Course: GPS-WAAS Concepts Cours : Test Number: 1 Numéro d’examen : Type of Test: Multiple Choice Genre d’examen : Choix multiple Time Allotted: Temps alloué : 45 minutes Answer on the following pages. Répondre sur les feuilles jointes. All test papers must be returned. Remettre le questionnaire à la fin de l’examen. Student Name: ___________________________ Date: ______________________________ Nom de l’étudiant : ________________________ Date : _____________________________ 1. Global Positioning System (GPS) Review Questions Question Answer 1. How many GPS satellites are typically operational in the constellation? a) 24 b) 12-15 c) 26-29 c) 26-29 2. What is the significance of the Satellite PRN? a) PRN is unique to each satellite and identifies the satellite to the receiver b) Identifies satellite launch number c) Identifies GPS constellation a) PRN is unique to each satellite and identifies the satellite to the receiver 3. What are the GPS L1 and L2 frequencies? a) 155.75 and 127.25 MHz b) 1575.42 and 1227.6 MHz c) 3.935 and 6.435 GHz b) 1575.42 and 1227.6 MHz 4. The GPS navigation data message is transmitted on? a) Both L1 and L2 frequencies b) L1 only c) L2 only a) Both L1 and L2 frequencies 5. The minimum L1 C/A code power level received at earth’s surface is? a) > -80 dBmW b) -130 dBmW c) – 100 dBmW b) -130 dBmW 6. The entire Almanac data is transmitted within how many minutes? a) 1 b) 5 c) 12.5 c) 12.5 7. The GPS Monitor and Control stations can take upwards of how many minutes before declaring a satellite unhealthy? a) 45 b) 2 c) 120 a) 45 8. How is a pseudorange to a GPS satellite determined? a) by measuring time b) by measuring distance to the satellite c) by multiplying the signal travel time from the satellite to the receiver times the speed of light c) by multiplying the signal travel time from the satellite to the receiver times the speed of light 9. What is the minimum number of pseudoranges required to compute a three-dimensional position? a) 3 b) 4 c) 6 b) 4 10. Which is a major source of error to the GPS position determination? a) Ionospheric delay b) Receiver noise c) Multipath a) Ionospheric delay 11. Which are the most common sources of RF interference to GPS signals? a) cell phones b) radar or pulsed transmitters c) VHF receivers b) radar or pulsed transmitters 2. Wide-Area Augmentation System (WAAS) Review Questions Question Answer 12. What is the major purpose of WAAS? a) to improve GPS position accuracy and integrity b) to improve flyability c) to provide more visible satellites a) to improve GPS position accuracy and integrity 13. WAAS Reference Stations perform what types of measurements? a) GPS frequencies b) Ionospheric delays c) RF interfering signals b) Ionospheric delays 14. The WAAS GEO satellites perform what functions? a) monitor GPS satellites b) monitor WAAS services c) broadcast WAAS corrections and provide additional ranging source c) broadcast WAAS corrections and provide additional ranging source 15. The WAAS receiver determines from the WAAS messages? a) if a satellite is to be excluded from position calculations b) if all GPS frequencies are serviceable c) full WAAS service volume a) if a satellite is to be excluded from position calculations 16. The WAAS receiver provides continuous integrity monitoring for the user by? a) monitoring WAAS frequencies b) computing the horizontal and vertical protection levels c) accurately computing and displaying the up to date position b) computing the horizontal and vertical protection levels 17. WAAS service is affected by? a) Types of GPS satellites b) Ionospheric corrections and satellite geometry c) Number of users b) Ionospheric corrections and satellite geometry 18. WAAS service volume is limited by? a) frequencies used b) number of reference stations c) GEO satellites visibility c) GEO satellites visibility 19. Which other SBAS are most similar to WAAS? a) Galileo b) EGNOS and MSAS c) GAGAN and Galileo b) EGNOS and MSAS 3. Global Navigation Satellite System (GNSS) Review Questions Question Answer 20. Which GNSS navigation service(s) provide vertical guidance? a) NPA b) LNAV/VNAV and LPV c) ILS b) LNAV/VNAV and LPV 21. Which GNSS service provides the best protection levels with alarm limits of 40m horizontal and 50m vertical? a) LPV b) LNAV c) Terminal a) LPV 22. The probability that the GNSS receiver’s position error exceeds the alert limits without notification to the pilot is? a) 0.999 b) Less than 10-4 c) Less than 10-7 c) Less than 10-7