Why does the NISAR mission schedule repeated observations of the same region every 12 days?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. To obtain regular imaging that helps track global changes and surface deformation.
The NISAR mission revisits the same region every 12 days to obtain regular, high-precision imaging for monitoring global changes and surface deformation. This consistent temporal resolution is essential for studying earthquakes, landslides, glacier movements, agricultural patterns, and ecosystem shifts. Since NISAR uses advanced L-band and S-band synthetic aperture radars, frequent observations help detect even centimeter-level ground displacement.
Other options are not accurate:
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Maintaining satellite stability is managed by onboard navigation systems, not revisit cycles.
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Reducing fuel usage is not the primary reason; NISAR follows a pre-set sun-synchronous orbit.
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Storing data longer before transmission is unnecessary because the mission uses regular downlink windows to relay data efficiently.