{
  "site_name": "Alleghany County LF (NC)",
  "landfill_id": 1042,
  "lat": 36.49357,
  "lon": -81.14299,
  "source": "mass_run",
  "measurement": {
    "hard_fail": false,
    "native_srs_label": "UTM17 WGS84 EPSG:32617",
    "epoch_a_date_nominal": "2016",
    "epoch_b_date_nominal": "2020",
    "epoch_dates_independently_verified": true,
    "usable_coverage_pct": 91.9,
    "n_stable_control_cells": 80457,
    "evidence_refs": [
      "epoch_a: kind=ept label='USGS_LPC_NC_Phase4_Alleghany_2016_LAS_2019' n_ground_points=8739453 runtime_s=103.6",
      "epoch_b: kind=ept label='NC_SpartaEQ_1_2020' n_ground_points=26957296 runtime_s=317.3"
    ],
    "meta": {
      "epoch_a": {
        "runtime_s": 103.55122471200002,
        "n_points": 8739453,
        "text_bytes": 270923055
      },
      "epoch_b": {
        "runtime_s": 317.28934230799996,
        "n_points": 26957296,
        "text_bytes": 835676188
      },
      "grid_nx": 500,
      "grid_ny": 500
    },
    "stable_control_offset_m": -0.0148,
    "stable_control_sigma_m": 0.0339,
    "detection_threshold_m": 0.1016,
    "volume_change_m3": 34.1,
    "uncertainty_m3": 3.7,
    "uncertainty_to_change_ratio": 0.108,
    "classification": "DECISION_USEFUL_CHANGE_DETECTED",
    "landfill_id": 1042,
    "name": "Alleghany County LF",
    "state": "NC",
    "lat": 36.49357,
    "lon": -81.14299,
    "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": 0.892,
    "declared_state": "Epoch A (2016) - reference/baseline surface",
    "observed_state": "Epoch B (2020) - current surface",
    "delta": {
      "volume_change_m3": 34.1,
      "uncertainty_m3": 3.7,
      "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_NC_Phase4_Alleghany_2016_LAS_2019' n_ground_points=8739453 runtime_s=103.6",
        "nominal_date": "2016",
        "dates_independently_verified": true,
        "n_ground_points": 8739453,
        "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": 3.7,
        "rights": "CC-BY 4.0"
      },
      {
        "source": "epoch_b: kind=ept label='NC_SpartaEQ_1_2020' n_ground_points=26957296 runtime_s=317.3",
        "nominal_date": "2020",
        "dates_independently_verified": true,
        "n_ground_points": 26957296,
        "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": 3.7,
        "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": "2016",
      "epoch_b_date_nominal": "2020",
      "epoch_dates_independently_verified": true,
      "usable_coverage_pct": 91.9,
      "n_stable_control_cells": 80457,
      "evidence_refs": [
        "epoch_a: kind=ept label='USGS_LPC_NC_Phase4_Alleghany_2016_LAS_2019' n_ground_points=8739453 runtime_s=103.6",
        "epoch_b: kind=ept label='NC_SpartaEQ_1_2020' n_ground_points=26957296 runtime_s=317.3"
      ],
      "meta": {
        "epoch_a": {
          "runtime_s": 103.55122471200002,
          "n_points": 8739453,
          "text_bytes": 270923055
        },
        "epoch_b": {
          "runtime_s": 317.28934230799996,
          "n_points": 26957296,
          "text_bytes": 835676188
        },
        "grid_nx": 500,
        "grid_ny": 500
      },
      "stable_control_offset_m": -0.0148,
      "stable_control_sigma_m": 0.0339,
      "detection_threshold_m": 0.1016,
      "volume_change_m3": 34.1,
      "uncertainty_m3": 3.7,
      "uncertainty_to_change_ratio": 0.108,
      "classification": "DECISION_USEFUL_CHANGE_DETECTED",
      "landfill_id": 1042,
      "name": "Alleghany County LF",
      "state": "NC",
      "lat": 36.49357,
      "lon": -81.14299,
      "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"
    }
  }
}