Observing seafloor crustal deformation is often composed of acoustic ranging and GPS positioning techniques, which involves positioning of a single seabed transponder. Generally, the positional uncertainty of the seabed transponder is evaluated in terms of the slant range residuals. In order to further verify the relative positioning accuracy between seabed transponders, this study designed and fabricated a transponder lander. Three transponders were mounted on the lander to form a triangle with sides 1.505, 1.505 and 1.160 m. In addition, a data acquisition and logging system is developed to collect the lander¡¦s attitude, including pitch, roll, heading, and accelerations in three orthogonal axes. A field experiment to verify the relative positioning accuracy between seabed transponders was carried out off the coast of Kaohsiung Harbor, Taiwan. The transponder lander was deployed on the seabed at a water depth of about 300 m. Based on the attitude data collected by the logging system, the heading, pitch and roll of the transponder lander on the seabed are 123.5 degrees, 0.63 degrees and 0.62 degrees, respectively. A vessel was sailed along predetermined paths to collect observations of GPS and acoustic slant range. Then, an optimization technique combined with ray tracing method was used to estimate the positions of three transponders. The position estimates of the three transponders form a triangle with sides 1.533, 1.518 and 1.184 m, which shows that, comparing with the true values, the relative positioning error between transponders is less than 3 cm. Furthermore, based on the estimates of the transponder positions, the heading, pitch and roll of the transponder lander are calculated as 120.45 degrees, 6.43 degrees and 2.51 degrees, respectively, which are in good agreement with that measured by the attitude logging system. The experimental and evaluation results indicate that the optimization technique along with the ray tracing method is practical for precisely estimating the transponder position.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0811109-163540 |
| Date | 11 August 2009 |
| Creators | Jang, Jia-Pu |
| Contributors | Chau-Chang Wang, Shiahn-Wern Shyue, Hsin-Hung Chen |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0811109-163540 |
| Rights | withheld, Copyright information available at source archive |
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