{
  "type": "FeatureCollection",
  "_meta": {
    "version": "1.0",
    "disclaimer": "Synthetic demo data inspired by real Baltic geography, MMSI/OUI conventions, and infrastructure. Not real observations.",
    "policy": "Real infrastructure names retained per 'looking-real all the way' decision; alignments are SYNTHETIC plausibility-checked approximations."
  },
  "features": [
    {"type":"Feature","properties":{"featureId":"estlink-1","kind":"cable","name":"Estlink 1","note":"HVDC submarine cable, synthetic alignment Helsinki-Tallinn"},
      "geometry":{"type":"LineString","coordinates":[[24.9100,60.2400],[24.8500,59.8500],[24.8000,59.4800]]}},
    {"type":"Feature","properties":{"featureId":"estlink-1-buffer","kind":"cable_buffer","name":"Estlink 1 500m buffer","parent":"estlink-1"},
      "geometry":{"type":"Polygon","coordinates":[[[24.9100,60.2400],[24.9150,60.2400],[24.8050,59.4800],[24.7950,59.4800],[24.9100,60.2400]]]}},
    {"type":"Feature","properties":{"featureId":"estlink-2","kind":"cable","name":"Estlink 2","note":"HVDC submarine cable, synthetic alignment parallel to Estlink 1"},
      "geometry":{"type":"LineString","coordinates":[[24.9300,60.2400],[24.8700,59.8500],[24.8200,59.4800]]}},
    {"type":"Feature","properties":{"featureId":"estlink-2-buffer","kind":"cable_buffer","name":"Estlink 2 500m buffer","parent":"estlink-2"},
      "geometry":{"type":"Polygon","coordinates":[[[24.9300,60.2400],[24.9350,60.2400],[24.8250,59.4800],[24.8150,59.4800],[24.9300,60.2400]]]}},
    {"type":"Feature","properties":{"featureId":"balticconnector","kind":"pipeline","name":"BalticConnector","note":"Natural gas pipeline, synthetic alignment Inkoo-Paldiski"},
      "geometry":{"type":"LineString","coordinates":[[24.0050,59.9400],[24.2000,59.7000],[24.4000,59.4000]]}},
    {"type":"Feature","properties":{"featureId":"balticconnector-buffer","kind":"pipeline_buffer","name":"BalticConnector 500m buffer","parent":"balticconnector"},
      "geometry":{"type":"Polygon","coordinates":[[[24.0050,59.9400],[24.0100,59.9400],[24.4050,59.4000],[24.3950,59.4000],[24.0050,59.9400]]]}},
    {"type":"Feature","properties":{"featureId":"c-lion1","kind":"cable","name":"C-Lion1","note":"Data cable synthetic alignment Helsinki-Rostock"},
      "geometry":{"type":"LineString","coordinates":[[25.0000,60.1500],[24.0000,59.5000],[20.0000,57.0000]]}},
    {"type":"Feature","properties":{"featureId":"c-lion2","kind":"cable","name":"C-Lion2 (placeholder)","note":"Data cable placeholder synthetic"},
      "geometry":{"type":"LineString","coordinates":[[25.1000,60.1500],[24.1000,59.5000],[20.1000,57.0000]]}},
    {"type":"Feature","properties":{"featureId":"cable-pipeline-junction","kind":"junction","name":"Cable-and-pipeline JUNCTION polygon","note":"Overlap zone where BalticConnector and Estlink corridors cross within ~1.5 NM. Primary loitering target."},
      "geometry":{"type":"Polygon","coordinates":[[[24.4980,59.9210],[24.6420,59.9210],[24.6420,59.8475],[24.4980,59.8475],[24.4980,59.9210]]]}},
    {"type":"Feature","properties":{"featureId":"finnish-eez-gof","kind":"eez","name":"Finnish EEZ (Gulf of Finland clip)"},
      "geometry":{"type":"Polygon","coordinates":[[[22.0,59.5],[28.0,59.5],[28.0,60.6],[22.0,60.6],[22.0,59.5]]]}},
    {"type":"Feature","properties":{"featureId":"shipping-lane-eb","kind":"lane","name":"GoF eastbound TSS centerline"},
      "geometry":{"type":"LineString","coordinates":[[22.5,59.65],[24.0,59.75],[25.5,59.85],[27.0,59.95]]}},
    {"type":"Feature","properties":{"featureId":"shipping-lane-wb","kind":"lane","name":"GoF westbound TSS centerline"},
      "geometry":{"type":"LineString","coordinates":[[27.0,60.05],[25.5,59.95],[24.0,59.85],[22.5,59.75]]}},
    {"type":"Feature","properties":{"featureId":"port-helsinki","kind":"port","name":"Helsinki"},"geometry":{"type":"Point","coordinates":[24.9500,60.1700]}},
    {"type":"Feature","properties":{"featureId":"port-hanko","kind":"port","name":"Hanko"},"geometry":{"type":"Point","coordinates":[22.9700,59.8230]}},
    {"type":"Feature","properties":{"featureId":"port-kotka","kind":"port","name":"Kotka"},"geometry":{"type":"Point","coordinates":[26.9450,60.4625]}},
    {"type":"Feature","properties":{"featureId":"port-kilpilahti","kind":"port","name":"Inkoo / Kilpilahti"},"geometry":{"type":"Point","coordinates":[25.5500,60.3000]}},
    {"type":"Feature","properties":{"featureId":"port-porvoo","kind":"port","name":"Porvoo"},"geometry":{"type":"Point","coordinates":[25.6700,60.3950]}},
    {"type":"Feature","properties":{"featureId":"port-uto","kind":"port","name":"Utö"},"geometry":{"type":"Point","coordinates":[21.3700,59.7790]}},
    {"type":"Feature","properties":{"featureId":"site-kilpilahti","kind":"industrial_site","name":"Kilpilahti petrochemical complex","note":"Recon target polygon in S5"},
      "geometry":{"type":"Polygon","coordinates":[[[26.0050,60.1500],[26.0150,60.1500],[26.0150,60.1430],[26.0050,60.1430],[26.0050,60.1500]]]}},
    {"type":"Feature","properties":{"featureId":"site-vuosaari","kind":"industrial_site","name":"Helsinki Vuosaari container port"},
      "geometry":{"type":"Polygon","coordinates":[[[25.180,60.205],[25.205,60.205],[25.205,60.215],[25.180,60.215],[25.180,60.205]]]}},
    {"type":"Feature","properties":{"featureId":"site-mussalo","kind":"industrial_site","name":"Kotka Mussalo container port"},
      "geometry":{"type":"Polygon","coordinates":[[[26.870,60.430],[26.895,60.430],[26.895,60.440],[26.870,60.440],[26.870,60.430]]]}}
  ]
}