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46 st / October 2015 www.sea-technology.com 3DProfler software. The interface of the 3DProgrammer is simple and clear. Sampling parameters can be set in the up- per part of the window, while the start and end times for scheduling tasks can be set in the lower part of the window. When all the values are set, they can be written to the sonar. When the "Trigger" and "Connect" switches are off, the pro- gramming lead and USB cable may be disconnected from the PC frst, and then from the sonar. The main battery bin may be safely connected before the next scheduled wake- up time. Experimentation In September 2013, a test to observe scour and deposi- tion rate in shallow water was carried out by China's Second Institute of Oceanography, State Ocean Administration in the Pearl River Lingdingyang Estuary. In order to collect the dynamic relief data during a complete tidal cycle, our team decided to carry out a two-week-long, in-situ observation via an integrated submarine tripod system. During the investigation, the 3D profling sonar com- bined with other hydrodynamic investigation instruments, i.e., ADCP, acoustic Doppler velocimetry (ADV), CTD and marine altimeter, were bundled on a special submarine tri- pod and placed in the target area to acquire comprehensive deposition kinetic and topographic data. We set the wake-up interval of the 3D profling sonar to 1 hr. and the swath arc value to 20° in order to collect concen- trated relief data. The average water depth in the feld was about 10 m, and the water quality was very turbid. After half a month of in-situ observation, more than 380 raw data fles were recorded. Some individual fles were missed simultaneously; all the missed data belonged to the last three days of recording, which we attributed to weak- ening batteries. Overall, more than 97 percent data was recorded with relatively good quality. The stability of the equipment was proved. Data Analysis We picked several fles from the saved data to process and construct the digital terrain model (DTM). The contour maps were made subsequently, and the local relief changes could be identifed from the series graph. Because of the high velocity of the water and high preci- sion of the 3DProfler, relief data gathered within an hour showed apparent differences. As we expected, during a day, within two cycles of semidiurnal tide, the changes of the terrain in a certain site were more obvious. But for the recip- rocating motion of the spring tide in a week, relief changes in the same place are not very large. The extent of terrain changes during a week and during a day are similar. Further research is in progress by the way of comprehen- sive analysis with all the different sensor data. Judging from the current relief data, we suppose that changes of reliefs during a short period are mainly because of the roundtrip of tides, while changes over a long period may be mainly caused by the motion of current. Conclusion The 3D remote profling sonar has been proven to be an effcient, convenient, high-precision, sustainable tool for the in-situ observation of microrelief. It's not only a new tool but a new technique connecting marine geomorphology with called 3DProfler that can be used to control the sonar and display the raw data in real time. The sonar parameters can be set with the onscreen control panel and a sweep manu- ally started by pressing the green "Play" button. Key capture parameters can be set on the control subwindow, while other three subwindows can display the real-time images in dif- ferent perspectives. More parameters can be set selectively when the "Advance" button is pressed. Data will be acquired and saved promptly. Saved data can also be played back. Offine Mode Offine mode enables data acquisition via self-awaken- ing method. The 3DProgrammer is needed instead of the DProfler interface for online data collection. &RUH; 6DPSOLQJ 0DGH (DV\ 9LEH&RUH-;' Near zero core compression More accurate vertical record Core samples to 7 m long from 65 m depths Undisturbed 76mm or 100mm dia. Samples Performance of larger Vibracores Man transportable safe 24 vdc operation Designed for small boat use Pre/Post-dredge sampling Sedimentation rate surveys Environmental remediation Capping studies Soil mechanics European Sales via www.Aquiferadvies.nl Specialty Devices, Inc. 972 429 7240 2905 Capital St., Wylie, Texas, USA www.Specialtydevices.com Made in USA