FUNDAMENTAL SURVEYING Surveying Equipment & GPS/GNSS 3

Question 1

What is LiDAR in the context of modern surveying?

Accepted Answer

Light Detection and Ranging — a laser-based system for collecting dense 3D point clouds

Answer

LiDAR emits laser pulses and measures return times to generate millions of 3D points, creating highly accurate elevation models and site maps.

Question 2

What is 'photogrammetry' in surveying?

Accepted Answer

Deriving measurements and maps from photographs or imagery

Answer

Photogrammetry extracts spatial measurements and creates maps and 3D models from overlapping photographs or drone imagery.

Question 3

What is a 'control survey'?

Accepted Answer

A high-accuracy survey establishing horizontal and/or vertical positions to control subsequent surveys

Answer

A control survey establishes a network of accurately positioned monuments that serve as the framework for all subsequent surveys in an area.

Question 4

What is the geoid in the context of vertical datums?

Accepted Answer

An equipotential surface approximating mean sea level used as the reference for orthometric heights

Answer

The geoid is an irregular equipotential surface of Earth's gravity field that closely approximates mean sea level and serves as the reference for orthometric (elevation) measurements.

Question 5

What does the 'N value' (geoid undulation) represent in GPS surveying?

Accepted Answer

The vertical separation between the ellipsoid and the geoid at a given location

Answer

The geoid undulation N = ellipsoidal height minus orthometric height, and is used to convert GPS ellipsoidal heights to practical sea-level (NAVD 88) elevations.

FUNDAMENTAL SURVEYING Practice Test

FUNDAMENTAL SURVEYING Practice Test

FUNDAMENTAL SURVEYING Surveying Equipment & GPS/GNSS 3