AIS Events

{
    "vessel_a": {
        "mmsi": 273456730,
        "imo": 9084401,
        "name": "AZOV",
        "flag": "Russia"
    },
    "vessel_b": {
        "mmsi": 273439180,
        "imo": 8930744,
        "name": "ZAPRAVSHCHIK 05",
        "flag": "Russia"
    },
    "min_distance_m": 406,
    "avg_distance_m": 407.6000000000000227373675443232059478759765625,
    "distance_consistency_m": 0.90000000000000002220446049250313080847263336181640625,
    "duration_minutes": 57,
    "overlap_duration_s": 3421,
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    "speed_a_std": 0.059999999999999997779553950749686919152736663818359375,
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    "speed_b_std": 0.0899999999999999966693309261245303787291049957275390625,
    "speed_summary": {
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            "max_sog": 0.200000000000000011102230246251565404236316680908203125
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            "max_sog": 0.200000000000000011102230246251565404236316680908203125
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    },
    "time_window": {
        "start": "2026-07-19T03:37:54+00:00",
        "end": "2026-07-19T04:34:55+00:00"
    },
    "points_count": {
        "vessel_a": 17,
        "vessel_b": 17
    },
    "zone_id": "russia_sakhalin_south",
    "zone_name": "Sakhalin South Approach",
    "score": {
        "value": 60,
        "components": {
            "distance_tightness": {
                "score": 5,
                "max": 25,
                "detail": "Min distance 406m, avg 408m"
            },
            "duration": {
                "score": 10,
                "max": 25,
                "detail": "Duration 57 minutes"
            },
            "speed_stability": {
                "score": 20,
                "max": 20,
                "detail": "both nearly stationary; very stable speeds"
            },
            "distance_consistency": {
                "score": 15,
                "max": 15,
                "detail": "Distance variance \u00b11m"
            },
            "isolation": {
                "score": 5,
                "max": 10,
                "detail": "Isolation data not available"
            },
            "context": {
                "score": 5,
                "max": 5,
                "detail": "In monitored zone: Sakhalin South Approach"
            }
        },
        "summary": "Moderate-confidence STS candidate. Two tankers (AZOV and ZAPRAVSHCHIK 05) maintained close proximity (min 406m, avg 408m) for 57 minutes. Both vessels were slow-moving (avg speeds 0.0 and 0.1 knots). The stable separation distance suggests deliberate parallel positioning typical of cargo transfer. Event occurred in Sakhalin South Approach, a known STS activity area."
    }
}

{
    "vessel_a": {
        "mmsi": 273456730,
        "imo": 9084401,
        "name": "AZOV",
        "flag": "Russia"
    },
    "vessel_b": {
        "mmsi": 273439180,
        "imo": 8930744,
        "name": "ZAPRAVSHCHIK 05",
        "flag": "Russia"
    },
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    "avg_distance_m": 408.19999999999998863131622783839702606201171875,
    "distance_consistency_m": 0.6999999999999999555910790149937383830547332763671875,
    "duration_minutes": 168.900000000000005684341886080801486968994140625,
    "overlap_duration_s": 10132,
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    "speed_b_std": 0.070000000000000006661338147750939242541790008544921875,
    "speed_summary": {
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            "max_sog": 0.1000000000000000055511151231257827021181583404541015625
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            "max_sog": 0.200000000000000011102230246251565404236316680908203125
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    },
    "time_window": {
        "start": "2026-07-19T00:38:33+00:00",
        "end": "2026-07-19T03:27:25+00:00"
    },
    "points_count": {
        "vessel_a": 39,
        "vessel_b": 39
    },
    "zone_id": "russia_sakhalin_south",
    "zone_name": "Sakhalin South Approach",
    "score": {
        "value": 75,
        "components": {
            "distance_tightness": {
                "score": 5,
                "max": 25,
                "detail": "Min distance 407m, avg 408m"
            },
            "duration": {
                "score": 25,
                "max": 25,
                "detail": "Duration 169 minutes"
            },
            "speed_stability": {
                "score": 20,
                "max": 20,
                "detail": "both nearly stationary; very stable speeds"
            },
            "distance_consistency": {
                "score": 15,
                "max": 15,
                "detail": "Distance variance \u00b11m"
            },
            "isolation": {
                "score": 5,
                "max": 10,
                "detail": "Isolation data not available"
            },
            "context": {
                "score": 5,
                "max": 5,
                "detail": "In monitored zone: Sakhalin South Approach"
            }
        },
        "summary": "Moderate-confidence STS candidate. Two tankers (AZOV and ZAPRAVSHCHIK 05) maintained close proximity (min 407m, avg 408m) for 169 minutes. Both vessels were slow-moving (avg speeds 0.0 and 0.1 knots). The stable separation distance suggests deliberate parallel positioning typical of cargo transfer. Event occurred in Sakhalin South Approach, a known STS activity area."
    }
}

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{
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{
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        "mmsi": 273439180,
        "imo": 8930744,
        "name": "ZAPRAVSHCHIK 05",
        "flag": "Russia"
    },
    "vessel_b": {
        "mmsi": 273456730,
        "imo": 9084401,
        "name": "AZOV",
        "flag": "Russia"
    },
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    "time_window": {
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        "end": "2026-07-19T04:37:43+00:00"
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    "points_count": {
        "vessel_a": 33,
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    "zone_id": "russia_sakhalin_south",
    "zone_name": "Sakhalin South Approach",
    "score": {
        "value": 75,
        "components": {
            "distance_tightness": {
                "score": 5,
                "max": 25,
                "detail": "Min distance 407m, avg 408m"
            },
            "duration": {
                "score": 25,
                "max": 25,
                "detail": "Duration 381 minutes"
            },
            "speed_stability": {
                "score": 20,
                "max": 20,
                "detail": "both nearly stationary; very stable speeds"
            },
            "distance_consistency": {
                "score": 15,
                "max": 15,
                "detail": "Distance variance \u00b11m"
            },
            "isolation": {
                "score": 5,
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                "detail": "Isolation data not available"
            },
            "context": {
                "score": 5,
                "max": 5,
                "detail": "In monitored zone: Sakhalin South Approach"
            }
        },
        "summary": "Moderate-confidence STS candidate. Two tankers (ZAPRAVSHCHIK 05 and AZOV) maintained close proximity (min 407m, avg 408m) for 381 minutes. Both vessels were slow-moving (avg speeds 0.1 and 0.0 knots). The stable separation distance suggests deliberate parallel positioning typical of cargo transfer. Event occurred in Sakhalin South Approach, a known STS activity area."
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