{"type": "FeatureCollection", "_meta": {"__meta__": "synthetic", "disclaimer": "Synthetic demo data inspired by real Baltic geography, MMSI/OUI conventions, and infrastructure. Not real observations.", "dataset": "s3-loitering-critical-infra/sensors_used", "version": "1.0"}, "features": [{"type": "Feature", "geometry": {"type": "Point", "coordinates": [24.005, 59.94]}, "properties": {"sensorId": "MAC-INK-COAST-01", "kind": "mac", "subtype": "coastal", "site": "Inkoo headland", "range_km": 18, "notes": "near BalticConnector"}}, {"type": "Feature", "geometry": {"type": "Point", "coordinates": [24.38, 59.98]}, "properties": {"sensorId": "MAC-PRK-COAST-01", "kind": "mac", "subtype": "coastal", "site": "Porkkala lighthouse", "range_km": 20, "notes": "NE-bound traffic"}}, {"type": "Feature", "geometry": {"type": "Point", "coordinates": [24.385, 59.971]}, "properties": {"sensorId": "MAC-PRK-COAST-02", "kind": "mac", "subtype": "coastal", "site": "Porkkala south", "range_km": 15, "notes": "secondary"}}, {"type": "Feature", "geometry": {"type": "Point", "coordinates": [24.988, 60.145]}, "properties": {"sensorId": "MAC-HEL-COAST-01", "kind": "mac", "subtype": "coastal", "site": "Helsinki Suomenlinna", "range_km": 15, "notes": "low-elevation mast"}}, {"type": "Feature", "geometry": {"type": "Point", "coordinates": [24.9182, 60.1532]}, "properties": {"sensorId": "MAC-HEL-PORT-01", "kind": "mac", "subtype": "port", "site": "Helsinki West Harbour LJ-gate", "range_km": 1, "notes": "dense cluster"}}, {"type": "Feature", "geometry": {"type": "Point", "coordinates": [25.63, 60.205]}, "properties": {"sensorId": "MAC-PRV-COAST-01", "kind": "mac", "subtype": "coastal", "site": "Porvoo Em\u00e4salo", "range_km": 18, "notes": "south-tip island mast"}}, {"type": "Feature", "geometry": {"type": "Point", "coordinates": [24.95, 60.3]}, "properties": {"sensorId": "MAC-AIR-PLN-01", "kind": "mac", "subtype": "airborne", "site": "mobile (on RAD-PLN-01 Dornier 228-class)", "range_km": 30, "notes": "airborne; location_geom is start-of-day placeholder"}}, {"type": "Feature", "geometry": {"type": "Point", "coordinates": [24.42, 59.985]}, "properties": {"sensorId": "RAD-COAST-PRK-01", "kind": "radar", "subtype": "coastal", "site": "Porkkala coastal radar", "range_nm": 20}}, {"type": "Feature", "geometry": {"type": "Point", "coordinates": [25.0, 60.35]}, "properties": {"sensorId": "RAD-PLN-01", "kind": "radar", "subtype": "plane", "site": "mobile patrol aircraft (Dornier 228-class)", "sweep_s": 4}}]}