FS FS - Fundamentals of Surveying Hydrographic Surveying 2

Question 1

What is the purpose of tide gauge readings during a hydrographic survey?

Accepted Answer

To reduce soundings to a common chart datum

Answer

Tide gauge readings record water level changes so that soundings collected at various tidal states can be reduced to a common chart datum like MLLW.

Question 2

What is a bar check in echo sounder calibration?

Accepted Answer

Lowering a plate to known depths to verify sounder accuracy

Answer

A bar check involves lowering a metal plate to known depths and comparing the echo sounder's readings to verify its accuracy and account for sound velocity variations.

Question 3

What is the approximate velocity of sound in water used for echo sounder calculations?

Accepted Answer

1,500 m/s

Answer

The standard velocity of sound in seawater used for echo sounder calculations is approximately 1,500 m/s, though actual velocity varies with temperature and salinity.

Question 4

What is side scan sonar primarily used to detect in hydrographic surveys?

Accepted Answer

Submerged objects and seafloor texture

Answer

Side scan sonar emits acoustic energy to the sides of the survey vessel, producing image-like data that reveals submerged objects, wreckage, and bottom characteristics.

Question 5

What is a lead line in hydrographic surveying?

Accepted Answer

A weighted rope marked at intervals for manually measuring water depth

Answer

A lead line is a weighted rope or wire marked at regular intervals, historically used to manually measure water depth before electronic instruments were available.

FS - Fundamentals of Surveying Exam Practice Test

FS - Fundamentals of Surveying Exam Practice Test

FS FS - Fundamentals of Surveying Hydrographic Surveying 2