GNSS Basics
This acronym stands for the full family of satellite navigation systems around the world.
What is GNSS?
This real-time correction method provides centimeter-level accuracy.
What is RTK (Real-Time Kinematic)?
This popular U.S. datum differs from WGS84 by up to 2 meters.
What is NAD83?
GNSS devices should be left to "settle" for this many minutes before collecting points on a cold start.
What is up to 10 minutes?
The Prime Meridian and Equator intersect at this geographic coordinate.
What is (0°, 0°)?
The number of satellites required for full operational capability of the U.S. GPS constellation.
What is 24?
SBAS stands for this type of augmentation system.
What is Satellite-Based Augmentation System?
This is the main reason we need map projections when working with 2D maps.
What is the Earth is a 3D shape (not flat)?
This physical point on a GNSS receiver is used to calculate positions.
What is the Antenna Reference Point (ARP)?
The height measured from the ellipsoid surface is called this.
What is ellipsoidal height?
The name of the Russian GNSS constellation.
What is GLONASS?
This type of RTK status means the receiver is close to a fix, but not fully locked.
What is RTK Float?
This is the shape used by satellites and math models to represent the Earth.
What is an ellipsoid?
Metal fences, vehicles, and buildings can distort GNSS signals in this way.
What is signal reflection or interference?
This height uses gravity and is considered the "mean sea level" height.
What is orthometric height?
The first country to launch a satellite navigation system.
What is the United States?
A common error caused when GNSS signals bounce off buildings or metal surfaces.
What is multipath error?
This vertical datum is the most commonly used in the U.S. as of 2024.
What is GEOID18?
True or False: Bluetooth range impacts the positional accuracy of a GNSS device.
What is False?
This kind of shift occurs when converting between datums like NAD83 and WGS84.
What is a datum shift?