CST GPS & GNSS Surveying Technologies 3

Question 1

In RTK GPS surveying, what must be successfully completed before the receiver can deliver centimeter-level accuracy?

Accepted Answer

Integer ambiguity resolution (initialization)

Answer

A magnetic declination calibration

Answer

A vertical datum transformation to NAVD 88

Answer

A geoid undulation download from NGS

Question 2

What is a CORS station in the context of GPS surveying infrastructure?

Accepted Answer

A Continuously Operating Reference Station providing permanent GPS data

Answer

A Coordinate Output Reference System receiver

Answer

A Corrected Orbital Ranging Signal transmitter

Answer

A Combined Observation and Recording System

Question 3

When converting GPS ellipsoidal heights to orthometric (mean sea level) heights, what resource does a surveyor use?

Accepted Answer

A geoid undulation model such as GEOID18

Answer

A magnetic declination table from NOAA

Answer

A tidal benchmark correction from NOAA CO-OPS

Answer

A Helmert 7-parameter datum transformation

Question 4

Which primary operational advantage does GNSS offer over traditional total station traversing on large-scale projects?

Accepted Answer

GNSS allows positions to be determined without intervisibility between stations

Answer

GNSS eliminates the need for any field crew

Answer

GNSS provides direct line-of-sight distance measurements

Answer

GNSS is more accurate than total stations for distances under 100 meters

Question 5

During an RTK GPS survey, the PDOP value rises to 9.2. What is the appropriate course of action?

Accepted Answer

Suspend observations and wait for satellite geometry to improve

Answer

Continue observations, since PDOP only affects static surveys

Answer

Switch the receiver to single-frequency L1 mode only

Answer

Raise the antenna on a taller range pole to improve signal reception

Question 6

In RTK GPS processing output, what does a 'fixed solution' signify compared to a 'float solution'?

Accepted Answer

Carrier phase integer ambiguities have been resolved, yielding centimeter-level accuracy

Answer

The receiver antenna is physically secured to a tripod rather than a range pole

Answer

The base station coordinates have been fixed to a national control monument

Answer

The project coordinates have been transformed to a fixed state plane system

Question 7

What is the primary limiting factor that determines the maximum practical baseline length for reliable RTK GPS surveys?

Accepted Answer

Ionospheric conditions and the distance-dependent difference between base and rover

Answer

The number of GNSS constellations the receiver can track

Answer

The type of antenna used at the base and rover stations

Answer

The age and firmware version of the GPS receiver hardware