3:30 PM - 5:00 PM
[SGD01-P13] Status report of GSI VLBI activity in Ishioka VLBI station
Keywords:VLBI, VGOS, Local-tie survey
The International VLBI Service for Geodesy and Astrometry (IVS) promotes VLBI Global Observing System (VGOS; Petrachenko et al., 2009), which is a part of Global Geodetic Observing System (GGOS). The VLBI station in the Ishioka Geodetic Observing Station in GSI (hereafter Ishioka station) meets the VGOS requirements and participates in international VLBI observations coordinated by IVS. The goals of VGOS are to achieve: 1-mm position accuracy on global scales, continuous measurements for time series of station positions as well as Earth Orientation Parameters, and turnaround time to initial geodetic results of less than 24 hours. To achieve these goals, the VGOS stations should be equipped with antennas with high slewing rate, receivers for broadband observations (2-14 GHz) and high speed recording systems up to 32 Gbps.
Recently, the number of VGOS stations has gradually increased. In 2030, the total number is estimated to become approximately 30 (Haas and Behrend, 2022). IVS conducts both VGOS observations and legacy S/X observations. The Ishioka station participates in VGOS observations for several month every year and participates in legacy S/X observations for the rest of the period with switching its observation system. It is to be desired that Ishioka station should be operated without interruption between the periods of S/X and VGOS observation. As one of the possible solutions to the problem, we tested a method to transform VLBI data with linear polarization into those with circular polarization. In addition to that, we introduced a new backend system such as a new sampler DBBC3 and a recording system Flexbuff, in order to replace an old system and to increase the total volume of storage in Ishioka station.
Ishioka Geodetic Observing Station also has GNSS stations in the site, one of which is registered as an IGS station “ISHI”. GSI conducts local-tie survey to determine the local tie vector between the VLBI and GNSS reference points on a regular basis. The result of the local-tie survey in 2018 and 2020 was submitted to International Earth Rotation and Reference Systems Service (IERS) and contributed to construction of ITRF2020. This is the first time for Ishioka to submit the result of the local-tie surveys.
This talk will summarize these recent VLBI activities of Ishioka station.
Recently, the number of VGOS stations has gradually increased. In 2030, the total number is estimated to become approximately 30 (Haas and Behrend, 2022). IVS conducts both VGOS observations and legacy S/X observations. The Ishioka station participates in VGOS observations for several month every year and participates in legacy S/X observations for the rest of the period with switching its observation system. It is to be desired that Ishioka station should be operated without interruption between the periods of S/X and VGOS observation. As one of the possible solutions to the problem, we tested a method to transform VLBI data with linear polarization into those with circular polarization. In addition to that, we introduced a new backend system such as a new sampler DBBC3 and a recording system Flexbuff, in order to replace an old system and to increase the total volume of storage in Ishioka station.
Ishioka Geodetic Observing Station also has GNSS stations in the site, one of which is registered as an IGS station “ISHI”. GSI conducts local-tie survey to determine the local tie vector between the VLBI and GNSS reference points on a regular basis. The result of the local-tie survey in 2018 and 2020 was submitted to International Earth Rotation and Reference Systems Service (IERS) and contributed to construction of ITRF2020. This is the first time for Ishioka to submit the result of the local-tie surveys.
This talk will summarize these recent VLBI activities of Ishioka station.