GPS

Question 1

What is RAIM?

Answer 1

-Receiver autonomous integrity monitoring
-Monitors the integrity of satellite strength
-Needs 4 satellites for fault detection
-Needs 5 satellites for fault detection and exclusion
*Because we have a baro-aiding altimeter

Question 2

What is WAAS

Answer 2

-Wide Area Augmentation System
-Corrects for errors in GPS system (behind the atomic clock)

Question 3

WAAS Corrections

Answer 3

GPS is accurate to 50ft
WAAS accurate to 10ft

Question 4

3 Components of GPS?

Answer 4

1. Space: Satellites (24 total) (6 orbital phases)
2. Control: Ground stations, master control station, monitoring stations
3. User: G1000, iPhone

Question 5

How does GPS work

Answer 5

Pseudoranging:
Distance and Time (Beam sends out to the plane, then back to us) (THINK DME)

Trilateration:
-3 satellites give us a 2D position of where we are
-4 or more satellites give us 3D position of where we are (altitude)