{
  "schemaVersion": 1,
  "sourceId": "london-lst-samples",
  "evidence": "derived",
  "source": "https://www.usgs.gov/landsat-missions/landsat-collection-2-surface-temperature",
  "catalogue": "https://developers.google.com/earth-engine/datasets/catalog/LANDSAT_LC09_C02_T1_L2",
  "license": "Public domain",
  "attribution": "Landsat Collection 2 Level-2 image courtesy of the U.S. Geological Survey.",
  "retrieved": "2026-10-07",
  "derived": "2026-10-09",
  "scene": {
    "CLOUD_COVER": 5.94,
    "DATE_ACQUIRED": "2025-07-10",
    "LANDSAT_PRODUCT_ID": "LC09_L2SP_201024_20250710_20250711_02_T1",
    "SCENE_CENTER_TIME": "10:52:06.7850330Z",
    "SPACECRAFT_ID": "LANDSAT_9",
    "WRS_PATH": 201,
    "WRS_ROW": 24,
    "local_valid_london": 0.9698808111423002,
    "local_valid_soho": 1,
    "system:index": "2_LC09_201024_20250710",
    "system:time_start": 1752144726785
  },
  "acquisitionUtc": "2025-07-10T10:52:06.785000+00:00",
  "master": {
    "file": ".cache/london-climate/london-lst.npy",
    "sha256": "3f80048d37621a48572a504262833b51bbe20bba0d7de5a5cbefa6fe599a662a",
    "metadataSha256": "422f09e301bc4b08a1362ea8c15dd70856ccbe5b54fd7ecaacb8f7b4504f13e0",
    "provenanceRecord": "/data/london-climate-manifest.json",
    "purpose": "Numerical sampling, independent of colour display and later wider exports"
  },
  "grid": {
    "crs": "EPSG:4326",
    "bbox": [
      -0.38,
      51.36,
      0.36,
      51.78
    ],
    "dimensions": [
      1536,
      1400
    ],
    "northUp": true,
    "transform": [
      0.00048177083333333335,
      0,
      -0.38,
      0,
      -0.0003000000000000012,
      51.78
    ]
  },
  "nativeThermalPixelM": 100,
  "deliveredProductGridM": 30,
  "method": {
    "footprintSelection": "Two equal 250 m BNG circles at pre-existing stored centres, fixed before temperature inspection",
    "cellSelection": "Export pixel centres within each circle; equal weighting; no temperature filtering",
    "resampling": "Nearest sampling retained from the original numerical export; no thermal sharpening",
    "quality": {
      "QA_PIXEL_reject_bits": {
        "fill": 0,
        "dilated_cloud": 1,
        "cirrus": 2,
        "cloud": 3,
        "cloud_shadow": 4,
        "snow": 5
      },
      "QA_RADSAT_required_value": 0,
      "rejectZeroST": true,
      "uncertaintyCutoff": null,
      "note": "Uncertainty is retained and reported, not hidden by an arbitrary acceptance cutoff."
    },
    "qualityScope": "Provider QA applied by the parent export; retained missing/rejected sentinel -9999 is excluded. Raw QA bands are not re-read here.",
    "providerUncertainty": "ST_QA multiplied by 0.01 K, retained from the same valid cells; no arbitrary uncertainty cutoff",
    "uncertaintyInterpretation": "Provider per-cell retrieval uncertainty, not a confidence interval for either footprint median or their difference",
    "sceneSelection": "Highest locally QA-valid fraction across London at a 250 m sampling grid; then Soho coverage; then acquisition date. Clear coverage is availability, not temperature accuracy.",
    "candidateCount": 16,
    "search": {
      "bbox": [
        -0.38,
        51.36,
        0.36,
        51.78
      ],
      "start": "2025-06-01",
      "endExclusive": "2025-09-01",
      "processingLevel": "L2SP",
      "maximumSceneCloudPercentExclusive": 80,
      "londonCoverageSampleM": 250,
      "sohoCoverageSampleM": 90
    },
    "builder": "scripts/build-london-surface-temperature-samples.py"
  },
  "samples": [
    {
      "id": "regents-park",
      "label": "Regent's Park",
      "centre": {
        "longitude": -0.1537641,
        "latitude": 51.5301326
      },
      "centreSource": {
        "record": "/data/piccadilly-landmarks.json",
        "feature": "OSM relation 1384127",
        "href": "https://www.openstreetmap.org/relation/1384127",
        "method": "OSM Nominatim representative point for the park relation, not the similarly named station. Orientation point only.",
        "license": "ODbL 1.0",
        "attribution": "© OpenStreetMap contributors"
      },
      "evidence": "derived",
      "footprint": {
        "shape": "circle",
        "crs": "EPSG:27700",
        "centre": [
          528163.1805872503,
          182862.27914114023
        ],
        "radiusM": 250.0,
        "areaM2": 196349.54084936206,
        "scope": "Local sample, not the whole named place or a mapped land-cover polygon"
      },
      "exportGridSpacingM": [
        33.43234968210028,
        33.377522526937106
      ],
      "gridCells": {
        "selected": 175,
        "valid": 175,
        "rejectedOrMissing": 0,
        "validFraction": 1.0,
        "meaning": "Export grid cells, not independent thermal observations"
      },
      "geodesicCrosscheck": {
        "ellipsoid": "WGS84",
        "sameSelectedCells": true
      },
      "temperatureC": {
        "minimum": 33.56085968017578,
        "p25": 35.83042526245117,
        "median": 36.695186614990234,
        "p75": 37.50867462158203,
        "maximum": 39.21426773071289
      },
      "providerUncertaintyK": {
        "minimum": 2.309999942779541,
        "p25": 2.369999885559082,
        "median": 2.4100000858306885,
        "p75": 2.4800000190734863,
        "maximum": 2.75
      }
    },
    {
      "id": "soho",
      "label": "Soho",
      "centre": {
        "longitude": -0.13425145087516513,
        "latitude": 51.51350046006477
      },
      "centreSource": {
        "record": "/data/soho-raster-manifest.json",
        "feature": "cameraCentre",
        "method": "Existing declared BNG frame centre, not a surveyed neighbourhood boundary"
      },
      "evidence": "derived",
      "footprint": {
        "shape": "circle",
        "crs": "EPSG:27700",
        "centre": [
          529563.7523807205,
          181047.05451059516
        ],
        "radiusM": 250.0,
        "areaM2": 196349.54084936206,
        "scope": "Local sample, not the whole named place or a mapped land-cover polygon"
      },
      "exportGridSpacingM": [
        33.44453043354728,
        33.377427355195906
      ],
      "gridCells": {
        "selected": 176,
        "valid": 176,
        "rejectedOrMissing": 0,
        "validFraction": 1.0,
        "meaning": "Export grid cells, not independent thermal observations"
      },
      "geodesicCrosscheck": {
        "ellipsoid": "WGS84",
        "sameSelectedCells": true
      },
      "temperatureC": {
        "minimum": 40.967708587646484,
        "p25": 42.77926158905029,
        "median": 43.28512954711914,
        "p75": 43.699562072753906,
        "maximum": 44.65233612060547
      },
      "providerUncertaintyK": {
        "minimum": 3.130000114440918,
        "p25": 3.190000057220459,
        "median": 3.2699999809265137,
        "p75": 3.3299999237060547,
        "maximum": 3.9800000190734863
      }
    }
  ],
  "comparison": {
    "statistic": "Soho median minus Regent's Park median",
    "differenceOfMediansC": 6.589942932128906,
    "interpretation": "Descriptive contrast between these local samples at one overpass, not a causal cooling effect or significance test"
  },
  "limits": [
    "Local circular samples, not whole-park, whole-Soho or land-cover-specific statistics.",
    "Surface temperature at one daytime overpass, not air temperature, pedestrian radiant exposure, indoor temperature, building heat loss or EPC.",
    "Native thermal support is 100 m; the 30 m delivery and approximately 33 m export grids do not create independent finer thermal observations.",
    "Provider uncertainty, emissivity and atmospheric errors remain; no local field calibration, confidence interval, UHI magnitude or intervention effect is claimed.",
    "USGS documents small-target blockiness, cloud-adjacent errors and a vegetation-adjustment emissivity anomaly.",
    "The NDVI acquisition is 25 August 2025; it cannot establish a contemporaneous vegetation-temperature relationship with this July overpass."
  ]
}