- •Textbook Series
- •Contents
- •1 Properties of Radio Waves
- •Introduction
- •The Radio Navigation Syllabus
- •Electromagnetic (EM) Radiation
- •Polarization
- •Radio Waves
- •Wavelength
- •Frequency Bands
- •Phase Comparison
- •Practice Frequency (
- •Answers to Practice Frequency (
- •Questions
- •Answers
- •2 Radio Propagation Theory
- •Introduction
- •Factors Affecting Propagation
- •Propagation Paths
- •Non-ionospheric Propagation
- •Ionospheric Propagation
- •Sky Wave
- •HF Communications
- •Propagation Summary
- •Super-refraction
- •Sub-refraction
- •Questions
- •Answers
- •3 Modulation
- •Introduction
- •Keyed Modulation
- •Amplitude Modulation (AM)
- •Single Sideband (SSB)
- •Frequency Modulation (FM)
- •Phase Modulation
- •Pulse Modulation
- •Emission Designators
- •Questions
- •Answers
- •4 Antennae
- •Introduction
- •Basic Principles
- •Aerial Feeders
- •Polar Diagrams
- •Directivity
- •Radar Aerials
- •Modern Radar Antennae
- •Questions
- •Answers
- •5 Doppler Radar Systems
- •Introduction
- •The Doppler Principle
- •Airborne Doppler
- •Janus Array System
- •Doppler Operation
- •Doppler Navigation Systems
- •Questions
- •Answers
- •6 VHF Direction Finder (VDF)
- •Introduction
- •Procedures
- •Principle of Operation
- •Range of VDF
- •Factors Affecting Accuracy
- •Determination of Position
- •VDF Summary
- •Questions
- •Answers
- •7 Automatic Direction Finder (ADF)
- •Introduction
- •Non-directional Beacon (NDB)
- •Principle of Operation
- •Frequencies and Types of NDB
- •Aircraft Equipment
- •Emission Characteristics and Beat Frequency Oscillator (BFO)
- •Presentation of Information
- •Uses of the Non-directional Beacon
- •Plotting ADF Bearings
- •Track Maintenance Using the RBI
- •Homing
- •Tracking Inbound
- •Tracking Outbound
- •Drift Assessment and Regaining Inbound Track
- •Drift Assessment and Outbound Track Maintenance
- •Holding
- •Runway Instrument Approach Procedures
- •Factors Affecting ADF Accuracy
- •Factors Affecting ADF Range
- •Accuracy
- •ADF Summary
- •Questions
- •Answers
- •8 VHF Omni-directional Range (VOR)
- •Introduction
- •The Principle of Operation
- •Terminology
- •Transmission Details
- •Identification
- •Monitoring
- •Types of VOR
- •The Factors Affecting Operational Range of VOR
- •Factors Affecting VOR Beacon Accuracy
- •The Cone of Ambiguity
- •Doppler VOR (DVOR)
- •VOR Airborne Equipment
- •VOR Deviation Indicator
- •Radio Magnetic Indicator (RMI)
- •Questions
- •In-flight Procedures
- •VOR Summary
- •Questions
- •Annex A
- •Annex B
- •Annex C
- •Answers
- •Answers to Page 128
- •9 Instrument Landing System (ILS)
- •Introduction
- •ILS Components
- •ILS Frequencies
- •DME Paired with ILS Channels
- •ILS Identification
- •Marker Beacons
- •Ground Monitoring of ILS Transmissions
- •ILS Coverage
- •ILS Principle of Operation
- •ILS Presentation and Interpretation
- •ILS Categories (ICAO)
- •Errors and Accuracy
- •Factors Affecting Range and Accuracy
- •ILS Approach Chart
- •ILS Calculations
- •ILS Summary
- •Questions
- •Answers
- •10 Microwave Landing System (MLS)
- •Introduction
- •ILS Disadvantages
- •The MLS System
- •Principle of Operation
- •Airborne Equipment
- •Question
- •Answer
- •11 Radar Principles
- •Introduction
- •Types of Pulsed Radars
- •Radar Applications
- •Radar Frequencies
- •Pulse Technique
- •Theoretical Maximum Range
- •Primary Radars
- •The Range of Primary Radar
- •Radar Measurements
- •Radar Resolution
- •Moving Target Indication (MTI)
- •Radar Antennae
- •Questions
- •Answers
- •12 Ground Radar
- •Introduction
- •Area Surveillance Radars (ASR)
- •Terminal Surveillance Area Radars
- •Aerodrome Surveillance Approach Radars
- •Airport Surface Movement Radar (ASMR)
- •Questions
- •Answers
- •13 Airborne Weather Radar
- •Introduction
- •Component Parts
- •AWR Functions
- •Principle of Operation
- •Weather Depiction
- •Control Unit
- •Function Switch
- •Mapping Operation
- •Pre-flight Checks
- •Weather Operation
- •Colour AWR Controls
- •AWR Summary
- •Questions
- •Answers
- •14 Secondary Surveillance Radar (SSR)
- •Introduction
- •Advantages of SSR
- •SSR Display
- •SSR Frequencies and Transmissions
- •Modes
- •Mode C
- •SSR Operating Procedure
- •Special Codes
- •Disadvantages of SSR
- •Mode S
- •Pulses
- •Benefits of Mode S
- •Communication Protocols
- •Levels of Mode S Transponders
- •Downlink Aircraft Parameters (DAPS)
- •Future Expansion of Mode S Surveillance Services
- •SSR Summary
- •Questions
- •Answers
- •15 Distance Measuring Equipment (DME)
- •Introduction
- •Frequencies
- •Uses of DME
- •Principle of Operation
- •Twin Pulses
- •Range Search
- •Beacon Saturation
- •Station Identification
- •VOR/DME Frequency Pairing
- •DME Range Measurement for ILS
- •Range and Coverage
- •Accuracy
- •DME Summary
- •Questions
- •Answers
- •16 Area Navigation Systems (RNAV)
- •Introduction
- •Benefits of RNAV
- •Types and Levels of RNAV
- •A Simple 2D RNAV System
- •Operation of a Simple 2D RNAV System
- •Principle of Operation of a Simple 2D RNAV System
- •Limitations and Accuracy of Simple RNAV Systems
- •Level 4 RNAV Systems
- •Requirements for a 4D RNAV System
- •Control and Display Unit (CDU)
- •Climb
- •Cruise
- •Descent
- •Kalman Filtering
- •Questions
- •Appendix A
- •Answers
- •17 Electronic Flight Information System (EFIS)
- •Introduction
- •EHSI Controller
- •Full Rose VOR Mode
- •Expanded ILS Mode
- •Full Rose ILS Mode
- •Map Mode
- •Plan Mode
- •EHSI Colour Coding
- •EHSI Symbology
- •Questions
- •Appendix A
- •Answers
- •18 Global Navigation Satellite System (GNSS)
- •Introduction
- •Satellite Orbits
- •Position Reference System
- •The GPS Segments
- •The Space Segment
- •The Control Segment
- •The User Segment
- •Principle Of Operation
- •GPS Errors
- •System Accuracy
- •Integrity Monitoring
- •Differential GPS (DGPS)
- •Combined GPS and GLONASS Systems
- •Questions
- •Answers
- •19 Revision Questions
- •Questions
- •Answers
- •Specimen Examination Paper
- •Appendix A
- •Answers to Specimen Examination Paper
- •Explanation of Selected Questions
- •20 Index
18 Global Navigation Satellite Systems (GNSS)
Combined GPS and GLONASS Systems
Receiver systems combining GPS and GLONASS are under development. The ability to combine positional information from the two systems will provide improved accuracy and enhanced integrity monitoring. However, since the SV systems use different models of the earth, the GLONASS PZ90 generated information will need to be converted to the GPS WGS84 model, or vice versa, to provide the final position.
(GNSS) Systems Satellite Navigation Global 18
322
Questions 18
Questions
1.NAVSTAR/GPS operates in the ....... band the receiver determines position by .......:
a. |
UHF |
range position lines |
b. |
UHF |
secondary radar principles |
c. |
SHF |
secondary radar principles |
d. |
SHF |
range position lines |
2.The NAVSTAR/ GPS control segment comprises:
a.the space segment, the user segment and the ground segment
b.a ground segment and the INMARSAT geostationary satellites
c.a master control station, a back-up control station and five monitoring stations
d.a master control station, a back-up control station, five monitoring stations and the INMARSAT geostationary satellites
3.The orbital height and inclination of the NAVSTAR/GPS constellation are:
a.20 180 km, 65°
b.20 180 km, 55°
c.19 099 km, 65°
d.19 099 km, 55°
4.The model of the earth used for NAVSTAR/GPS is:
a.WGS90
b.PZ90
c.WGS84
d.PZ84
5.The minimum number of satellites required for a 3D fix is:
a.3
b.4
c.5
d.6
6.The NAVSTAR/GPS operational constellation comprises how many satellites?
a.12
b.21
c.24
d.30
7.The most accurate fixing information will be obtained from:
a.four satellites spaced 90° apart at 30° above the visual horizon
b.one satellite close to the horizon and 3 equally at 60° above the horizon
c.one satellite directly overhead and 3 equally spaced at 60° above the horizon
d.one satellite directly overhead and 3 spaced 120° apart close to the horizon
Questions 18
323
18 Questions
8. |
The most significant error of GNSS is: |
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a. |
PDOP |
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b. |
receiver clock |
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c. |
ionospheric propagation |
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d. |
ephemeris |
9. |
The frequency available to non-authorized users of NAVSTAR/GPS is: |
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a. |
1227.6 MHz |
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b. |
1575.42 MHz |
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c. |
1602 MHz |
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d. |
1246 MHz |
10. |
The purpose of the pseudo-random noise codes in NAVSTAR/GPS is to: |
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a. |
identify the satellites |
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b. |
pass the almanac data |
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c. |
pass the navigation and system data |
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d. |
pass the ephemeris and time information |
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11. |
The |
minimum number of satellites required for receiver autonomous integrity |
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monitoring is: |
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a. |
3 |
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b. |
4 |
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c. |
5 |
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d. |
6 |
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12. |
If a receiver has to download the almanac, the time to do this will be: |
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a. |
2.5 minutes |
18 |
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b. |
12.5 minutes |
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c. |
25 minutes |
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Questions |
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d. |
15 minutes |
13. |
The use of LAAS and WAAS remove the errors caused by: |
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a. |
propagation, selective availability, satellite ephemeris and clock |
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b. |
selective availability, satellite ephemeris and clock |
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c. |
PDOP, selective availability and propagation |
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d. |
receiver clock, PDOP, satellite ephemeris and clock |
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14. |
The most accurate satellite fixing information will be obtained from: |
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a. |
NAVSTAR/GPS & GLONASS |
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b. |
TRANSIT & NAVSTAR/GPS |
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c. |
COSPAS/SARSAT & GLONASS |
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d. |
NAVSTAR/GPS & COSPAS/SARSAT |
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Questions |
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18 |
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15. |
A LAAS requires: |
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a. |
an accurately surveyed site on the aerodrome and a link through the INMARSAT |
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geostationary satellites to pass corrections to X, Y & Z coordinates to aircraft |
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b. |
an accurately surveyed site on the aerodrome and a link through the INMARSAT |
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geostationary satellites to pass satellite range corrections to aircraft |
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c. |
an accurately surveyed site on the aerodrome and a system known as a |
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pseudolite to pass satellite range corrections to aircraft |
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d. |
an accurately surveyed site on the aerodrome and system known as a pseudolite |
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to pass corrections to X, Y & Z coordinates to aircraft |
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16. |
The position derived from NAVSTAR/GPS satellites may be subject to the following |
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errors: |
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a. |
selective availability, sky wave interference, PDOP |
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b. |
propagation, selective availability, ephemeris |
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c. |
PDOP, static interference, instrument |
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d. |
ephemeris, PDOP, siting |
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17. |
EGNOS is: |
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a. |
the proposed European satellite navigation system |
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b. |
a LAAS |
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c. |
a WAAS |
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d. |
a system to remove errors caused by the difference between the model of the |
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earth and the actual shape of the earth |
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18. |
The PRN codes are used to: |
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a. |
determine the time interval between the satellite transmission and receipt of |
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the signal at the receiver |
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b. |
pass ephemeris and clock data to the receivers |
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c. |
synchronize the receiver clocks with the satellites clocks |
18 |
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d. |
determine the range of the satellites from the receiver |
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Questions |
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19. |
The availability of two frequencies in GNSS: |
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a. |
removes SV ephemeris and clock errors |
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b. |
reduces propagation errors |
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c. |
reduces errors caused by PDOP |
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d. |
removes receiver clock errors |
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20. |
The NAVSTAR/GPS reference system is: |
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a. |
A geo-centred 3D Cartesian coordinate system fixed with reference to the sun |
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b. |
A geo-centred 3D Cartesian coordinate system fixed with reference to the |
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prime meridian, equator and pole |
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c. |
A geo-centred 3D Cartesian coordinate system fixed with reference to space |
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d. |
A geo-centred 3D system based on latitude, longitude and altitude |
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325
18 Questions
21. |
The initial range calculation at the receiver is known as a pseudo-range, because it |
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is not yet corrected for: |
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a. |
receiver clock errors |
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b. |
receiver and satellite clock errors |
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c. |
receiver and satellite clock errors and propagation errors |
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d. |
receiver and satellite clock errors and ephemeris errors |
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22. |
The navigation and system data message is transmitted through the: |
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a. |
50 Hz modulation |
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b. |
the C/A and P PRN codes |
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c. |
the C/A code |
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d. |
the P code |
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23. |
An all in view receiver: |
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a. |
informs the operator that all the satellites required for fixing and RAIM are in |
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available |
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b. |
checks all the satellites in view and selects the 4 with the best geometry for |
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fixing |
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c. |
requires 5 satellites to produce a 4D fix |
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d. |
uses all the satellites in view for fixing |
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24. |
When using GNSS to carry out a non-precision approach the MDA will be determined |
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using: |
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a. |
barometric altitude |
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b. |
GPS altitude |
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c. |
radio altimeter height |
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d. |
either barometric or radio altimeter altitude |
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25. |
If an aircraft manoeuvre puts a satellite being used for fixing into the wing shadow |
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18 |
then: |
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Questions |
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a. |
the accuracy will be unaffected |
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b. |
the accuracy will be temporarily downgraded |
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c. |
the receiver will automatically select another satellite with no degradation in |
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positional accuracy |
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d. |
the receiver will maintain lock using signals reflected from other parts of the |
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aircraft with a small degrading of positional accuracy |
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26. |
Which of the following statements concerning NAVSTAR/GPS time is correct? |
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a. |
Satellite time is the same as UTC |
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b. |
The satellite runs its own time based on seconds and weeks which is |
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independent of UTC |
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c. |
The satellite runs its own time based on seconds and weeks which is correlated |
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with UTC |
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d. |
Satellite time is based on sidereal time |
326
Questions 18
Questions 18
327