Crustal Deformation Measurement in the Metropolitan Area Real-Time VLBI System Software -- RKATS

M. Sekido(sekido(AT), T.Kondo, Y.Koyama
Kashima Space Research Center
Communications Research Laboratory
893-1 Hirai, Kashima, Ibaraki 314, Japan

H.Kiuchi, M.Imae
Communications Research Laboratory
4-2-1 Nukui-kita, Koganei, Tokyo 184, Japan

Kety Co. Ltd.

Abstract: Real time VLBI data processing software RKATS is under the development by Communications Research Laboratory and Kety Co.Ltd. It is designed as automatic VLBI data processing management software. The overview is described in this article.

1. Introduction

Key Stone Project (KSP) is a trial to catch the pre-seismic crustal deformation around Tokyo metropolitan area by using VLBI and SLR techniques (Figure.1). Daily observation with 4 VLBI stations has started as test run from this summer.

Figure 1. Overview of Key Stone Project.

In normal VLBI experiment, the observed data have to be recorded on magnetic tapes and they have to be correlated after transportation to central correlation center. In the earliest case in the KSP, 1-2 days were necessary for data processing and analysis of the data. Now the correlation system of KSP is semi-automated by DMS (tape auto-changer) and data processing and analysis software, but it even needs a support by operator for transportation of tapes, tape mounting to auto-changer, and correlation setup.

Recently, real-time data transportation by using Asynchronous Transport Mode (ATM) with high speed optical fiber link has become available in laboratory level. We have started Real-time VLBI based on co-laboration between CRL and NTT (Nippon Telegraph and Telephone Corporation). Data transfer with communication network gives a possibility of full-automated VLBI observation system. It release an operator from transportation of magnetic tapes and treatment of them.

Now a software RKATS (Real-time KATS) is under development for full automated VLBI data processing system, which controls real-time 6 baselines correlation, Bandwidth-synthesis treatment, and Mark-III database creation.

2. Functions of Real-Time-KATS (RKATS)

The RKATS is developed from a tape base VLBI data processing software KATS, which assist a operator in the work of correlation processing, database creation, and data backup. Both RKATS and KATS run on HP-UX workstation. Figure 2 shows a over view of the flow of data processing.

Figure 2. Real-time VLBI data flow.

The functions of RKATS are as follows:

The new data is analyzed by auto baseline analysis software. Then the baseline and station positions are determined. Final analysis is performed after the final value of Earth orientation parameter is provided from IERS.

Additionally RKATS has automatic data backup function by using DAT auto-changer. The capacity of it is about 12GB, which gives capability of more than 10 days of 24 hour experiment data storage.

3. Summary

Automatic Real-time VLBI data processing software RKATS is being developed for Key Stone Project. It is expected to run from the end of this year.


We appreciate Dr. Watanebe, Dr. Uematsu, and Dr. Hoshino in NTT Optical Network System laboratory for the assist of high performance ATM system for this project.

Updated on October 28, 1996. Return to CONTENTS