Measurement and Data Collection Flashcards
6 cards from real FUNDAMENTAL SURVEYING practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Measurement and Data Collection flashcards as text
The sensitivity of a level bubble is expressed as the angle subtended per division. A 20″/2mm bubble is considered:
Answer: Very sensitive
A 20 arc-seconds per 2mm division bubble is considered very sensitive and suitable for precise leveling work.
What is a turning point (TP) in differential leveling?
Answer: An intermediate point used to carry elevations forward
A turning point is an intermediate point on which both a foresight and a backsight are taken to carry elevations from one instrument setup to the next.
What type of error is eliminated by observing both face-left and face-right with a theodolite?
Answer: Systematic errors including collimation and trunnion axis errors
Reversing the telescope (face-left and face-right) eliminates systematic instrument errors such as collimation, trunnion axis, and circle eccentricity errors.
In GNSS surveying, what is 'PDOP' and why does it matter?
Answer: Position Dilution of Precision — lower values indicate better satellite geometry and higher accuracy
PDOP (Position Dilution of Precision) quantifies satellite geometry; lower PDOP means satellites are well distributed and position accuracy is higher.
What is the primary advantage of using RTK (Real-Time Kinematic) GNSS over static GNSS?
Answer: Real-time centimeter-level positions without post-processing
RTK GNSS provides centimeter-level accuracy in real time by transmitting corrections from a base station to a rover.
What is a geodetic datum?
Answer: A mathematical reference surface and coordinate system used to define positions on Earth
A geodetic datum is a mathematical reference model (ellipsoid + origin) that defines the coordinate system for expressing geographic positions.