{
  "site_name": "Ca na Putxa (Eivissa, Espana)",
  "landfill_id": null,
  "lat": 38.9629,
  "lon": 1.4045,
  "source": "hand_run",
  "measurement": {
    "hard_fail": false,
    "native_srs_label": "UTM31N ETRS89 (EPSG:25831)",
    "epoch_a_date_nominal": "2019-11-25",
    "epoch_b_date_nominal": "2024-04-16",
    "epoch_dates_independently_verified": true,
    "usable_coverage_pct": 83.5,
    "n_stable_control_cells": 24166,
    "evidence_refs": [
      "epoch_a: kind=las_files label='PNOA-2019-BAL-368-4312' n_ground_points=1903104 runtime_s=4.1",
      "epoch_b: kind=las_files label='PNOA-2023-BAL-368-4312+368-4311+369-4312+369-4311' n_ground_points=11980654 runtime_s=34.1"
    ],
    "meta": {
      "epoch_a": {
        "runtime_s": 4.058789845556021,
        "n_points": 1903104,
        "text_bytes": 57894522
      },
      "epoch_b": {
        "runtime_s": 34.055402738042176,
        "n_points": 11980654,
        "text_bytes": 364292615
      },
      "grid_nx": 878,
      "grid_ny": 744
    },
    "stable_control_offset_m": -0.1992,
    "stable_control_sigma_m": 0.3124,
    "detection_threshold_m": 0.9373,
    "volume_change_m3": 310357.2,
    "uncertainty_m3": 182.9,
    "uncertainty_to_change_ratio": 0.0006,
    "classification": "DECISION_USEFUL_CHANGE_DETECTED"
  },
  "verdict": {
    "verdict": "CHANGE_CONFIRMED",
    "confidence": 0.999,
    "declared_state": "Epoch A (2019-11-25) - reference/baseline surface",
    "observed_state": "Epoch B (2024-04-16) - current surface",
    "delta": {
      "volume_change_m3": 310357.2,
      "uncertainty_m3": 182.9,
      "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=las_files label='PNOA-2019-BAL-368-4312' n_ground_points=1903104 runtime_s=4.1",
        "nominal_date": "2019-11-25",
        "dates_independently_verified": true,
        "n_ground_points": 1903104,
        "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": 182.9,
        "rights": "CC-BY 4.0"
      },
      {
        "source": "epoch_b: kind=las_files label='PNOA-2023-BAL-368-4312+368-4311+369-4312+369-4311' n_ground_points=11980654 runtime_s=34.1",
        "nominal_date": "2024-04-16",
        "dates_independently_verified": true,
        "n_ground_points": 11980654,
        "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": 182.9,
        "rights": "CC-BY 4.0"
      }
    ],
    "recommended_next_action": "None - result is decisive.",
    "raw_measurement": {
      "hard_fail": false,
      "native_srs_label": "UTM31N ETRS89 (EPSG:25831)",
      "epoch_a_date_nominal": "2019-11-25",
      "epoch_b_date_nominal": "2024-04-16",
      "epoch_dates_independently_verified": true,
      "usable_coverage_pct": 83.5,
      "n_stable_control_cells": 24166,
      "evidence_refs": [
        "epoch_a: kind=las_files label='PNOA-2019-BAL-368-4312' n_ground_points=1903104 runtime_s=4.1",
        "epoch_b: kind=las_files label='PNOA-2023-BAL-368-4312+368-4311+369-4312+369-4311' n_ground_points=11980654 runtime_s=34.1"
      ],
      "meta": {
        "epoch_a": {
          "runtime_s": 4.058789845556021,
          "n_points": 1903104,
          "text_bytes": 57894522
        },
        "epoch_b": {
          "runtime_s": 34.055402738042176,
          "n_points": 11980654,
          "text_bytes": 364292615
        },
        "grid_nx": 878,
        "grid_ny": 744
      },
      "stable_control_offset_m": -0.1992,
      "stable_control_sigma_m": 0.3124,
      "detection_threshold_m": 0.9373,
      "volume_change_m3": 310357.2,
      "uncertainty_m3": 182.9,
      "uncertainty_to_change_ratio": 0.0006,
      "classification": "DECISION_USEFUL_CHANGE_DETECTED"
    }
  }
}