560 nm Optical

Canopy Pulse

Weekly NDVI change detection for the Hudson Valley

A small, personal experiment in weekly vegetation-index tracking, built on Sentinel-2 L2A via Planetary Computer, with a hexbin visualization of the change signal.

2025-08-14 41.70°N · 73.93°W 9 min

Placeholder case study. The real writeup lands once the project is built.

The idea

Vegetation indices from public optical imagery, summarized at H3 hex-tile resolution, updated weekly, over a region small enough to learn the dataset intimately. A personal-scale version of the kind of work you’d find at Regrow or Indigo — but here the point is to know the Hudson Valley’s vegetation signal cold, not to serve a customer.

Stack

  • Data: Sentinel-2 L2A via Microsoft Planetary Computer STAC.
  • Access: stackstac over COGs; xarray for the cube.
  • Index: NDVI, plus a few red-edge derivatives for comparison.
  • Aggregation: H3 hex binning via h3-py, materialized into DuckDB.
  • Viz: A MapLibre front-end with PMTiles for the hex layer.

Current state

Planning. The first week of data and a static hex map are the v0 milestone.

Colophon

Placeholder — will list data sources, tile extents, and libraries on publish.