsukuba VLBI Analysis Center

The Tsukuba Analysis Center is funded by the Geospatial Information Authority of Japan (GSI). The c5++ analysis software is regularly used for the IVS-INT2 analysis and the ultra-rapid EOP experiments

Tsukuba VLBI Correlator

The K5/VSSP software correlator (Figure 1), located in Tsukuba, Japan, is operated by the Geospatial Information Authority of Japan (GSI). It is fully dedicated to processing the geodetic VLBI sessions of the International VLBI Service for Geodesy and Astrometry. All of the weekend IVS Intensives (INT2) and the Japanese domestic VLBI observations organized by GSI were processed at the Tsukuba VLBI Correlator

Ultra-rapid earth rotation determination with VLBI during CONT11 and CONT14

We present earth rotation results from the ultra-rapid operations during the continuous VLBI campaigns CONT11 and CONT14. The baseline Onsala--Tsukuba, i.e., using two out of the 13 and 17 stations contributing to CONT11 and CONT14, respectively, was used to derive UT1-UTC in ultra-rapid mode during the ongoing campaigns. The latency between a new observation and a new UT1-UTC result was less than 10 min for more than 95{\%} of the observations. The accuracy of the derived ultra-rapid UT1-UTC results is approximately a factor of three worse than results from optimized one-baseline sessions and/or complete analysis of large VLBI networks. This is, however, due to that the one-baseline picked from the CONT campaigns is not optimized for earth rotation determination. Our results prove that the 24/7 operation mode planned for VGOS, the next-generation VLBI system, is possible already today. However, further improvements in data connectivity of stations and correlators as well in the automated analysis are necessary to realize the ambitious VGOS plans

Tsukuba 32-m VLBI Station

The Tsukuba 32-m VLBI station is operated by the Geospatial Information Authority of Japan. This report summarizes activities of the Tsukuba 32-m VLBI station in 2012. More than 200 sessions were observed with the Tsukuba 32-m and other GSI antennas in accordance with the IVS Master Schedule of 2012. We have started installing the observing facilities that will be fully compliant with VLBI2010 for the first time in Japan

Current Status of the Development of a Transportable and Compact VLBI System by NICT and GSI

MARBLE (Multiple Antenna Radio-interferometer for Baseline Length Evaluation) is under development by NICT and GSI. The main part of MARBLE is a transportable VLBI system with a compact antenna. The aim of this system is to provide precise baseline length over about 10 km for calibrating baselines. The calibration baselines are used to check and validate surveying instruments such as GPS receiver and EDM (Electro-optical Distance Meter). It is necessary to examine the calibration baselines regularly to keep the quality of the validation. The VLBI technique can examine and evaluate the calibration baselines. On the other hand, the following roles are expected of a compact VLBI antenna in the VLBI2010 project. In order to achieve the challenging measurement precision of VLBI2010, it is well known that it is necessary to deal with the problem of thermal and gravitational deformation of the antenna. One promising approach may be connected-element interferometry between a compact antenna and a VLBI2010 antenna. By measuring repeatedly the baseline between the small stable antenna and the VLBI2010 antenna, the deformation of the primary antenna can be measured and the thermal and gravitational models of the primary antenna will be able to be constructed. We made two prototypes of a transportable and compact VLBI system from 2007 to 2009. We performed VLBI experiments using theses prototypes and got a baseline length between the two prototypes. The formal error of the measured baseline length was 2.7 mm. We expect that the baseline length error will be reduced by using a high-speed A/D sampler

4-station ultra-rapid EOP experiment with e-VLBI technique and automated correlation/analysis

Since 2007, the Geospatial Information Authorityof Japan (GSI) and the Onsala Space Observatory(OSO) have performed the ultra-rapid dUT1 experiments,which can provide us with near real-timedUT1 value. Its technical knowledge has already beenadopted for the regular series of the Tsukuba-Wettzellintensive session. Now we tried some 4-station ultrarapidEOP experiments in association with Hobart andHartRAO so that we can estimate not only dUT1 butalso the two polar motion parameters. In this experimenta new analysis software c5++ developed by theNational Institute of Information and CommunicationsTechnology (NICT) was used. We describe past developmentsand an overview of the experiment, and concludewith its results in this report

4-station ultra-rapid EOP experiment with e-VLBI technique and automated correlation/analysis

Since 2007, the Geospatial Information Authorityof Japan (GSI) and the Onsala Space Observatory(OSO) have performed the ultra-rapid dUT1 experiments,which can provide us with near real-timedUT1 value. Its technical knowledge has already beenadopted for the regular series of the Tsukuba-Wettzellintensive session. Now we tried some 4-station ultrarapidEOP experiments in association with Hobart andHartRAO so that we can estimate not only dUT1 butalso the two polar motion parameters. In this experimenta new analysis software c5++ developed by theNational Institute of Information and CommunicationsTechnology (NICT) was used. We describe past developmentsand an overview of the experiment, and concludewith its results in this report