How Satellite Navigation Finds Your Position: Reading Answers & Explanations
IELTS Reading practice test · 14 questionsAcademicmedium
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About this passage
The passage opens: “Not long ago, finding the way across an unfamiliar city meant unfolding a paper map on the passenger seat and hoping for the best. Today a small device in almost every pocket can announce a person's position to within a few metres, anywhere on the surface of the Earth, by day or night and in almost any weather.”
- Passage length: about 744 words
- Questions: 14
- Question types: Matching Information, Summary Completion, Short Answer
“How Satellite Navigation Finds Your Position” is an original IELTS-style practice passage written by IELTS-Bank. It is not taken from an official IELTS or Cambridge test, so these answers only apply to our version.
Answer key at a glance
How Satellite Navigation Finds Your Position answers with explanations
Questions 1–6: Matching Information
The passage has seven paragraphs, A-G. Which paragraph contains the following information? Write the correct letter, A-G. You may use any letter more than once.
- A. Paragraph A
- B. Paragraph B
- C. Paragraph C
- D. Paragraph D
- E. Paragraph E
- F. Paragraph F
- G. Paragraph G
- 1
an explanation of why a fourth satellite, rather than three, is required
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Answer: Paragraph D
Why: This is the part of the passage that supports Paragraph D.
Evidence · Paragraph D “By taking a fourth measurement, the receiver gains just enough extra information to solve for its own clock error as well as its position”
- 2
a description of the everyday accuracy of a modern positioning device
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Answer: Paragraph A
Why: This is the part of the passage that supports Paragraph A.
Evidence · Paragraph A “…a small device in almost every pocket can announce a person's position to within a few metres”
- 3
an account of how atmospheric conditions reduce accuracy
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Answer: Paragraph F
Why: This is the part of the passage that supports Paragraph F.
Evidence · Paragraph F “As the signals pass through the upper atmosphere they are slowed by a small and variable amount, introducing an error that must be estimated and removed.”
- 4
the three items of information contained in a satellite's signal
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Answer: Paragraph B
Why: This is the part of the passage that supports Paragraph B.
Evidence · Paragraph B “…that signal carries three pieces of information: which satellite is sending it, exactly where that satellite is at the moment of sending, and the precise instant at which the signal left.”
- 5
a reference to the effects predicted by Einstein
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Answer: Paragraph E
Why: This is the part of the passage that supports Paragraph E.
Evidence · Paragraph E “…the engineers must allow for the predictions of Einstein's theories, since a clock in orbit runs at a very slightly different rate from one on the ground”
- 6
the name given to fixing a position from several known distances
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Answer: Paragraph C
Why: This is the part of the passage that supports Paragraph C.
Evidence · Paragraph C “This method of pinning down a position from several known distances is called trilateration”
Questions 7–10: Summary Completion
Complete the summary below.
Complete the summary using NO MORE THAN TWO WORDS from the passage for each answer. A receiver works out where it is by measuring the tiny interval of (7) ______ that a satellite's signal takes to arrive. Multiplying this by the speed of light gives the (8) ______ from that satellite. A fourth satellite is needed so that the receiver can correct the error in its own (9) ______ . Because timing must be so exact, each satellite carries an (10) ______ clock.
- 7
A receiver works out where it is by measuring the tiny interval of ______ that a satellite's signal takes to arrive.(max 2 words)
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Answer: time (also accepted: interval)
Why: The answer “time” is taken from this sentence — copy the word(s) exactly as they appear. It fits the 2-word limit.
Evidence · Paragraph C “…the receiver can multiply that speed by the tiny interval the signal took to arrive”
- 8
Multiplying this by the speed of light gives the ______ from that satellite.(max 2 words)
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Answer: distance
Why: The answer “distance” is taken from this sentence — copy the word(s) exactly as they appear. It fits the 2-word limit.
Evidence · Paragraph C “…and so calculate its distance from that particular satellite.”
- 9
A fourth satellite is needed so that the receiver can correct the error in its own ______ .(max 2 words)
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Answer: clock (also accepted: clock error)
Why: The answer “clock” is taken from this sentence — copy the word(s) exactly as they appear. It fits the 2-word limit.
Evidence · Paragraph D “…the receiver gains just enough extra information to solve for its own clock error as well as its position”
- 10
Because timing must be so exact, each satellite carries an ______ clock.(max 2 words)
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Answer: atomic
Why: The answer “atomic” is taken from this sentence — copy the word(s) exactly as they appear. It fits the 2-word limit.
Evidence · Paragraph E “…each satellite carries an atomic clock”
Questions 11–14: Short Answer
Answer the questions below. Choose NO MORE THAN THREE WORDS AND/OR A NUMBER from the passage for each answer.
- 11
Roughly how high above the Earth do the navigation satellites orbit?(max 3 words)
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Answer: twenty thousand kilometres (also accepted: 20000 kilometres / twenty thousand km)
Why: The answer “twenty thousand kilometres” is taken from this sentence — copy the word(s) exactly as they appear. It fits the 3-word limit.
Evidence · Paragraph B “…that orbit the Earth at a height of roughly twenty thousand kilometres.”
- 12
What is the method of fixing a location from several known distances called?(max 3 words)
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Answer: trilateration
Why: The answer “trilateration” is taken from this sentence — copy the word(s) exactly as they appear. It fits the 3-word limit.
Evidence · Paragraph C “This method of pinning down a position from several known distances is called trilateration”
- 13
What kind of clock does each satellite carry?(max 3 words)
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Answer: an atomic clock (also accepted: atomic clock)
Why: The answer “an atomic clock” is taken from this sentence — copy the word(s) exactly as they appear. It fits the 3-word limit.
Evidence · Paragraph E “…each satellite carries an atomic clock, a device so stable that it would lose or gain no more than a second over many thousands of years.”
- 14
In cities, what do the signals bounce off, confusing the measurement?(max 3 words)
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Answer: tall glass buildings (also accepted: glass buildings / buildings)
Why: The answer “tall glass buildings” is taken from this sentence — copy the word(s) exactly as they appear. It fits the 3-word limit.
Evidence · Paragraph F “In cities the signals bounce off tall glass buildings and reach the receiver by more than one path”
Estimated band score for this test
Your raw score out of 14 scaled to the 40-question IELTS Reading (Academic) conversion table. This is the same estimate the practice page shows after you submit. A single passage is a small sample, so treat it as a guide.
| Correct answers | Estimated band |
|---|---|
| 14 / 14 | 9.0 |
| 13 / 14 | 8.5 |
| 12 / 14 | 7.5 |
| 11 / 14 | 7.0 |
| 10 / 14 | 6.5 |
| 8–9 / 14 | 6.0 |
| 7 / 14 | 5.5 |
| 6 / 14 | 5.0 |
| 5 / 14 | 4.5 |
| 4 / 14 | 4.0 |
| 3 / 14 | 3.5 |
| 2 / 14 | 3.0 |
| 1 / 14 | 2.0 |
| 0 / 14 | 0.0 |
Full-test score? Use the IELTS band calculator.
Tips for the question types in this test
Matching Information
- Read each statement and identify exactly what kind of information you are looking for — a reason, a result, an example, a definition, a contrast.
- Note that the statements do NOT follow paragraph order, so treat each one as an independent search.
Common trap: Assuming the questions run in order — they do not, which makes linear reading inefficient.
Full Matching Information strategySummary Completion
- Read the full summary first and identify which passage section it covers.
- Predict the grammar and meaning required in every blank.
Common trap: Choosing an option only because it repeats a passage word.
Full Summary Completion strategyShort Answer
- Read the instructions and note the exact word limit; going over it means zero marks even if the meaning is right.
- Turn each question into a set of keywords and predict what kind of answer it needs (a person, a date, a place, a noun).
Common trap: Exceeding the word limit (writing four words when only three are allowed).
Full Short Answer strategyPractise “How Satellite Navigation Finds Your Position” under exam conditions
Free, auto-marked, with the 20-minute timer and an instant band estimate.
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