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Global Navigation Satellite Systems
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Global Navigation Satellite Systems
Global Navigation Satellite Systems
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1
Question
Which term denotes satellite navigation systems that provide autonomous geospatial positioning with global coverage?
Page 2
Answer
Global Navigation Satellite Systems (GNSS).
2
Question
What type of data do GNSS satellites transmit from space?
Page 2
Answer
Positioning and timing data.
3
Question
Which three segments make up a GNSS?
Page 2
Answer
Space, control, and user segments.
4
Question
Which GNSS segment consists of satellites orbiting Earth?
Page 3
Answer
The space segment.
5
Question
Which GNSS segment tracks and monitors the satellites?
Page 3
Answer
The control segment.
6
Question
What does the user segment compute using satellite signals?
Page 3
Answer
The user’s position and motion.
7
Question
Which segment contains the GNSS satellites?
Page 4
Answer
The space segment.
8
Question
Which segment includes data uploading, the master control station, and base stations?
Page 4
Answer
The control segment.
9
Question
Which segment includes vehicle, surveying, and unmanned-aircraft receivers?
Page 4
Answer
The user segment.
10
Question
Which organization operates the Global Positioning System (GPS)?
Page 5
Answer
The United States Department of Defense (DoD).
11
Question
How many satellites and orbital planes support the GPS constellation?
Page 5
Answer
24 to 32 satellites across 6 orbital planes.
12
Question
At approximately what altitude does GPS orbit above Earth?
Page 5
Answer
22,000 km above Earth.
13
Question
Which two services does GPS provide?
Page 5
Answer
Precise Positioning Service (PPS) and Standard Positioning Service (SPS).
14
Question
Who is authorized to use the Precise Positioning Service (PPS)?
Page 6
Answer
The Department of Defense and authorized partners.
15
Question
Who can use the Standard Positioning Service (SPS)?
Page 6
Answer
Worldwide civilian users.
16
Question
What was the purpose of selective availability in civilian GPS?
Page 6
Answer
To degrade the accuracy of the Standard Positioning Service.
17
Question
When was selective availability permanently stopped?
Page 6
Answer
May 2000.
18
Question
Which organization operates GLONASS?
Page 8
Answer
The Russian Aerospace Defense Forces.
19
Question
How are GLONASS satellites arranged in orbit?
Page 8
Answer
24 satellites distributed across 3 orbital planes.
20
Question
Why does GLONASS provide an advantage at higher latitudes?
Page 8
Answer
It provides better coverage at higher latitudes than other GNSS.
21
Question
Which GNSS is sometimes called COMPASS and includes regional and global satellites?
Page 10
Answer
BeiDou.
22
Question
Which organization operates BeiDou?
Page 10
Answer
The China National Space Administration.
23
Question
What was the intended service area of the BeiDou Navigation Demonstration System (BDS-1)?
Page 10
Answer
The whole country of China.
24
Question
What regional area was targeted by the BeiDou Navigation Satellite System (BDS-2)?
Page 10
Answer
The Asia-Pacific region.
25
Question
Complete the statement: The third development step was to _____ BDS and provide services around 2020.
Page 11
Answer
complete
26
Question
When was the last BeiDou satellite launched?
Page 11
Answer
23 June 2020.
27
Question
How many BeiDou satellites had been launched into orbit according to the lecture?
Page 11
Answer
55 satellites.
28
Question
Which services does the completed BeiDou constellation provide to global users?
Page 11
Answer
Continuous, stable, reliable positioning, navigation, and timing services.
29
Question
How does a GNSS receiver calculate its location on Earth?
Page 17
Answer
It compares each satellite’s known orbital position with the time required to receive its signal, then uses these measurements to calculate its location.
30
Question
Which measurement distinguishes trilateration from triangulation?
Page 19
Answer
Trilateration measures distances, whereas triangulation measures angles.