Sentinel-3 OLCI — 21 bands incl. 620 nm (phycocyanin) & 709 nm (red edge)

ESA / EUMETSAT / Copernicus

Specification

Code: AL04
Reliability: A+ Gold
Variables delivered: PHYCOCYANIN (620 nm) , chlorophyll (MCI, NDCI), Rrs 412/555 for SWM, TSM
Resolution: 300 m full resolution
Cadence: ~1-2 days (S3A + S3B)
Coverage: 2016-10 → present
Cost: FREE
Login required: No (GEE) / free registration (CMEMS, EUMETSAT)
Latency: ~1-3 days
CSV direct?: Via GEE or toolbox
Sensor: Sentinel-3 OLCI — 300 m, 1.5 day revisit

Chakaria HDSS YES Rural COASTAL

CRITICAL — resolves the Matamuhuri estuary AND has the 620 nm cyanobacteria band

Matlab HDSS YES Rural riverine

CRITICAL — the Meghna is 2-6 km wide, so 300 m works beautifully · near-daily revisit

Dhaka City PARTIAL Urban inland

MARGINAL — only the widest reaches of the Buriganga and the largest lakes

Route: GEE (TOA only) · CMEMS · EUMETSAT Data Store API · CDSE
Endpoint / asset ID: COPERNICUS/S3/OLCI (TOA — bring your own atmospheric correction) | CMEMS OLCI L2 WFR
Pipeline step: 3 Extract
Documentation: https://developers.google.com/earth-engine/datasets/catalog/COPERNICUS_S3_OLCI

cd 01_Scripts
python 10_algae_daily_3sites.py --sensors s3

VALIDATION STATUS

OLCI L2 WFR validated for coastal water · phycocyanin retrieval is still research-grade

KNOWN LIMITATION

GEE holds only TOA radiance — you must run C2RCC / POLYMER / ACOLITE yourself or pull L2 from CMEMS. Starts 2016.