SST Resolution: 750m vs. 1km vs. 25km Explained
Native resolution on Chlorofishy ranges from about 750m for a VIIRS chlorophyll pass down to about 25km for AMSR2 microwave SST: a difference of roughly 1,000x in the ground area one pixel represents, and it changes what each layer can actually show you.
Resolution by product
| Product | Native resolution | Type |
|---|---|---|
| VIIRS chlorophyll pass | ~750m | Raw pass, daytime only |
| MODIS Aqua SST/chlorophyll pass | ~1km | Raw pass |
| SST composite (GHRSST MUR L4) | 1km | Composite analysis |
| VIIRS SST pass | ~2km | Raw pass |
| Chlorophyll composite (VIIRS L3) | 4km | Composite analysis |
| Sentinel-3 OLCI chlorophyll | 4km native, ~8km as processed | Composite analysis |
| AMSR2 microwave SST | ~25km | Raw pass, cloud-penetrating |
What determines a sensor's resolution
Optical and infrared sensors (VIIRS, MODIS) resolve fine detail because visible and infrared wavelengths are short enough for a modest instrument to focus sharply from orbit. Microwave sensors (AMSR2) use a much longer wavelength (the property that lets them see through cloud), and a longer wavelength physically requires a larger antenna footprint to resolve the same ground area. See microwave SST for that tradeoff in full.
Never upscaled beyond native resolution
Chlorofishy's pipeline caps every tile's zoom level at what its source resolution actually supports, so a 4km chlorophyll composite is never stretched to look as sharp as a 750m pass. This is one of the product's non-negotiable data-integrity rules: resolution you see on the map is resolution the sensor actually delivered, never invented in rendering.
Compare a sharp pass against a coarser composite side by side on the chlorophyll map, or see the full sensor list at data sources. For how resolution compares across the category, see the best SST charts for offshore fishing, compared. Back to Learn.