HR: 0800h
AN: G21A-0144    [Abstracts]
TI: Accuracy Evaluation of Kinematic GPS with a Moving Object for Observing Sea-floor Crustal Deformation
AU: * Takatani, K
EM: kazunori@eps.nagoya-uac.jp
AF: Graduate School of Environmental Studies, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602 Japan
AU: Ando, M
EM: ando@seis.nagoya-u.ac.jp
AF: Graduate School of Environmental Studies, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602 Japan
AU: Tadokoro, K
EM: tad@seis.nagoya-u.ac.jp
AF: Graduate School of Environmental Studies, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602 Japan
AU: Okuda, T
EM: okuda@seis.nagoya-u.ac.jp
AF: Graduate School of Environmental Studies, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602 Japan
AU: Ikuta, R
EM: ryoya@seis.nagoya-u.ac.jp
AF: Graduate School of Environmental Studies, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602 Japan
AU: Sugimoto, S
EM: sugimoto@eps.nagoya-u.ac.jp
AF: Graduate School of Environmental Studies, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602 Japan
AU: Yada, K
EM: yada@eps.nagoya-u.ac.jp
AF: Graduate School of Environmental Studies, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602 Japan
AB: In order to monitor seafloor crustal deformation, we have developed a system with kinematic GPS positioning and acoustic ranging. The major error factors of the present system related to locate seafloor transponders are: 1) estimations of seawater acoustic velocities, 2) detection of acoustic signals, and 3) positioning by kinematic GPS. In our previous study, an accuracy evaluation experiment of kinematic GPS was conducted with baseline lengths of 15km, 30km, and 90km. As a result, the error of kinematic GPS is minimized by 1-2cm when baseline length is 10-30km especially with small satellite arrangement error. In this meeting, we will show the result of our recent experiments with extended baseline lengths. Moreover, this experiment also investigated for horizontal as well as vertical accuracy by moving a rover antenna along a lifting device. The result of this experiment is important and would benefit the marine observation to reevaluate accuracy classified by baseline length of kinematic GPS. This experiment was conducted as follows: we constructed five baselines with varying lengths (30, 60, 90, 110 and 150km). ROVER, an antenna moving on a rail way, was located at Nagoya Univ. In order to know the error of an internal clock of receiver, the external frequency clock was attached in the receiver of each point. The data were logged at 1 second interval with the minimum elevation of GPS satellites as 15 degree. Moreover, in consideration of satellite arrangement, we experimented only during the time with PDOP<=2. A software RTD was used for analysis of kinematic GPS and data of precise orbits provided by IGS was also used. Bernese version 4.2 was used for the position determination of base stations and the rail with one week data. In accuracy evaluation, the position of an antenna was estimated on the rail in reference with the base station installed in Nagoya University (near ROVER). The position of the antenna was also set to a true coordinate value wherein the distance between the true value and coordinate values were calculated with each baseline solution.
DE: 3000 MARINE GEOLOGY AND GEOPHYSICS
DE: 1200 GEODESY AND GRAVITY
SC: Geodesy [G]
MN: 2004 AGU Fall Meeting