TRANSPARENT GEOSPATIAL METHODS

From satellite to spatial insight.

Processing workflow

Satellite detection → NASA FIRMS acquisition → cleaning and normalisation → hosted persistent storage → temporal filtering → spatial analysis → Web GIS visualisation.

Coordinates and distance

Interchange coordinates use WGS84 (EPSG:4326), with longitude first in GeoJSON. The hosted edition uses spherical haversine distance with mean Earth radius 6371.0088 km and spherical destination-point buffers. These approximate distances may differ from the local PostGIS spheroidal calculations.

Time and provenance

Acquisition dates and times are preserved in UTC. Default queries use the latest seven imported acquisition dates, which may be historical. Calendar presets use UTC dates; they are not rolling 24-hour windows. Raw source fields and retrieval timestamps remain stored for audit.

Confidence and heatmaps

VIIRS low, nominal and high flags are retained and normalised. MODIS numeric confidence is grouped as low (<30), nominal (30–79) and high (≥80), while retaining original values. Confidence is a detection quality indicator. Heatmaps weight each displayed point equally and do not measure haze concentration or fire severity.

State aggregation

Validated, licensed Malaysia state polygons must be imported separately. No licensed state polygons are currently imported; administrative summaries are unavailable. Counts include detections rather than unique fire events. Boundary-edge detections may appear in multiple adjoining states. Area density and district aggregation are planned.

Interpretation limits

A thermal anomaly is not a confirmed ground fire. Cloud, overpass timing, resolution and sensor differences affect detection. Proximity alone cannot establish smoke transport or transboundary attribution. JAS station IPU/API snapshots and dated MAIAC aerosol browse imagery provide additional context. Their timestamps are independent of hotspot filters; AOD is not surface PM2.5. Selected-location current model wind from Open-Meteo provides additional context; its directional arrow does not model smoke transport. Historical wind alignment, PM2.5 concentrations and the experimental risk indicator remain planned.