• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.2
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• pp.197-203
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• 2005

Dredging and reclaiming on coast, harbor construction etc. of when construct, the interest about efficiency and accuracy of sounding by measurement condition very rise. However, there are only a few studies on the accuracy improvement concerning water depth sounding condition. In this study, among the precision decline main causes of sounding, 1 suggested the characteristics of sounding data acquired by echo sounder with increasing of turbidity and the critical turbidity range under a given transducer frequency. For this, I acquired sounding data by inputting turbidity inducer artificially in artificial water tank. And then achieved regression analysis. Conclusion are as following Sounding Capabilities can be divided into three ranges according to the turbidity . normal range, critical range and the range where data can not be obtained by an echo sounder. When the turbidity exceeds $217\~259$ NTU which was considered as critical range, depth sounding was impossible.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2010.04a
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• pp.143-144
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• 2010

Nowadays, sounding is done by either manually on a boat or through the use of survey. These existing measures are considered to be very inefficient. they are not only greatly limited by environmental circumstances but also requires much of time, expenses, and manpower. Therefore, there emerges a greater need for a new sounding system which will allow us to measure the depth of water, less affected by financial and environmental restrictions, within a short period of time. This is a base study for developing an automatic sounding system, which will enhance the advantages of manned sounding and unmanned sounding, raise the effectiveness and economic efficiency, and acquire more precise data.

• Journal of Communications and Networks
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• v.5 no.4
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• pp.309-318
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• 2003

This paper presents an in-depth study of a UWB indoor radio channel between 1 and 9 GHz, which was used for the subsequent development of a new statistical UWB multipath channel model, focusing on short range indoor scenarios. The channel sounding process was carried out covering different indoor environments, such as laboratories, halls or corridors. A combination of new and traditional parameters has been used to accurately model the channel impulse response in order to perform a precise temporal estimation of the received pulse shape. This model is designed specifically for UWB digital systems, where the received pulse is correlated with an estimated replica of itself. The precision of the model has been verified through the comparison with measured data from equivalent scenarios and cases, and highly satisfactory results were obtained.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.1
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• pp.1-8
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• 2005

Multi-beam echo sounder is more precise and efficient than single beam echo sounder relatively because it is able to survey a wide area with 3 times or 4 times swath width as much as the depth of water using multi-beam echo sounder. It is sure to be needed to control supplementary equipment accurately, however, because the principle of creation and measurement of the beam is elaborate and influenced a great deal by vessel's motion. We analyzed using visual and statistical methods in both sections of the depth of water where were the places of the center of the beam and ± 45° angles from the central beam to improve the precise of Multi-beam echo sounder in this study. In result, it was required to control supplementary equipment because of errors from the vibration of an inertia governor and misalignment of extra units. Therefore, we reduced the vibration from the vessel's engine by sticking rubbers to the inertia governor and measured the offset values of extra units accurately, converted them to the values of horizontal position and lined up. In result, the precise in sounding the depth at the place of ± 45° from the center of the beam was improved from the level of the 1st order to the special order in a hydrographic survey of the IHO S44 standards and a phenomenon of ripple patterns in the overlapped area by misalignment was decreased remarkably.

• 한국지구물리탐사학회:학술대회논문집
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• 2008.10a
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• pp.93-96
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• 2008

We analyze a precise seabed feature around the Hupo Bank by using Multi-beam echosounder. Multi-beam echosounder system can observe the topography undulation according to the navigation of the survey ship by shooting wide beam. It is possible to embody a precision seabed feature because it can be make high density of incompletion depth sounding between survey lines. Through this survey, there is the Hupo Bank which is 84 km long, 1-15 km wide, 5.3-160 m deep in the center, at the west is moat, at the east is scarp and submarine canyon. The top of the Hupo Bank is the Wangdol reef that has 5.3 m in depth of water at least. Moat in survey area is 30 m long, and 30-40 m wide and has a depressed channel. The gap of depth of water in scarp is approximately 60 m and shows a characteristic of cuttig plane. Submarine canyon is 3.5 - 13.5 km wide.

• Journal of Korean Society for Geospatial Information Science
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• v.11 no.3 s.26
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• pp.23-34
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• 2003

Currently, the efficiency of GPS has been increased in the various precise survey like as the control survey and the navigation etc. Also, it is widely used in the deformation analysis of the structure, the measurement of the marine tides, the measurement of the river level and the topographic monitoring of seabed or riverbed by combined the measurement equipment for depth. In this study, we intend to increase in efficiency of the topographic monitoring of seabed or riverbed by combined with DGPS, RTK GPS and echo sounder. For this study, we defined the error correction of the echo sounder with the experiment of water tank which is considered the characteristic of estuary riverbed and then we developed the s/w for 3-dimensional monitoring of estuary riverbed and applied the s/w to field test and improved the various problems. On analyzing topography of estuary riverbed by combined GPS with echo sounder, the draught error which is yielded to change of length from the water surface by the movement of survey vessel to the end of the transducer was eliminated by geometrical rearrangement and we defined the correction formula $z=BM+SAH-DBR_{(i)}-DRT-ED$. The sounding error about the echo sounder and characteristic of estuary riverbed was found by understanding the relation of average diameter ind residual error and we defined correction formula, $Y=0.00474{\ast}ln(X)-0.0045$ by the regression analysis. and then we verified applicability of correction formula.