{
  "site_name": "Greenwood Street LF (MA)",
  "landfill_id": 802,
  "lat": 42.218739,
  "lon": -71.789885,
  "source": "mass_run",
  "measurement": {
    "hard_fail": false,
    "native_srs_label": "UTM19 WGS84 EPSG:32619",
    "epoch_a_date_nominal": "2015",
    "epoch_b_date_nominal": "2021",
    "epoch_dates_independently_verified": true,
    "usable_coverage_pct": 90.7,
    "n_stable_control_cells": 78958,
    "evidence_refs": [
      "epoch_a: kind=ept label='USGS_LPC_MA_ME_MA_QL2_UTM19_L1_2015_LAS_2018' n_ground_points=3021164 runtime_s=20.7",
      "epoch_b: kind=ept label='MA_CentralEastern_1_2021' n_ground_points=10424615 runtime_s=55.3"
    ],
    "meta": {
      "epoch_a": {
        "runtime_s": 20.700735352000038,
        "n_points": 3021164,
        "text_bytes": 93656096
      },
      "epoch_b": {
        "runtime_s": 55.308460935000085,
        "n_points": 10424615,
        "text_bytes": 323163077
      },
      "grid_nx": 500,
      "grid_ny": 500
    },
    "stable_control_offset_m": -0.0392,
    "stable_control_sigma_m": 0.0899,
    "detection_threshold_m": 0.2696,
    "volume_change_m3": 2798.4,
    "uncertainty_m3": 18.2,
    "uncertainty_to_change_ratio": 0.0065,
    "classification": "DECISION_USEFUL_CHANGE_DETECTED",
    "landfill_id": 802,
    "name": "Greenwood Street LF",
    "state": "MA",
    "lat": 42.218739,
    "lon": -71.789885,
    "site_note": "poligono sintetico (buffer 200x200m sobre coordenada LMOP real), NO el parcel legal exacto",
    "datum_note": "UTM WGS84, no NAD83(2011) especifico por estado - ver docstring de lmop_mass_runner.py"
  },
  "verdict": {
    "verdict": "CHANGE_CONFIRMED",
    "confidence": 0.994,
    "declared_state": "Epoch A (2015) - reference/baseline surface",
    "observed_state": "Epoch B (2021) - current surface",
    "delta": {
      "volume_change_m3": 2798.4,
      "uncertainty_m3": 18.2,
      "unit": "m3"
    },
    "sensor_agreement": {
      "status": "not_applicable_single_sensor",
      "note": "physical_change compares two epochs of the same sensor modality (LiDAR vs. LiDAR) - there is no second independent sensor to cross-check against today, unlike china_industrial_reality's multi-signal (NDVI/NDBI/SAR) discipline. The stable_control_offset_m/stable_control_sigma_m fields are a real internal consistency check (calibration against known-stable ground), not a second sensor."
    },
    "evidence": [
      {
        "source": "epoch_a: kind=ept label='USGS_LPC_MA_ME_MA_QL2_UTM19_L1_2015_LAS_2018' n_ground_points=3021164 runtime_s=20.7",
        "nominal_date": "2015",
        "dates_independently_verified": true,
        "n_ground_points": 3021164,
        "hash": null,
        "hash_note": "No cryptographic hash of the source point cloud is computed today - real gap, not hidden.",
        "method_version": "measure_physical_change (unmodified core function across all 4 validated sites)",
        "uncertainty_m3": 18.2,
        "rights": "CC-BY 4.0"
      },
      {
        "source": "epoch_b: kind=ept label='MA_CentralEastern_1_2021' n_ground_points=10424615 runtime_s=55.3",
        "nominal_date": "2021",
        "dates_independently_verified": true,
        "n_ground_points": 10424615,
        "hash": null,
        "hash_note": "No cryptographic hash of the source point cloud is computed today - real gap, not hidden.",
        "method_version": "measure_physical_change (unmodified core function across all 4 validated sites)",
        "uncertainty_m3": 18.2,
        "rights": "CC-BY 4.0"
      }
    ],
    "recommended_next_action": "None - result is decisive.",
    "raw_measurement": {
      "hard_fail": false,
      "native_srs_label": "UTM19 WGS84 EPSG:32619",
      "epoch_a_date_nominal": "2015",
      "epoch_b_date_nominal": "2021",
      "epoch_dates_independently_verified": true,
      "usable_coverage_pct": 90.7,
      "n_stable_control_cells": 78958,
      "evidence_refs": [
        "epoch_a: kind=ept label='USGS_LPC_MA_ME_MA_QL2_UTM19_L1_2015_LAS_2018' n_ground_points=3021164 runtime_s=20.7",
        "epoch_b: kind=ept label='MA_CentralEastern_1_2021' n_ground_points=10424615 runtime_s=55.3"
      ],
      "meta": {
        "epoch_a": {
          "runtime_s": 20.700735352000038,
          "n_points": 3021164,
          "text_bytes": 93656096
        },
        "epoch_b": {
          "runtime_s": 55.308460935000085,
          "n_points": 10424615,
          "text_bytes": 323163077
        },
        "grid_nx": 500,
        "grid_ny": 500
      },
      "stable_control_offset_m": -0.0392,
      "stable_control_sigma_m": 0.0899,
      "detection_threshold_m": 0.2696,
      "volume_change_m3": 2798.4,
      "uncertainty_m3": 18.2,
      "uncertainty_to_change_ratio": 0.0065,
      "classification": "DECISION_USEFUL_CHANGE_DETECTED",
      "landfill_id": 802,
      "name": "Greenwood Street LF",
      "state": "MA",
      "lat": 42.218739,
      "lon": -71.789885,
      "site_note": "poligono sintetico (buffer 200x200m sobre coordenada LMOP real), NO el parcel legal exacto",
      "datum_note": "UTM WGS84, no NAD83(2011) especifico por estado - ver docstring de lmop_mass_runner.py"
    }
  }
}