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.
- +DATA HUBSwhere the data physically comes from
- −DATASET TYPESgrouped by what kind of water they see
- +1. Ocean colour (hyperspectral)1 datasets
- +1. Ocean colour (merged)3 datasets
- +1. Ocean colour (single sensor)5 datasets
- −2. Inland/coastal high-res6 datasets
- ·AL03 · Sentinel-2 MSI Level-2A (harmonised)A+ Gold10 m (B2,3,4,8) / 20 m (B5 red-edge 705 nm) · 5 days (2-3 d with S2… · 2015-06 (L1C) / 2017-03 (L2A)→present
- ·AL04 · Sentinel-3 OLCI — 21 bands incl. 620 nm (phyc…A+ Gold300 m full resolution · ~1-2 days (S3A + S3B) · 2016-10→present
- ·AL05 · Landsat 5 / 7 / 8 / 9 Collection 2 Level-2A+ Gold30 m · 16 days per satellite… · 1984 (L5) / 1999 (L7) / 2013 (L8→present
- ·AL14 · Harmonized Landsat Sentinel-2 (HLS) v2.0B Usable30 m · 2-3 days combined · 2013 (L30) / 2015 (S30)→present
- ·AL16 · MODIS MOD09GA/GQ daily surface reflectance (2…B Usable250 m (b1,b2) / 500 m · DAILY · 2000-02-24→present
- ·AL18 · Sentinel-2 Level-1C + ACOLITE Dark Spectrum F…B Usable10-20 m · 5 days · 2015-06→present
- +3. Lake / inland operational2 datasets
- +4. Model / reanalysis1 datasets
- +5. Discovery / portal1 datasets
- +6. Derived / uncalibrated2 datasets
- +7. In-situ validation5 datasets
- −SITE-WISEwhat actually applies at each site
- +Chakaria HDSSChakariaRural COASTAL · 10 km to sea · 16 datasets apply
- −Matlab HDSSMatlabRural riverine · 250 km to sea · 11 datasets apply
- ·AL03 · Sentinel-2 MSI Level-2A (harmonised)5 days (2-3 d with S2C fr… · 10 m (B2,3,4,8) / 20 m (B5 red-edge 705 nm)
- ·AL04 · Sentinel-3 OLCI — 21 bands incl. 620 nm (ph…~1-2 days (S3A + S3B) · 300 m full resolution
- ·AL05 · Landsat 5 / 7 / 8 / 9 Collection 2 Level-216 days per satellite (~8… · 30 m
- ·AL14 · Harmonized Landsat Sentinel-2 (HLS) v2.02-3 days combined · 30 m
- ·AL16 · MODIS MOD09GA/GQ daily surface reflectance …DAILY · 250 m (b1,b2) / 500 m
- ·AL18 · Sentinel-2 Level-1C + ACOLITE Dark Spectrum…5 days · 10-20 m
- ·AL19 · GEE Sen2Cor L2A NDCI → chlorophyll polynomi…5 days · 10-20 m
- ·AL20 · Landsat green/blue chlorophyll proxy (2000-…16 days · 30 m
- ·AL22 · SeaBASS — NASA bio-Optical Archive and Stor…Per cruise/campaign · Point
- ·AL23 · GLORIA — Global Reflectance community datas…Per sample · Point
- ·AL26 · icddr,b environmental microbiology archives…FORTNIGHTLY · Point (pond)
- +Dhaka CityDhakaUrban inland · 300 km to sea · 9 datasets apply
- +DURATION & CAPTURE CADENCEdaily · weekly · 10-day · 16-day · monthly
- +VARIABLESwhat is computed from the bands
- +LIMITATIONSwhy not — typed and severity-ranked
- +PAPERSthe evidence, DOI-linked
2. Inland/coastal high-res
AL16 · MODIS MOD09GA/GQ daily surface reflectance (250-500 m)
NASA LP DAAC
B Usable
FREE
NO ACCOUNT
Source · duration · capture cadence
- Data source
- NASA LP DAAC
- Access route
- GEE
- Endpoint / asset
MODIS/061/MOD09GA · MOD09GQ- Duration
- 2000-02-24 → present
- Capture cadence
- DAILY
- Resolution
250 m (b1,b2) / 500 m- Delivers
- FAI, NDVI-on-water, floating-bloom detection over LARGE water bodies only
- Command
10_algae_daily_3sites.py --sensors modis
Why it is used for cholera.
Well validated for land · water use is non-standard
Why not — catalogue limitation. Land-optimised atmospheric correction. Mixed land/water pixels dominate at the banks — erode the water mask by 2 pixels before extracting.
Site applicability
| Site | Verdict | Why |
|---|---|---|
| Chakaria HDSS | PARTIAL | MEDIUM — can see the Matamuhuri estuary mouth and nearshore plume |
| Matlab HDSS | YES | USEFUL — the Meghna is wide enough for 250 m, giving you a DAILY 2000-2026 bloom record |
| Dhaka City | NOT APPLICABLE | NOT APPLICABLE — every Dhaka water body is sub-250 m |
Reliable · accessible · authentic
B Usable
Reliability tier
OPEN
Accessible
NASA LP DAAC
Authentic — operator
Typed limitations (1)
CRITICAL 250 m works on the Meghna and nowhere else in this study spatial blocks Dhaka
MODIS 250 m is the only genuinely daily inland option back to 2000, but it needs a wide channel. The Meghna at 2-6 km qualifies. Village ponds, shrimp ponds and Dhaka lakes are all far below one pixel.
What to do: Restrict MODIS to the Meghna main channel at Matlab and the Matamuhuri mouth at Chakaria. Do not run it over Dhaka - it returns a column of nulls and wastes an hour.