🔭 Space Glossary

Earth Observation

The sensors, techniques, and orbital parameters used to image and monitor Earth from space — from synthetic aperture radar and multispectral imaging to revisit time and ground resolution. 6 terms, each explained in plain language with key data and links to live trackers.

GSD GSD Pixel size on the ground — defines image resolution 0.31 m0.50 m MI Multispectral Imaging Capturing images in multiple wavelength bands 4–12 (visible + IR)Landsat (1972–present) RS Remote Sensing Gathering information about Earth without physical contact ~$8B+ (2025) RT Revisit Time How often a satellite can image the same spot Daily (global)5 days (at equator) SAR SAR Radar imaging that works through clouds and at night Earth Observation SW Swath Width Width of the ground strip imaged in one pass 290 km (10 m GSD)185 km (30 m GSD)

More glossary categories

All terms 🌐 Orbit Types 📐 Orbital Elements 📡 Tracking & Space Surveillance 🚀 Manoeuvres & Propulsion 🛡️ Debris & Space Safety 🛰️ Spacecraft Systems 🏗️ Launch & Ascent ☀️ Space Environment ⚖️ Policy & Regulation 📍 Navigation & Timing 📡 Amateur Radio & Satellites 🔭 Deep Space & Astrophysics 👨‍🚀 Human Spaceflight 🌐 Satellite Internet & Mega-Constellations 🪐 Planetary Science & Exploration