# JJ-FAST (JICA-JAXA Forest Early Warning System in the Tropics)
*data products*

## Specifications
- **level**: L3
- **distributor**: jaxa
- **gsd m**: {"native":100}
- **access model**: open
- **licence**: Registration required for full access
- **primary data portal url**: https://www.eorc.jaxa.jp/jjfast/
- **use cases**: ["Near-real-time tropical deforestation alert independent of cloud cover","Government forest monitoring in persistent-cloud regions (Southeast Asia, Congo Basin, Amazon)","Supply chain deforestation risk screening for EUDR-regulated commodities","Complementary SAR-based alert to optical systems (GLAD-L, GLAD-S2, RADD)"]
- **practical limitations**: ["100 m resolution limits detection of small-area clearings below approximately 1 ha","Approximately 42-day product publication cycle (driven by ALOS-2 14-day orbital repeat plus ScanSAR tile composition and processing latency) is slower than RADD (6 to 12 day) and slower than optical systems under clear-sky conditions","Accuracy statistics not confirmed from tier 1 source (primary algorithm paper paywalled)","Minimum mapping unit not stated in accessible documentation"]
- **known artefacts**: ["Terrain-induced false detections suppressed by ALOS World 3D DEM slope mask added July 2023; residual artefacts possible in steep terrain","Speckle inherent to SAR; HH+HV dual-pol algorithm mitigates single-channel noise"]
- **last verified date**: "2026-05-18T00:00:00.000Z"
- **verified by**: sw
- **claim status**: unclaimed
- **deployment context**: orbital

## Compositional position
- defor (topics) --[topic_capabilities]--> JJ-FAST (JICA-JAXA Forest Early Warning System in the Tropics)

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Source: https://eo-atlas.org/data_products/jj-fast-alerts
Maintainer: SpectraWorks B.V. (CC-BY 4.0)