Navigation and GPS Systems Flashcards
7 cards from real UAG practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Navigation and GPS Systems flashcards as text
What minimum number of GPS satellites must a receiver have line-of-sight to in order to calculate a three-dimensional position fix?
Answer: 4 satellites
A GPS receiver needs signals from at least 4 satellites to calculate latitude, longitude, altitude, and time simultaneously for a 3D position fix.
What does WAAS stand for in the context of GPS navigation?
Answer: Wide Area Augmentation System
WAAS (Wide Area Augmentation System) is an FAA satellite-based augmentation system that improves GPS accuracy for aviation use to approximately 1–3 meters.
Which FAA publication would a remote pilot check to learn about scheduled GPS signal outages or testing in a specific area?
Answer: NOTAMs (Notices to Air Missions)
NOTAMs (Notices to Air Missions) are used to inform pilots, including remote pilots, of GPS anomalies, outages, and testing affecting navigation.
Magnetic variation (declination) is best defined as:
Answer: The angular difference between true north and magnetic north at a given location
Magnetic variation is the angular difference between true geographic north and magnetic north, which varies by location and changes slowly over time.
What is Receiver Autonomous Integrity Monitoring (RAIM)?
Answer: A GPS feature that allows receivers to detect faulty satellite signals
RAIM is a GPS receiver function that cross-checks multiple satellite signals to detect and exclude faulty signals, providing integrity monitoring without external input.
When a UAS operating in GPS-assisted flight mode suddenly loses its GPS signal, what is the most likely immediate response of a standard autopilot system?
Answer: The UAS will switch to attitude/manual mode and may drift with wind
Most UAS autopilots transition to attitude (stabilized) mode when GPS is lost, meaning the aircraft can maintain attitude but will drift with wind since there is no position hold.
On a VFR sectional chart, what do isogonic lines represent?
Answer: Lines connecting points of equal magnetic variation
Isogonic lines on sectional charts connect points of equal magnetic variation (declination), helping pilots convert between true and magnetic headings.