[
  {
    "id": "natural-color",
    "name": "Natural color",
    "description": "RGB from visual assets",
    "type": "raster-tile",
    "options": "assets=image&asset_bidx=image|1,2,3",
    "minZoom": 6
  },
  {
    "id": "color-infrared",
    "name": "Color infrared",
    "description": "Highlights healthy (red) and unhealthy (blue/gray) vegetation.",
    "type": "raster-tile",
    "options": "assets=image&asset_bidx=image|4,1,2&color_formula=Sigmoidal RGB 15 0.35",
    "minZoom": 6
  },
  {
    "id": "normalized-difference-veg-inde",
    "name": "Normalized Difference Veg. Index (NDVI)",
    "description": "Normalized Difference Vegetation Index (NIR-Red)/(NIR+Red), darker green indicates healthier vegetation.",
    "type": "raster-tile",
    "options": "expression=(image_b4 - image_b1)/(image_b4 + image_b1)&rescale=-1,1&colormap_name=rdylgn",
    "minZoom": 6
  }
]