• Comparison study of VLBI and GPS carrier phase frequency transfer - Part II -

      Takiguchi, H; Koyama, Y; Ichikawa, R; Gotoh, T; Ishii, A; Hobiger, T (National Institute of Information and Communications Technology (NIICT), 2009)
      To show the frequency stability of local baseline, we carried out long term VLBI experi- ment together with GPS and DMTD measurement. And, we compared the results provided from these three techniques. The results are ...
    • Comparison study of VLBI and GPS carrier phase frequency transfer using IVS and IGS data

      Takiguchi, H; Koyama, Y; Ichikawa, R; Gotoh, T; Ishii, A; Hobiger, T; Hosokawa, M (National Institute of Information and Communications Technology (NIICT), 2008)
      We compare the frequency transfer pre- cision between VLBI and GPS carrier phase using IVS and IGS observation data in order to confirm the potential of VLBI time and frequency transfer. The results show that VLBI time ...
    • Comparison with GPS Time Transfer and VLBI Time Transfer

      Takiguchi, H; Hobiger, T; Ishii, A; Ichikawa, R; Koyama, Y (AUT UniversityNational Institute of Information and Communications Technology (NIICT), 2007)
      To compare the results with Global Po- sitioning System (GPS) Time Transfer and Very Long Baseline Interferometry (VLBI) Time Trans- fer, we carried out the geodetic VLBI experi- ments for four times. The averaged formal ...
    • Development of the compact VLBI system for calibrating GNSS and EDM devices

      Ichikawa, R; Ishii, A; Takiguchi, H; Takefuji, K; Ujihara, H; Koyama, Y; Kondo, T; Kurihara, S; Miura, Y; Kawabata, R; Kokado, K; Machida, M; Takashima, K; Fujisaku, J; Tanimoto, D; Nozawa, K (National Institute of Information and Communications Technology (NICT), 2010)
      We are developing a compact VLBI (Very Long Baseline Interferometry) system with 1.6 m diameter aperture dish in order to provide reference baseline lengths for calibration. The reference baselines are used to validate ...
    • Evaluation of a laser-pumped Cs gas-cell frequency standard on geodetic VLBI

      Ishii, A; Ichikawa, R; Takiguchi, H; Kuboki, H; Sekido, M; Koyama, Y; Ohuchi, Y (Geodetic Society of Japan, 2008)
      The laser-pumped Cs gas-cell type atomic frequency standard (hereafter, we called the "Cs gas-cell oscillator") , this was developed in recent years, has a stability between a hydrogen maser oscillator and a Cs beam-type ...
    • Evaluation of the new approach to improving compact-compact antenna baseline in VLBI

      Takiguchi, H; Ishii, A; Ichikawa, R; Koyama, Y (National Institute of Information and Communications Technology (NICT), 2009)
      No abstract
    • Inter-comparison study of time and frequency transfer between VLBI and other techniques (GPS, ETS8(TCE), TW(DPN) and DMTD)

      Takiguchi, H; Kimura, M; Kondo, T; Ishii, A; Hobiger, T; Ichikawa, R; Koyama, Y; Takahashi, Y; Nakagawa, F; Nakamura, M; Tabuchi, R; Tsuchiya, S; Hama, S; Gotoh, T; Fujieda, M; Aida, M; Li, T; Amagai, J (International VLBI Service (IVS), 2011)
      We carried out the intercomparison ex- periments between VLBI and other techniques to show the capability of VLBI time and frequency transfer by using the current geodetic VLBI tech- nique and facilities as the summary of ...
    • Intercomparison between VLBI frequency transfer and other techniques

      Takiguchi, H; Koyama, Y; Ichikawa, R; Gotoh, T; Ishii, A; Hobiger, T; Fujieda, M; Amagai, J; Hosokawa, M (National Institute of Information and Communications Technology (NICT), 2010)
      No abstract
    • Precise time transfer by Means of Geodetic VLBI Technique - Part II -

      Takiguchi, H; Koyama, Y; Ichikawa, R; Ishii, A; Hobiger, T (The Geodetic Society of Japan, 2007)
      No abstract.
    • Short term position variation due to the atmospheric loading near semi-closed sea

      Takiguchi, H; Hobiger, T; Otsubo, T; Ichikawa, R; Koyama, Y; Fukuda, Y (Japan Geoscience Union, 2007)
      No abstract
    • Time and frequency transfer using the telecommunication satellites for the long baseline interferometry

      Takiguchi, H; Amagai, J; Gotoh, T; Aida, M; Ichikawa, R; Kondo, T (Geodetic Society of Japan, 2010)
      No abstract.
    • VLBI and GPS carrier phase time and frequency transfer

      Takiguchi, H; Koyama, Y; Ichikawa, R; Gotoh, T; Ishii, A; Hobiger, T (National Institute of Information and Communications Technology (NICT), 2010)
      As one of the new frequency transfer technique to compare the next highly stable frequency standards, we proposed the geodetic VLBI technique. We evaluated the ability of VLBI frequency transfer by comparison with GPS ...
    • VLBI measurements for frequency transfer

      Takiguchi, H; Koyama, Y; Ichikawa, R; Gotoh, T; Ishii, A; Hobiger, T; Hosokawa, M (National Institute of Information and Communications Technology (NICT), 2010)
      We carried out the intercomparison experiment between VLBI and GPS to show that VLBI can measure the correct time difference. We produced an artificial delay change by stretching the Coaxial Phase Shifter which was inserted ...
    • VLBI measurements for Frequency Transfer

      Takiguchi, H; Koyama, Y; Ichikawa, R; Gotoh, T; Ishii, A; Hobiger, T; Hosokawa, M (National Institute of Information and Communications Technology (NICT), 2008)
      We compare the frequency transfer precision between VLBI and GPS carrier phase using IVS and IGS observation data in order to confirm the potential of VLBI time and frequency transfer. The results of the VLBI frequency ...
    • VLBI Measurements for Time and Frequency Transfer

      Takiguchi, H; Koyama, Y; Ichikawa, R; Ishii, A; Hobiger, T; Hosokawa, M (Japan Society of Applied Physics (JSAP), 2008)
      原子泉型周波数標準器及び光周波数標準器の開発が世界各国で進められているが,このような 高精度の周波数標準器を比較する新しい時刻比較技術の開発も必要である.宇宙測地技術のひ とつであるVLBI は,遥か彼方の天体から放射される電波を,複数のアンテナで受信し,その 到達時間の差(遅延時間)を精密に計測している.解析では,遅延時間を各種物理パラメータと, 局の位置,速度,大気遅延と共に,基準局に対する観測局のクロックオフセットを未知パラメ ...
    • VLBI measurements for time and frequency transfer (from the EFTF forum, 2008)

      Takiguchi, H; Koyama, Y; Ichikawa, R; Gotoh, T; Ishii, A; Hobiger, T; Hosokawa, M (European Frequency and Time Forum, 2008)
      Modern cold-atom-based frequency standards have already archived the uncertainty of 10-15at a few days. Moreover cold-atom-based optical clocks have the potential to realize the uncertainty of from 10-16 to 10-17 level ...
    • VLBI Measurements for Time and Frequency Transfer (from the JGU meeting, 2008)

      Takiguchi, H; Koyama, Y; Ichikawa, R; Ishii, A; Hobiger, T; Hosokawa, M (Japan Geoscience Union, 2008)
      Modern cold-atom-based frequency standards have already archived the uncertainty of 10−15 at a few days. Moreover coldatom- based optical clocks have the potential to realize the uncertainty of from 10−16 to 10−17 level ...
    • VLBI measurements for time transfer between time and frequency laboratories

      Takiguchi, H; Koyama, Y; Ichikawa, R; Gotoh, T; Ishii, A; Hobiger, T (American Geophysical Union, 2007)
      In the usual geodetic VLBI analysis, clock offsets and their rates of change at participating stations except for the reference station are estimated. The averaged formal error (1σ) of the clock offsets is typically about ...