What Is Hydrographic Survey
The International Hydrographic Organization (IHO), defines hydrographic as “the branch of applied science which deals with the measurement and description of the physical features of the navigable portion of the earth’s surface (seas) and adjoining coastal areas, with special reference to their use for the purpose of navigation.”
The physical features which affect maritime navigation, marine construction, dredging, offshore oil exploration/offshore oil drilling and related activities. Strong emphasis is placed on soundings, shorelines, tides, currents, seabed and submerged obstructions that relate to the previously mentioned activities.
The hydrographic survey activities are described as below:
Bathymetry Survey
Single beam seabed sounding is to provide topographic of the seabed.
Multibeam Survey
Multibeam seabed swath sounding is to provide topographic of the seabed and also can generate image.
Side Scan Sonar Survey (SSS)
SSS is seabed scanning activity by using sonar technology. Analysis of imaging studies, It is able to provide understanding of the differences in material and texture type of the seabed. This data can be used for pipeline or cable lay survey.
Sub bottom Profiler
Sounding penetrate till 40m below seabed to investigate soil layer futures.
Grab Sample
The purpose is to grab soil sample for soil verification.
Tide Measurement
Tidal Measurement is to get the value of chart datum or mean sea level by install the tide gauge station. In order to get the exact or actual value of chart datum it needs 19 years of observation. The minimum for installation is 30 days of observation, than the periodic chart datum can be calculated. This can help construction job such as platform installation by give the datum reference