Swath

The strip of ground a satellite images in a single pass. A wide swath covers more area per orbit but usually at coarser resolution.

Why it matters

Swath width determines revisit — MODIS’s ~2330 km swath sees the whole Earth daily; Landsat’s 185 km swath needs 16 days to tile the globe.

Where you’ll meet it

• MODIS (on Terra/Aqua) sweeps a ~2330 km swath, so its instruments map nearly the entire planet every day — great for tracking fires, dust, and ocean color.
• VIIRS (on Suomi NPP and NOAA-20) pushes even wider at ~3060 km, with no gaps between orbits, which is why it powers daily global true-color and nighttime-lights imagery.
• Landsat 8/9 trade width for detail: a 185 km swath that takes 16 days to tile the globe, ideal for field-scale land and water studies.
• Sentinel-1 radar flips swath into a deliberate trade-off — its narrow Stripmap mode gives fine detail, while the ~250 km Interferometric Wide mode covers more ground for routine monitoring.

In plain terms

Think of mowing a lawn — a wide mower (big swath) finishes fast but cuts rough; a narrow mower (small swath) is slow but precise.