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The Device used to transmit and receive an acoustic signal used for depth determination is called?
The primary lines surveyed with a single beam echo sounder are run ___ to the expected underwater contours.
To achieve total (100%) bottom coverage, multi-beam sounders are usually sailed on lines __ to the depth contours.
For Nautical Charts, the main reason depth is determined is for?
The most common acoustic instrument used for depth determination is a?
The two main calibrations required to be applied to single beam echo-sounders are?
Draft & Speed of sound
When using RTK GPS for depth determination for nautical charts, it is essential that one knows the __?
ellipsoid - chart datum seperation
We use __ SONAR techniques for depth determination.
Three parameters that affect the speed of sound in water are the mediums?
Temperature, Salinity, Pressure/Depth
A low frequency transducer has a ___ than a high frequency transducer
Longer Range and Lower Resolution
Sound speed in water is most affected by?
Mechanical, electrical and acoustic Doppler are all types of current meter technologies - this statement is ___?
Numerous difficulties associated with navigation and positioning may occur during the execution of a hydrographic survey - two of them are?
- 1. Antenna Interference
- 2. Electrical Noise
Two types of navigation & positioning tasks that may be required in the conduct of a hydrographic survey are?
Homing, Tracking, and Stationing
Canadian (Hydrographic Services) Standards fo Hydrographic Surveys are based on?
IHO as given in their S-44 Standard Document.
Canada's maritime/offshore boundaries are defined by?
Bilateral treaties & tide baselines
The horizontal component of the gravitational perturbing influences on the oceanic waters of the earth have the effect of moving the water horizontally piling it up in one direction the resulting horizontal motion is?
The tidal stream and the resulting piling up is any tide.
Two tide gauges that are considered useful for field survey are?
Bubbler & shore mounted underwater pressure transducer gauges.
What is IHO definition of Hydrography?
- -Relationship to landmasses
- -Sea features
- -Shape of ocean floor
The IHO hydrography parameters were created to encompass four additional items. What are they?
- -Tides & Waves
What are some Hydrographic Activities?
- -Exploration of Resources
- -Management of coastal areas
Elevations shown on Canadian HS charts relate to:
High water level
Water depths in Canada's oceans refer to:
Low Water Level
A Chart datum is?
A plane so low that the tide will seldom fall below it.