UPSC Prelims 2018 · Question 61 of 99

UPSC Prelims 2018 question on IRNSS Navic Satellites

With reference to the Indian Regional Navigation Satellite System (IRNSS), consider the following statements:

1. IRNSS has three satellites in geostationary and four satellites in geosynchronous orbits.

2. IRNSS covers entire India and about 5500 sq. km beyond its borders.

3. India will have its own satellite navigation system with full global coverage by the middle of 2019.

Which of the statements given above is/are correct?

  1. 1 only
  2. 1 and 2 only
  3. 2 and 3 only
  4. None
Show answer

Answer: A. 1 only

Verdict

Only statement 1 is correct, so the answer is (a) 1 only.

Statement by statement

Statement 1 is CORRECT. The IRNSS space segment is a constellation of seven satellites, called NavIC. Three sit in geostationary orbital slots and the remaining four in geosynchronous orbits with the required inclination and equatorial crossings in two different planes.

Statement 2 is INCORRECT. IRNSS is designed to serve users in India and the region extending up to 1500 km from its boundary, which is its primary service area, with an extended service area beyond that. The figure of 5500 square kilometres both misstates the distance and uses the wrong unit for it.

Statement 3 is INCORRECT. IRNSS is a regional system, and India will not have a satellite navigation system with full global coverage by the middle of 2019.

Source

ISRO IRNSS programme page, and The Hindu report on IRNSS-1I completing the navigation fleet.

How to crack it

Read the unit, not just the number. Statement 2 offers an area in square kilometres where coverage beyond a border must be a distance, and 5500 square kilometres would be a trivially small patch. Unit mismatch is a quiet but reliable tell. The name itself, Indian Regional Navigation Satellite System, disposes of statement 3.

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