{
  "site_name": "Sampson County LF (NC)",
  "landfill_id": 1132,
  "lat": 34.9634,
  "lon": -78.4486,
  "source": "mass_run",
  "measurement": {
    "hard_fail": false,
    "native_srs_label": "UTM17 WGS84 EPSG:32617",
    "epoch_a_date_nominal": "2014",
    "epoch_b_date_nominal": "2020",
    "epoch_dates_independently_verified": true,
    "usable_coverage_pct": 86.3,
    "n_stable_control_cells": 71906,
    "evidence_refs": [
      "epoch_a: kind=ept label='NC_SampsonCo_2014' n_ground_points=1273650 runtime_s=18.8",
      "epoch_b: kind=ept label='NC_HurricaneFlorence_5_2020' n_ground_points=11217381 runtime_s=77.2"
    ],
    "meta": {
      "epoch_a": {
        "runtime_s": 18.842961377999927,
        "n_points": 1273650,
        "text_bytes": 38209512
      },
      "epoch_b": {
        "runtime_s": 77.2445034939999,
        "n_points": 11217381,
        "text_bytes": 336521442
      },
      "grid_nx": 500,
      "grid_ny": 500
    },
    "stable_control_offset_m": 0.0257,
    "stable_control_sigma_m": 0.1196,
    "detection_threshold_m": 0.3587,
    "volume_change_m3": -244.2,
    "uncertainty_m3": 10.0,
    "uncertainty_to_change_ratio": 0.0409,
    "classification": "DECISION_USEFUL_CHANGE_DETECTED",
    "landfill_id": 1132,
    "name": "Sampson County LF",
    "state": "NC",
    "lat": 34.9634,
    "lon": -78.4486,
    "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": 0.959,
    "declared_state": "Epoch A (2014) - reference/baseline surface",
    "observed_state": "Epoch B (2020) - current surface",
    "delta": {
      "volume_change_m3": -244.2,
      "uncertainty_m3": 10.0,
      "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='NC_SampsonCo_2014' n_ground_points=1273650 runtime_s=18.8",
        "nominal_date": "2014",
        "dates_independently_verified": true,
        "n_ground_points": 1273650,
        "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": 10.0,
        "rights": "CC-BY 4.0"
      },
      {
        "source": "epoch_b: kind=ept label='NC_HurricaneFlorence_5_2020' n_ground_points=11217381 runtime_s=77.2",
        "nominal_date": "2020",
        "dates_independently_verified": true,
        "n_ground_points": 11217381,
        "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": 10.0,
        "rights": "CC-BY 4.0"
      }
    ],
    "recommended_next_action": "None - result is decisive.",
    "raw_measurement": {
      "hard_fail": false,
      "native_srs_label": "UTM17 WGS84 EPSG:32617",
      "epoch_a_date_nominal": "2014",
      "epoch_b_date_nominal": "2020",
      "epoch_dates_independently_verified": true,
      "usable_coverage_pct": 86.3,
      "n_stable_control_cells": 71906,
      "evidence_refs": [
        "epoch_a: kind=ept label='NC_SampsonCo_2014' n_ground_points=1273650 runtime_s=18.8",
        "epoch_b: kind=ept label='NC_HurricaneFlorence_5_2020' n_ground_points=11217381 runtime_s=77.2"
      ],
      "meta": {
        "epoch_a": {
          "runtime_s": 18.842961377999927,
          "n_points": 1273650,
          "text_bytes": 38209512
        },
        "epoch_b": {
          "runtime_s": 77.2445034939999,
          "n_points": 11217381,
          "text_bytes": 336521442
        },
        "grid_nx": 500,
        "grid_ny": 500
      },
      "stable_control_offset_m": 0.0257,
      "stable_control_sigma_m": 0.1196,
      "detection_threshold_m": 0.3587,
      "volume_change_m3": -244.2,
      "uncertainty_m3": 10.0,
      "uncertainty_to_change_ratio": 0.0409,
      "classification": "DECISION_USEFUL_CHANGE_DETECTED",
      "landfill_id": 1132,
      "name": "Sampson County LF",
      "state": "NC",
      "lat": 34.9634,
      "lon": -78.4486,
      "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"
    }
  }
}