GLOBAL NAVIGATION SATELLITE SYSTEMS (GNSS) Flashcards
- NAVSTAR/GPS operates in the band the receiver determines position by:
UHF, range position lines
- The NAVSTAR/ GPS control segment comprises:
a master control station, a back-up control station and five monitoring stations
- The orbital height and inclination of the NAVSTAR/GPS constellation are:
20180 km, 55°
- The model of the earth used for NAVSTAR/GPS is:
WGS84
- The minimum number of satellites required for a 3D fix is:
4
- The NAVSTAR/GPS operational constellation comprises how many satellites:
24
- The most accurate fixing information will be obtained from:
one satellite directly overhead and 3 spaced 120° apart close to the horizon
- The most significant error of GNSS is:
ionospheric propagation
- The frequency available to non-authorised users of NAVSTAR/GPS is:
1575.42 MHz
- The purpose of the pseudo-random noise codes in NAVSTAR/GPS is to:
identify the satellites
- The minimum number of satellites required for receiver autonomous integrity monitoring is:
5
- If a receiver has to download the almanac, the time to do this will be:
12.5 minutes
- The use of LAAS and WAAS remove the errors caused by:
elective availability, satellite ephemeris and clock
- The most accurate satellite fixing information will be obtained from:
NAVSTAR/GPS & GLONASS
- A LAAS requires:
an accurately surveyed site on the aerodrome and system known as a pseudolite to pass
corrections to X, Y & Z co-ordinates to aircraft
- The position derived from NAVSTAR/GPS satellites may be subject to the following errors:
propagation, selective availability, ephemeris
- EGNOS is:
a WAAS
- The PRN codes are used to:
determine the time interval between the satellite transmission and receipt of the signal at the receiver
- The availability of two frequencies in GNSS:
reduces propagation errors
- The NAVSTAR/GPS reference system is:
A geo-centred 3D Cartesian co-ordinate system fixed with reference to the prime
meridian, equator and pole
- The initial range calculation at the receiver is known as a pseudo-range, because it is not yet corrected for:
receiver clock errors
- The navigation and system data message is transmitted through the:
50 Hz modulation
- An all in view receiver:
checks all the satellites in view and selects the 4 with the best geometry for fixing
- When using GNSS to carry out a non-precision approach the MDA will be determined using:
barometric altitude
- If an aircraft manoeuvre puts a satellite being used for fixing into the wing shadow then:
the accuracy will be temporarily downgraded
- Which of the following statements concerning NAVSTAR/GPS time is correct?
The satellite runs its own time based on seconds and weeks which is correlated with
UTC