{
  "schema_version": 1,
  "survey_grade": false,
  "method": "Manual, spatially distributed image landmark controls; least-squares 2D similarity (rotation, uniform scale, translation), not a projective warp. Seven fitted controls and three withheld image checks. Plan pp.8/9 first registered to p.7 with SIFT/RANSAC overlap links.",
  "ortho": {
    "asset": "assets/rough-point-construction/data/ortho.webp",
    "capture": "2721hilham-4cm",
    "crs": "EPSG:32616",
    "width": 1675,
    "height": 3072,
    "west": 638556.25,
    "north": 4030929.75,
    "east": 639281.25,
    "south": 4029599.75,
    "pixel_size_m": [
      0.43283582089552236,
      0.4329427083333333
    ],
    "row_direction": "north to south",
    "outside_coverage": "alpha=0; transparent, not valid imagery",
    "sha256": "7f4b89749d99d9e1b6f5c2f6917fc7379d18b15f2fd726a60401126d72eaa987",
    "absolute_geolocation_accuracy": "Not independently established"
  },
  "plan_pixel_convention": "Original redacted map PNG / repo WebP pixel coordinates, x right, y down. Page7/8 1584x1790, page9 1584x1770.",
  "page7_to_ortho_pixel_matrix": [
    [
      1.290016350847684,
      0.025567961868638633,
      -61.445028774035016
    ],
    [
      -0.025567961868638633,
      1.290016350847684,
      111.76918605360437
    ]
  ],
  "page_links": {
    "8": {
      "to_page": 7,
      "matrix": [
        [
          0.9996817675234393,
          0.00023075870160705199,
          -55.31514621808218
        ],
        [
          -0.00023075870160705199,
          0.9996817675234393,
          738.509890920953
        ]
      ],
      "method": "SIFT descriptors, Lowe ratio 0.72; similarity RANSAC, 8px threshold; overlapping plan aerial imagery only",
      "candidate_matches": 660,
      "inlier_count": 424,
      "rms_target_page_px": 1.5265298744362434,
      "max_target_page_px": 8.126450605308355
    },
    "9": {
      "to_page": 7,
      "matrix": [
        [
          0.49947272146788785,
          0.0005313985602073355,
          316.88689473020827
        ],
        [
          -0.0005313985602073355,
          0.49947272146788785,
          1080.0313399840434
        ]
      ],
      "method": "SIFT descriptors, Lowe ratio 0.72; similarity RANSAC, 8px threshold; overlapping plan aerial imagery only",
      "candidate_matches": 345,
      "inlier_count": 136,
      "rms_target_page_px": 2.2470577123127353,
      "max_target_page_px": 8.371880928107862
    }
  },
  "controls": [
    {
      "id": "house-north",
      "page": 7,
      "plan_px": [
        636,
        174
      ],
      "ortho_px": [
        759,
        326
      ],
      "role": "fit",
      "description": "Center of light-roof house south of highway; roof appearance changed",
      "predicted_ortho_px": [
        763.4541957302351,
        319.9708073526472
      ],
      "residual_m": 3.2450847620919374
    },
    {
      "id": "shed-west",
      "page": 7,
      "plan_px": [
        504,
        440
      ],
      "ortho_px": [
        594,
        670
      ],
      "role": "fit",
      "description": "Center of isolated light-roof shed west of northern pond",
      "predicted_ortho_px": [
        599.9731152753988,
        666.4901276447915
      ],
      "residual_m": 2.9988805863937715
    },
    {
      "id": "pond-gate",
      "page": 7,
      "plan_px": [
        632,
        309
      ],
      "ortho_px": [
        749,
        512
      ],
      "role": "check",
      "description": "Small light-roof structure at drive turn west of northern pond",
      "predicted_ortho_px": [
        761.7458051791107,
        494.2252865645591
      ],
      "residual_m": 9.46864391850014
    },
    {
      "id": "drive-elbow",
      "page": 7,
      "plan_px": [
        740,
        507
      ],
      "ortho_px": [
        907,
        752
      ],
      "role": "fit",
      "description": "Driveway eastward elbow south of northern pond",
      "predicted_ortho_px": [
        906.130027520651,
        746.8871841505876
      ],
      "residual_m": 2.2453564378562505
    },
    {
      "id": "north-pasture-tree",
      "page": 7,
      "plan_px": [
        827,
        794
      ],
      "ortho_px": [
        1043,
        1104
      ],
      "role": "fit",
      "description": "Isolated rounded tree crown west/southwest of northern sinkhole marker; crown approximate",
      "predicted_ortho_px": [
        1025.6994551006987,
        1114.8974641613015
      ],
      "residual_m": 8.850643105568475
    },
    {
      "id": "pond-south",
      "page": 9,
      "plan_px": [
        891,
        446
      ],
      "ortho_px": [
        954,
        1762
      ],
      "role": "fit",
      "description": "Southern tip of central triangular pond waterline; shoreline seasonally variable",
      "predicted_ortho_px": [
        955.043950542993,
        1772.300033295374
      ],
      "residual_m": 4.4821590820617825
    },
    {
      "id": "pond-northeast",
      "page": 9,
      "plan_px": [
        1006,
        229
      ],
      "ortho_px": [
        1009,
        1652
      ],
      "role": "check",
      "description": "Northeast corner of central pond waterline; obscured by plan symbols",
      "predicted_ortho_px": [
        1026.2201508002818,
        1630.936369091836
      ],
      "residual_m": 11.77782215845357
    },
    {
      "id": "south-upper-tree",
      "page": 8,
      "plan_px": [
        652,
        1135
      ],
      "ortho_px": [
        756,
        2515
      ],
      "role": "fit",
      "description": "Upper isolated small tree in southwest pasture clearing",
      "predicted_ortho_px": [
        756.2471438206101,
        2512.710136752921
      ],
      "residual_m": 0.9971342243611212
    },
    {
      "id": "south-middle-tree",
      "page": 8,
      "plan_px": [
        610,
        1167
      ],
      "ortho_px": [
        707,
        2558
      ],
      "role": "check",
      "description": "Middle isolated small tree in southwest pasture clearing",
      "predicted_ortho_px": [
        702.9113871903271,
        2555.063349704018
      ],
      "residual_m": 2.1790577434257288
    },
    {
      "id": "south-lower-tree",
      "page": 8,
      "plan_px": [
        650,
        1204
      ],
      "ortho_px": [
        749,
        2606
      ],
      "role": "fit",
      "description": "Lower isolated tree in southwest pasture clearing; crown approximate",
      "predicted_ortho_px": [
        755.4521120081283,
        2601.744246643214
      ],
      "residual_m": 3.3457434049118935
    }
  ],
  "fit": {
    "count": 7,
    "rms_m": 4.394434701652155,
    "max_m": 8.850643105568475,
    "median_m": 3.2450847620919374
  },
  "withheld_checks": {
    "count": 3,
    "rms_m": 8.815149934453625,
    "max_m": 11.77782215845357,
    "median_m": 9.46864391850014
  },
  "leave_one_fit_control_out": {
    "count": 7,
    "rms_m": 5.7266254428929555,
    "max_m": 10.606558912664307,
    "median_m": 5.116161305636741
  },
  "positional_uncertainty_allowance_m": 20,
  "uncertainty_note": "Illustrative conservative allowance, NOT a 95% error bound or survey accuracy; no absolute accuracy assertion.",
  "independent_sinkhole_diagnostics": [
    {
      "name": "middle sinkhole 3 (circle on north infrastructure map)",
      "page": 7,
      "plan_px": [
        893,
        775
      ],
      "lonlat": [
        -85.4494,
        36.4091
      ],
      "difference_m": 17.2472209374043,
      "used_in_fit": false,
      "note": "Independent rounded report point vs plan symbol; not surveyed control."
    },
    {
      "name": "south sinkhole 2",
      "page": 8,
      "plan_px": [
        947,
        1006
      ],
      "lonlat": [
        -85.4494,
        36.4039
      ],
      "difference_m": 52.43263664946517,
      "used_in_fit": false,
      "note": "Independent rounded report point vs plan symbol; not surveyed control."
    }
  ],
  "feature_counts": {
    "fence": 10,
    "pipeline": 1,
    "waterer": 3,
    "spring": 1,
    "heavy-use": 3
  },
  "fence": {
    "traced_horizontal_length_ft": 7285.9,
    "scheduled_total_ft": 8303,
    "complete_scheduled_network": false,
    "note": "Only visually distinguishable black fence linework traced. No extension or rescaling to scheduled total. Western woodland fence partly obscured/overprinted (30 m allowance); yellow land-unit bays and unresolved segments omitted."
  },
  "pipeline": {
    "traced_horizontal_length_ft": 495.8,
    "profile_reference_ft": 565,
    "design_allowance_ft": 600,
    "difference_from_profile_ft": -69.2,
    "difference_from_profile_percent": -12.25,
    "note": "Plan trace and later oblique profile are distinct sources; horizontal vs terrain-following measurement and registration/endpoint uncertainty also differ. Route not stretched to match."
  },
  "heavy_use": {
    "area_total_sqft": 720,
    "allocation_sqft": [
      240,
      240,
      240
    ],
    "dimensions_ft": [
      12,
      20
    ],
    "heading_deg": [
      0,
      210,
      30
    ],
    "note": "Three illustrative 12 x 20 ft rectangles, 240 sq ft each, centered on mapped facility symbols. Total 720 sq ft is scheduled; equal allocation, dimensions, orientation and footprints are NOT source-site dimensions. Small shaded boxes are map symbols and are not reliably distinguishable as scaled pad boundaries. Ramp rectangles are conceptual surface areas, not engineered slopes."
  },
  "validation": [
    {
      "id": "fence-woodland-west",
      "valid_geometry": true,
      "inside_parcel": false,
      "inside_parcel_with_20m_tolerance": true,
      "sampled_ortho_coverage_fraction": 1.0,
      "coverage_sample_count": 100
    },
    {
      "id": "fence-north-spine",
      "valid_geometry": true,
      "inside_parcel": true,
      "inside_parcel_with_20m_tolerance": true,
      "sampled_ortho_coverage_fraction": 1.0,
      "coverage_sample_count": 100
    },
    {
      "id": "fence-north-divider",
      "valid_geometry": true,
      "inside_parcel": false,
      "inside_parcel_with_20m_tolerance": true,
      "sampled_ortho_coverage_fraction": 1.0,
      "coverage_sample_count": 100
    },
    {
      "id": "fence-water-spine",
      "valid_geometry": true,
      "inside_parcel": true,
      "inside_parcel_with_20m_tolerance": true,
      "sampled_ortho_coverage_fraction": 1.0,
      "coverage_sample_count": 100
    },
    {
      "id": "fence-pond-northeast-divider",
      "valid_geometry": true,
      "inside_parcel": true,
      "inside_parcel_with_20m_tolerance": true,
      "sampled_ortho_coverage_fraction": 1.0,
      "coverage_sample_count": 100
    },
    {
      "id": "fence-pond-south-divider",
      "valid_geometry": true,
      "inside_parcel": true,
      "inside_parcel_with_20m_tolerance": true,
      "sampled_ortho_coverage_fraction": 1.0,
      "coverage_sample_count": 100
    },
    {
      "id": "fence-pond-south-access",
      "valid_geometry": true,
      "inside_parcel": true,
      "inside_parcel_with_20m_tolerance": true,
      "sampled_ortho_coverage_fraction": 1.0,
      "coverage_sample_count": 100
    },
    {
      "id": "fence-woodland-east",
      "valid_geometry": true,
      "inside_parcel": true,
      "inside_parcel_with_20m_tolerance": true,
      "sampled_ortho_coverage_fraction": 1.0,
      "coverage_sample_count": 100
    },
    {
      "id": "fence-woodland-south",
      "valid_geometry": true,
      "inside_parcel": true,
      "inside_parcel_with_20m_tolerance": true,
      "sampled_ortho_coverage_fraction": 1.0,
      "coverage_sample_count": 100
    },
    {
      "id": "fence-south-spine",
      "valid_geometry": true,
      "inside_parcel": true,
      "inside_parcel_with_20m_tolerance": true,
      "sampled_ortho_coverage_fraction": 1.0,
      "coverage_sample_count": 100
    },
    {
      "id": "pipeline-pond-to-waterer",
      "valid_geometry": true,
      "inside_parcel": true,
      "inside_parcel_with_20m_tolerance": true,
      "sampled_ortho_coverage_fraction": 1.0,
      "coverage_sample_count": 100
    },
    {
      "id": "waterer-1",
      "valid_geometry": true,
      "inside_parcel": true,
      "inside_parcel_with_20m_tolerance": true,
      "sampled_ortho_coverage_fraction": 1.0,
      "coverage_sample_count": 1
    },
    {
      "id": "waterer-2",
      "valid_geometry": true,
      "inside_parcel": true,
      "inside_parcel_with_20m_tolerance": true,
      "sampled_ortho_coverage_fraction": 1.0,
      "coverage_sample_count": 1
    },
    {
      "id": "waterer-3",
      "valid_geometry": true,
      "inside_parcel": true,
      "inside_parcel_with_20m_tolerance": true,
      "sampled_ortho_coverage_fraction": 1.0,
      "coverage_sample_count": 1
    },
    {
      "id": "spring-1",
      "valid_geometry": true,
      "inside_parcel": true,
      "inside_parcel_with_20m_tolerance": true,
      "sampled_ortho_coverage_fraction": 1.0,
      "coverage_sample_count": 1
    },
    {
      "id": "heavy-use-1",
      "valid_geometry": true,
      "inside_parcel": true,
      "inside_parcel_with_20m_tolerance": true,
      "sampled_ortho_coverage_fraction": 1.0,
      "coverage_sample_count": 100
    },
    {
      "id": "heavy-use-2",
      "valid_geometry": true,
      "inside_parcel": true,
      "inside_parcel_with_20m_tolerance": true,
      "sampled_ortho_coverage_fraction": 1.0,
      "coverage_sample_count": 100
    },
    {
      "id": "heavy-use-3",
      "valid_geometry": true,
      "inside_parcel": true,
      "inside_parcel_with_20m_tolerance": true,
      "sampled_ortho_coverage_fraction": 1.0,
      "coverage_sample_count": 100
    }
  ],
  "limitations": [
    "Approximate proposed-plan visualization only, not surveyed, field-staked, as-built, installed or funding-approved.",
    "Absolute ortho geolocation accuracy is not independently established. Manual controls use changing roofs, tree crowns and pond shores. Reported residuals do not include all temporal/source-image/geolocation uncertainty.",
    "Only visible black tick-marked fence linework is traced. Yellow practice-unit outlines are not assumed to be fences or legal boundaries. Western woodland fence is partly overprinted/obscured and has lower confidence; its straight segments cross yellow practice-unit bays. Unresolved fence segments omitted. Traces do not purport to reconstruct the entire scheduled 8,303 ft.",
    "Pipeline traced from mapped cyan route, not stretched to reproduce the later 565 ft oblique profile or 600 ft design allowance.",
    "Pad dimensions/allocation/heading are illustrative assumptions, not construction dimensions.",
    "Capture alpha outside coverage stays transparent; raster extent alone does not establish actual drone coverage.",
    "Rounded report middle/south sinkhole coordinates used only as independent diagnostics, never as calibration control. The circle on the north infrastructure page corresponds spatially to the MIDDLE report point, not the northern report point. Northern report location is near the small north pond/planting symbol, not a clearly distinguishable sinkhole circle. South report point disagrees with the mapped circle by roughly 50 m; source coordinate/marker discrepancy is unresolved."
  ],
  "schema": {
    "kind": "fence|pipeline|heavy-use|waterer|spring",
    "practiceId": "same as kind",
    "practiceCode": "NRCS numeric practice code as string",
    "coordinates": "WGS84 [longitude, latitude], no height; height from capture DTM",
    "geometry": {
      "fence": "LineString",
      "pipeline": "LineString",
      "heavy-use": "Polygon",
      "waterer": "Point",
      "spring": "Point"
    }
  }
}