Global Nav Satellite System (GNSS)

Question 1

What frequency range do GNSS satelites transmit

Answer 1

UHF
Typically 1600MHz

Question 2

How many signals/satelites are required for a position fix

Answer 2

4

Question 3

What are the 3 main GNSS systems
1. USA
2. Russia
3. European

Answer 3

1. NAVSTAR
2. GLONASS
3. GALILEO

Question 4

What are 5 known errors with GNSS systems

Answer 4

1. Atmospheric Delays
2. Clock Errors
3. Orbit Uncertainty
4. Multi-path Errors
5. Receiver noise

Question 5

What is the range in meters for GNSS accuracy error with 4 satellites

Answer 5

10 - 30m

Question 6

Error correction in GNSS

What does SBAS stand for

Answer 6

Satillite Based Augmentation System

Question 7

Error correction in GNSS

What does WAAS stand for

Answer 7

Wide Area Augmentation System

Question 8

Error correction in GNSS

What does EGNOS stand for

Answer 8

Euro Geostationary Navigation Overlay Service

Question 9

What does DOP stand for

Answer 9

Dilution of Precision

Question 10

Position accuracy depends on satellite positions in what 3 positions

Answer 10

1. PDOP - Position
2. VDOP - Vertical
3. HDOP - Horizontal

Question 11

What is the purpose of Receiver Autonomous Integrity Monitoring (RAIM)

Answer 11

Ensures receiver can see correct number of satellites

Question 12

How many satellite signals must be seen for RAIM to perform fault detection

Answer 12

5

Question 13

How many satellite signals must be seen for RAIM to perform fault detection and exclusion

Answer 13

6

Question 14

Are GNSS systems approved as sole means of navigation by CAA

Answer 14

NO

Question 15

What is an issue with GNSS databases

Answer 15

Out of date quickly