SatHDSS
Network panel

Algae Dataset

Every data hub, dataset, sensor, variable, paper and limitation in one tree — and for each: where it comes from, how far back it goes, how often it captures, why it belongs in a cholera study, and why it does not work everywhere.

Highlight site All three Chakaria HDSS Matlab HDSS Dhaka City Choosing a site greys out everything that does not apply there.

1. Ocean colour (single sensor)

AL06 · MODIS-Aqua Level-3 SMI
NASA OB.DAAC
A Reliable FREE NO ACCOUNT

Source · duration · capture cadence

Data source
NASA OB.DAAC
Access route
GEE · OB.DAAC file_search API · ERDDAP · OPeNDAP
Endpoint / asset
NASA/OCEANDATA/MODIS-Aqua/L3SMI | oceandata.sci.gsfc.nasa.gov/api/file_search
Duration
2002-07 → present
Capture cadence
Daily / 8-day / monthly
Resolution
4.6 km
Delivers
Chlorophyll-a (OC3M), Rrs 412/443/488/531/547/555/667, FAI-capable bands, SST, PAR, Kd490, POC
Command
10_algae_daily_3sites.py --sensors ocean
Why it is used for cholera. The most-validated ocean-colour record in existence
Why not — catalogue limitation. OC3M overestimates chlorophyll in turbid case-2 water near the delta. Flag using Rrs667.

Site applicability

SiteVerdictWhy
Chakaria HDSS YES YES — long single-sensor record for the Chakaria coastal box
Matlab HDSS PARTIAL Regional forcing only
Dhaka City NOT APPLICABLE NOT APPLICABLE

Reliable · accessible · authentic

A Reliable
Reliability tier
OPEN
Accessible
NASA OB.DAAC
Authentic — operator
Documentation: https://developers.google.com/earth-engine/datasets/catalog/NASA_OCEANDATA_MODIS-Aqua_L3SMI

Typed limitations (1)

HIGH OC3M overestimates chlorophyll in turbid case-2 water algorithmic

The standard band-ratio algorithm assumes optically deep case-1 water. Inside the Matamuhuri estuary and near the coast, suspended sediment and CDOM inflate the retrieval.

What to do: Valid offshore of Chakaria, not inside the estuary. Use the coastal box for the offshore signal and Sentinel-2 for the estuary itself.
Full dataset page →