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Home Academy Satellite Missions 101 Optical vs radar imaging
LESSON 03 OF 6

Optical vs radar imaging

Beginner ~10 min Slide deck Free

Earth observation satellites use two fundamentally different sensor technologies. Understanding the difference explains why certain missions use certain orbits and why coverage depends on more than just orbital position.

Earth observation satellites use two fundamentally different sensor technologies. Understanding the difference explains why certain missions use certain orbits and why coverage depends on more than just orbital position.

What this lesson covers

Resolution vs Swath Tradeoff

Both optical and SAR systems face the same fundamental constraint: higher resolution means narrower swath.

Why Orbit Connects to Sensor Type

The sensor type directly influences orbit requirements and coverage strategy.

Key facts

💡Planet Labs' SkySat captures 0.5m resolution scenes. Their Dove constellation covers wider strips at 3–5m — each optimised for different use cases.
💡ICEYE (SAR) offers sub-1-hour tasking at some locations globally because night+day capability lets them use every available orbital pass.
Optical = sunlight-limited. SAR = all-weather, day/night capability.

Knowing which sensor type a satellite uses tells you when it can collect — and when it can't. Cloud-heavy or winter regions often see optical satellites unable to acquire while SAR continues uninterrupted.

All lessons in Satellite Missions 101
01Comms vs EO vs science vs nav~9 min02Why some look stationary~9 min03Optical vs radar imaging~10 min04Weather sats vs EO sats~9 min05Signals intelligence~9 min06Lifetime + why things fail~9 min
← Why some look stationaryAll 6 LessonsWeather sats vs EO sats →
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