Advantages of satellite-platform Earth observation Select the comprehensive statement about what Earth observation from satellites provides to users and analysts.
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Asynoptic view of a large area
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Bconstant solar zenith angles and similar illumination conditions.
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Crepetitive observations of the same area with intervals of a few minutes to a few weeks
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DAll of these
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ENone of these
Answer
Correct Answer: All of these
Explanation
Introduction / Context:Satellite platforms revolutionised Earth observation by enabling consistent, repeatable, and wide-area measurements. Mission design—orbit type, revisit cycle, swath—determines coverage, temporal sampling, and illumination conditions for change detection and mapping.
Given Data / Assumptions:
- Polar sun-synchronous orbits yield near-constant local solar time passes.
- Geostationary orbits provide high-frequency sampling for weather.
- Revisit can range from minutes (GEO) to days/weeks (LEO constellations).
Concept / Approach:Satellites provide synoptic views due to large swaths. Sun-synchronous LEO maintains similar illumination (constant solar zenith angle) for consistent reflectance comparison. Orbital mechanics set revisit intervals enabling monitoring of vegetation phenology, disasters, and urban change.
Step-by-Step Solution:
1) Large-area synoptic view: swaths hundreds to thousands of kilometres wide.2) Consistent illumination: near-fixed local time overpasses for radiometric comparability.3) Repetition: scheduled overpasses allow time-series analysis at scales from minutes (GEO) to weeks (LEO single-sat missions).Verification / Alternative check:Mission specs (e.g., Landsat ~16 days, Sentinel-2 ~5 days constellation, INSAT/GOES continuous) corroborate these points.
Why Other Options Are Wrong:
- Picking any single feature omits the broader capability; all are valid.
- None of these: Incorrect since satellites offer all listed advantages.
Common Pitfalls:Assuming “constant illumination” implies identical bidirectional reflectance every pass; surface anisotropy and atmosphere still matter.
Final Answer:All of these