OGRAD 10.03 - GPS Fundamentals

Results

Q1. GPS satellites transmit on two L-band frequencies with different types of signals. Which of these are generally available for use by civil aviation?

L1-coarse acquisition (C/A) with selected availability (S/A)

L2-coarse acquisition (C/A)

L1-precise (P)

L2-selected availability (S/A)

L1-coarse acquisition (C/A) with selected availability (S/A)

Q2. Which of the following coordinate systems is used by the GPS receiver to determine position (Latitude, longitude and altitude)?

EUREF 92

ED 87

ED 50

WGS 84

Q3. Which of the following lists all the parameters that can be determined by a GPS receiver tracking signals from 4 different satellites?

Latitude, longitude and altitude

Latitude and longitude

Latitude, longitude and time

Latitude, longitude, altitude and time

Q4. Which of the following combinations of satellite navigation systems provide the most accurate position fixes in air navigation?

GLONASS and COSPAS-SARSAT

NAVSTAR/GPS and NNSS-Transit

NNSS-Transit and GLONASS

NAVSTAR/GPS and GLONASS

Q5. The required 24 NAVSTAR/GPS operational satellites are located on:

6 orbital planes with 3 satellites in each plane plus 6 reserve satellites positioned in a geostationary orbital plane

3 orbital planes with 8 satellites in each plane

4 orbital planes with 6 satellites in each plane

6 orbital planes with 4 satellites in each plane

Q6. Which of the following statements about the ‘visibility’ of NAVSTAR/GPS satellites is correct?

It is greatest at the poles

It is the same throughout the globe

It is greatest at the equator

It varies, depending on the time and observer's location

It varies, depending on the time and observer’s location

Q7. How many operational satellites are required for Full Operational Capability (FOC) of the satellite navigation system NAVSTAR/GPS?

Q8. Which of the following satellite navigation systems has Full Operational Capability (FOC) and is approved for specified flights under IFR conditions in Europe?

NNSS-Transit

NAVSTAR/GPS

COSPAS-SARSAT

GLONASS

NAVSTAR/GPS

Q9. The distance between a NAVSTAR/GPS satellite and receiver is:

determined by the time taken for the signal to arrive from the satellite multiplied by the speed of light

calculated from the Doppler shift of the known frequencies

calculated, using the WGS-84 reference system, from the known positions of the satellite and the receiver

determined by the phase shift of the Pseudo Random Noise code multiplied by the speed of light

determined by the time taken for the signal to arrive from the satellite multiplied by the speed of light

Q10. In relation to the satellite navigation system NAVSTAR/GPS, ‘All in View’ is a term used when a receiver:

is receiving the signals of all visible satellites but tracking only those of the 4 with the best geometric coverage

is tracking more than the required 4 satellites and can instantly replace any lost signal with another already being monitored

is receiving and tracking the signals of all 24 operational satellites simultaneously

requires the signals of all visible satellites for navigation purposes

is tracking more than the required 4 satellites and can instantly replace any lost signal with another already being monitored

Q11. The reason why the measured distance between a NAVSTAR/GPS satellite navigation system satellite and a receiver is called a ‘Pseudo-Range’ is because the:

measured distance is based on the Pseudo Random Noise code

calculated range includes receiver clock error

movement of satellite and receiver during the distance calculation is not taken into account

calculated range is based on an idealised Keplerian orbit

calculated range includes receiver clock error

Q12. What type of satellite navigation system NAVSTAR/GPS receiver is most suitable for use on board an aircraft?

Sequential

Multichannel

Multiplex

Any hand held type

Multichannel

Q13. What is the minimum number of NAVSTAR/GPS satellites required to produce an accurate independent 3-D position fix?

Q14. The receiver aerial for a NAVSTAR/GPS system should be mounted:

under the fuselage in order to receive correction data transmitted by D-GPS stations

inside the tail fin to minimise the influence of reflections from the wing and fuselage

in the vicinity of the receiver to avoid long transmission lines

on the upper side of the fuselage in the vicinity of the centre of gravity

Q15. In the NAVSTAR/GPS satellite navigation system, ‘Selective Availability’ (SA) is the artificial degradation of the navigation accuracy by:

shutting off selected satellites

dithering the satellite clock

using a less accurate atomic clock in a satellite for signal processing

offsetting satellite atomic clocks by a predetermined constant amount

dithering the satellite clock

Q16. How does ‘Selective Availability’ (SA), if at all, affect the navigation accuracy of the NAVSTAR/GPS satellite navigation system?

It increases because only signals from satellites in the most suitable geometric constellation are selected by the receiver

It degrades position accuracy by manipulating satellite signals

It has no influence because, by selecting of the most suitable signals, the computing process in the receiver is quicker

It degrades accuracy by reducing the number of available satellites

It degrades position accuracy by manipulating satellite signals

Q17. In the NAVSTAR/GPS satellite navigation system, receiver clock error:

is the biggest part of the total error; it cannot be corrected

is corrected by using signals from four satellites

can be minimised by synchronisation of the receiver clock with the satellite clocks

is negligible small because of the great accuracy the atomic clocks installed in the satellites

is corrected by using signals from four satellites

Q18. The navigation accuracy for civil users of the NAVSTAR/GPS satellite navigation system is mainly influenced by:

clock error inside the receiver

receiver noise

the 'Selective Availability' (SA) function

movement of the receiver during the computation process

the ‘Selective Availability’ (SA) function

Q19. The influence of the ionosphere on the accuracy of the satellite navigation system NAVSTAR/GPS is:

only significant if the satellites are located at a small elevation angle above the horizon

minimised by computing the average of all signals

minimised by the receiver using a model of the atmosphere and comparing signals transmitted by the satellites

negligible

minimised by the receiver using a model of the atmosphere and comparing signals transmitted by the satellites

Q20. The basic elements of the satellite navigation system NAVSTAR/GPS are the:

control, space and user segments

main control station, the monitoring station and the ground antennas

antenna, the receiver and the central control unit (CDU)

atomic clock, power supply and transponder

control, space and user segments

Q21. One of the tasks of the control segment of the satellite navigation system NAVSTAR/GPS is to:

manipulate the signals of selected satellites to reduce the precision of the position fix (Selective Availability SA)

manufacture and launch the satellites

monitor the status of the satellites

grant and monitor user authorisations

monitor the status of the satellites

Q22. The main task of the user segment (receiver) of the satellite navigation system NAVSTAR/GPS is to:

select appropriate satellites automatically, to track the signals and to measure the time taken by signals from the satellites to reach the receiver

transmit signals which, from the time taken, are used to determine the distance to the satellite

to monitor the status of the satellites, determine their positions and to measure the time

monitor the orbital planes of the satellites

select appropriate satellites automatically, to track the signals and to measure the time taken by signals from the satellites to reach the receiver

Q23. One of the tasks of the space segment of the satellite navigation system NAVSTAR/GPS is to:

transmit signals which can be used, by suitable receivers, to determine time, position and velocity

transmit signals to suitable receivers and to monitor the orbital planes autonomously

compute the user position from the received user messages and to transmit the computed position back to the user segment

monitor the satellites' orbits and status

transmit signals which can be used, by suitable receivers, to determine time, position and velocity

Q24. The geometric shape of the reference system for the satellite navigation system NAVSTAR/GPS, defined as WGS 84, is:

an ellipsoid (oblate spheroid)

a mathematical model that describes the exact shape of the earth

a sphere

a geoid

an ellipsoid (oblate spheroid)

Q25. In civil aviation, the height value computed by the receiver of the satellite navigation system NAVSTAR/GPS is the:

height above Mean Sea Level (MSL)

geometric height above ground

height above the WGS-84 ellipsoid

flight level

height above the WGS-84 ellipsoid

Q26. In relation to the satellite navigation system NAVSTAR/GPS, the term ‘inclination’ denotes the angle between the:

orbital plane and the equatorial plane

horizontal plane at the location of the receiver and the direct line to a satellite

orbital plane and the earth's axis

horizontal plane at the location of the receiver and the orbital plane of a satellite

orbital plane and the equatorial plane

Q27. How long does it take a NAVSTAR/GPS satellite to orbit the earth?

12 days

Approximately 24 hours (one sidereal day)

Approximately 12 hours (1/2 of a sidereal day)

365 days because the satellites are located in a geostationary orbit

Approximately 12 hours (1/2 of a sidereal day)

Q28. At what approximate height above the WGS-84 ellipsoid are NAVSTAR/GPS satellites circling the earth?

20200 km

10900 km

36000 km

19500 km

20200 km

Q29. The orbital planes of the satellite navigation system NAVSTAR/GPS are:

inclined 55° to the equatorial plane

inclined 55° to the earth axis

inclined 90° to the equatorial plane

parallel to the equatorial plane

inclined 55° to the equatorial plane

Q30. In which frequency bands are the L1 and L2 frequencies used by the satellite navigation system NAVSTAR/GPS for transmission of the navigation message?

EHF

VHF

UHF

SHF

UHF

Q31. In relation to the satellite navigation system NAVSTAR/GPS, which of the following statements correctly describes the term ‘Pseudo Random Noise (PRN)’ signal?

PRN describes the continuous electro-magnetical background noise that exists in space

PRN is the atmospheric jamming that affects the signals transmitted by the satellites

PRN is a code used for the identification of the satellites and the measurement of the time taken by the signal to reach the receiver

PRN occurs in the receiver. It is caused by the signal from one satellite being received from different directions (multipath effect)

PRN is a code used for the identification of the satellites and the measurement of the time taken by the signal to reach the receiver

Q32. Which of the following NAVSTAR/GPS satellite navigation system codes can be processed by ‘unauthorised’ civil aviation receivers?

P and Y

C/A- and P

C/A

Q33. Almanac data stored in the receiver of the satellite navigation system NAVSTAR/GPS is used for the:

recognition of Selective Availability (SA)

fast identification of received signals coming from visible satellites

assignment of received PRN-codes (Pseudo Random Noise) to the appropriate satellite

correction of receiver clock error

fast identification of received signals coming from visible satellites

Q34. How does a NAVSTAR/GPS satellite navigation system receiver recognise which of the received signals belongs to which satellite?

Each satellite transmits its signal on a separate frequency

The Doppler shift is unique to each satellite

The receiver detects the direction from which the signals are received and compares this information with the calculated positions of the satellites

Each satellite transmits its signal, on common frequencies, with an individual Pseudo Random Noise code

Q35. Which of the following data, in addition to the Pseudo Random Noise (PRN) code, forms part of the so called ‘Navigation Message’ transmitted by NAVSTAR/GPS satellites?

time; data to impair the accuracy of the position fix (Selective Availability SA)

almanac data; satellite status information

data to correct receiver clock error; almanac data

time; positions of the satellites

almanac data; satellite status information

Q36. In the NAVSTAR/GPS satellite navigation system, what is the maximum time taken to receive the complete set of almanac data from all satellites?

25 seconds (= 1 second per data frame)

12 hours (= period of the satellites orbit)

12.5 minutes (= 30 seconds per data frame)

24 seconds (= 1 second per data frame)

12.5 minutes (= 30 seconds per data frame)

Q37. Which of the following statements concerning the L1 and L2 NAVSTAR/GPS transmission frequencies and codes is correct?

C/A and P codes are transmitted at different times on both frequencies

The higher frequency is used to transmit both the C/A and P codes

The higher frequency is only used to transmit the P code

The lower frequency is used to transmit both the C/A and P codes

The higher frequency is used to transmit both the C/A and P codes

Q38. Which one of the following errors can be compensated for by a NAVSTAR/GPS receiver comparing L1 and L2 frequencies?

Ionospheric

Multipath

Tropospheric

Receiver noise

Ionospheric

Q39. Which of the following statements is correct concerning the principle behind the correction of one of the NAVSTAR/GPS satellite navigation system errors by the transmission of the signals on two frequencies (L1 and L2)?

The effect of signal reflections (multipath effect) can be reduced due to the interference of both frequencies

The effect of receiver noise can be reduced due to the interference of both frequencies

The path delay of the signals in the earth atmosphere is proportional to the inverse of the carrier frequency squared

The influence of shadowing on the GPS signals is proportional to the inverse of the carrier frequency squared

The path delay of the signals in the earth atmosphere is proportional to the inverse of the carrier frequency squared

Q40. Concerning the NAVSTAR/GPS satellite navigation system, what is the meaning of the term ‘Receiver Autonomous Integrity Monitoring’ (RAIM)?

It is a method whereby a receiver ensures the integrity of the Pseudo Random Noise (PRN) code transmitted by the satellites

It is the ability of the GPS satellites to check the integrity of the data transmitted by the monitoring stations of the ground segment

It is a technique by which a receiver ensures the integrity of the navigation information

It is a technique whereby the receivers of the world-wide distributed monitor stations (ground segment) automatically determines the integrity of the navigation message

It is a technique by which a receiver ensures the integrity of the navigation information

Q41. GPS system satellites transmit their signals on two carrier waves 1575 MHz and 1227 MHz and supply two possible codes accessible acording to user (civil or military). Commercial aviation uses:

only the 1 575 MHz carrier wave and two codes

only the 1 575 MHz carrier wave and one code

only the 1 227 MHz carrier wave and one code

the two carrier waves and one public code

only the 1 575 MHz carrier wave and one code

Q42. Which of the following geometric satellite constellations provides the most accurate NAVSTAR/GPS position fix?

3 satellites with an azimuth of 120° from each other and an elevation of 45° above the horizon

3 satellites with a low elevation above the horizon and an azimuth of 120° from each other together with a fourth directly overhead

4 satellites with an azimuth of 90° from each other and a low elevation above the horizon

4 satellites with an azimuth of 90° from each other and an elevation of 45° above the horizon

3 satellites with a low elevation above the horizon and an azimuth of 120° from each other together with a fourth directly overhead

Q43. How does a receiver of the NAVSTAR/GPS satellite navigation system determine the elevation and azimuth data of a satellite relative to the location of the antenna?

It calculates it by using Almanac data transmitted by the satellites

The data is stored in the receiver together with the Pseudo Random Noise (PRN) code

The data is based on the direction to the satellite determined at the location of the antenna

The data is determined by the satellite and transmitted together with the navigation message

It calculates it by using Almanac data transmitted by the satellites

Q44. In relation to the NAVSTAR/GPS satellite navigation system, ‘Search the Sky’ is a:

continuous process by the ground segment to monitor the GPS satellites

procedure that starts after switching on a receiver if there is no stored satellite data available

procedure performed by the receiver to recognise new satellites becoming operational

continuous procedure performed by the receiver that searches the sky for satellites rising above the horizon

procedure that starts after switching on a receiver if there is no stored satellite data available

Q45. Which of the following procedures must be adopted if, on a flight under IFR conditions using a NAVSTAR/GPS satellite navigation system receiver, the position fix obtained from the GPS receiver differs from the position of conventional navigation systems by an unacceptable amount?

It must be continued under VFR conditions

It may be continued using NAVSTAR/GPS; prior to the next flight all systems must be checked

It may be continued using conventional navigation systems

The pilot must determine the reason for the deviation and correct the error or switch off the faulty system

It may be continued using conventional navigation systems

Q46. What datum is used for the Minimum Descent Altitude (MDA) on a non-precision approach when using the NAVSTAR/GPS satellite navigation system?

If using Differential-GPS (D-GPS) the altitude obtained from the D-GPS, otherwise barometric altitude

Barometric altitude

Radar altitude

GPS altitude

Barometric altitude

Q47. Which of the following is the datum for altitude information when conducting flights under IFR conditions on airways using the NAVSTAR/GPS satellite navigation system?

GPS altitude if 4 or more satellites are received otherwise barometric altitude

The average of GPS altitude and barometric altitude

GPS altitude

Barometric altitude

Q48. The satellites used in the GPS

Are geostationary

Do not cross the plane of the Equator

All have different planes of orbit

Orbit the Earth at an altitude of about 20 200 km

Q49. Using GPS, the primary position information is in the form of

Spheres, with the satellites in the centre of the spheres

Spheres, with the airplane in the centre of the spheres

Bearing and distance from the satellite

3-dimensional position, with the Earth's centre as reference

Spheres, with the satellites in the centre of the spheres

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Results

Q1. GPS satellites transmit on two L-band frequencies with different types of signals. Which of these are generally available for use by civil aviation?

Q2. Which of the following coordinate systems is used by the GPS receiver to determine position (Latitude, longitude and altitude)?

Q3. Which of the following lists all the parameters that can be determined by a GPS receiver tracking signals from 4 different satellites?

Q4. Which of the following combinations of satellite navigation systems provide the most accurate position fixes in air navigation?

Q5. The required 24 NAVSTAR/GPS operational satellites are located on:

Q6. Which of the following statements about the ‘visibility’ of NAVSTAR/GPS satellites is correct?

Q7. How many operational satellites are required for Full Operational Capability (FOC) of the satellite navigation system NAVSTAR/GPS?

Q8. Which of the following satellite navigation systems has Full Operational Capability (FOC) and is approved for specified flights under IFR conditions in Europe?

Q9. The distance between a NAVSTAR/GPS satellite and receiver is:

Q10. In relation to the satellite navigation system NAVSTAR/GPS, ‘All in View’ is a term used when a receiver:

Q11. The reason why the measured distance between a NAVSTAR/GPS satellite navigation system satellite and a receiver is called a ‘Pseudo-Range’ is because the:

Q12. What type of satellite navigation system NAVSTAR/GPS receiver is most suitable for use on board an aircraft?

Q13. What is the minimum number of NAVSTAR/GPS satellites required to produce an accurate independent 3-D position fix?

Q14. The receiver aerial for a NAVSTAR/GPS system should be mounted:

Q15. In the NAVSTAR/GPS satellite navigation system, ‘Selective Availability’ (SA) is the artificial degradation of the navigation accuracy by:

Q16. How does ‘Selective Availability’ (SA), if at all, affect the navigation accuracy of the NAVSTAR/GPS satellite navigation system?

Q17. In the NAVSTAR/GPS satellite navigation system, receiver clock error:

Q18. The navigation accuracy for civil users of the NAVSTAR/GPS satellite navigation system is mainly influenced by:

Q19. The influence of the ionosphere on the accuracy of the satellite navigation system NAVSTAR/GPS is:

Q20. The basic elements of the satellite navigation system NAVSTAR/GPS are the:

Q21. One of the tasks of the control segment of the satellite navigation system NAVSTAR/GPS is to:

Q22. The main task of the user segment (receiver) of the satellite navigation system NAVSTAR/GPS is to:

Q23. One of the tasks of the space segment of the satellite navigation system NAVSTAR/GPS is to:

Q24. The geometric shape of the reference system for the satellite navigation system NAVSTAR/GPS, defined as WGS 84, is:

Q25. In civil aviation, the height value computed by the receiver of the satellite navigation system NAVSTAR/GPS is the:

Q26. In relation to the satellite navigation system NAVSTAR/GPS, the term ‘inclination’ denotes the angle between the:

Q27. How long does it take a NAVSTAR/GPS satellite to orbit the earth?

Q28. At what approximate height above the WGS-84 ellipsoid are NAVSTAR/GPS satellites circling the earth?

Q29. The orbital planes of the satellite navigation system NAVSTAR/GPS are:

Q30. In which frequency bands are the L1 and L2 frequencies used by the satellite navigation system NAVSTAR/GPS for transmission of the navigation message?

Q31. In relation to the satellite navigation system NAVSTAR/GPS, which of the following statements correctly describes the term ‘Pseudo Random Noise (PRN)’ signal?

Q32. Which of the following NAVSTAR/GPS satellite navigation system codes can be processed by ‘unauthorised’ civil aviation receivers?

Q33. Almanac data stored in the receiver of the satellite navigation system NAVSTAR/GPS is used for the:

Q34. How does a NAVSTAR/GPS satellite navigation system receiver recognise which of the received signals belongs to which satellite?

Q35. Which of the following data, in addition to the Pseudo Random Noise (PRN) code, forms part of the so called ‘Navigation Message’ transmitted by NAVSTAR/GPS satellites?

Q36. In the NAVSTAR/GPS satellite navigation system, what is the maximum time taken to receive the complete set of almanac data from all satellites?

Q37. Which of the following statements concerning the L1 and L2 NAVSTAR/GPS transmission frequencies and codes is correct?

Q38. Which one of the following errors can be compensated for by a NAVSTAR/GPS receiver comparing L1 and L2 frequencies?

Q39. Which of the following statements is correct concerning the principle behind the correction of one of the NAVSTAR/GPS satellite navigation system errors by the transmission of the signals on two frequencies (L1 and L2)?

Q40. Concerning the NAVSTAR/GPS satellite navigation system, what is the meaning of the term ‘Receiver Autonomous Integrity Monitoring’ (RAIM)?

Q41. GPS system satellites transmit their signals on two carrier waves 1575 MHz and 1227 MHz and supply two possible codes accessible acording to user (civil or military). Commercial aviation uses:

Q42. Which of the following geometric satellite constellations provides the most accurate NAVSTAR/GPS position fix?

Q43. How does a receiver of the NAVSTAR/GPS satellite navigation system determine the elevation and azimuth data of a satellite relative to the location of the antenna?

Q44. In relation to the NAVSTAR/GPS satellite navigation system, ‘Search the Sky’ is a:

Q45. Which of the following procedures must be adopted if, on a flight under IFR conditions using a NAVSTAR/GPS satellite navigation system receiver, the position fix obtained from the GPS receiver differs from the position of conventional navigation systems by an unacceptable amount?

Q46. What datum is used for the Minimum Descent Altitude (MDA) on a non-precision approach when using the NAVSTAR/GPS satellite navigation system?

Q47. Which of the following is the datum for altitude information when conducting flights under IFR conditions on airways using the NAVSTAR/GPS satellite navigation system?

Q48. The satellites used in the GPS

Q49. Using GPS, the primary position information is in the form of

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