frontend/src/components/korea/FleetClusterLayer.tsx

@@ -180,7 +180,7 @@ export function FleetClusterLayer({ ships, analysisMap: analysisMapProp, onShipS
     ]);
 
     // 2. resolution별 분리 → 1h(primary) + 6h(secondary)
-    const history1h = history.filter(h => h.resolution === '1h');
+    const history1h = history.filter(h => h.resolution === '1h' || h.resolution === '1h-fb');
     const history6h = history.filter(h => h.resolution === '6h');
     // fallback: resolution 필드 없는 기존 데이터는 6h로 취급
     const effective1h = history1h.length > 0 ? history1h : history;

prediction/algorithms/polygon_builder.py

@@ -423,12 +423,16 @@ def build_all_group_snapshots(
             continue
 
         # ── 1h 활성 멤버 필터 ──
-        display_members_1h = [
+        active_members_1h = [
             gm for gm in gear_members
             if _get_time_bucket_age(gm.get('mmsi'), all_positions, now) <= DISPLAY_STALE_SEC
         ]
-        # fallback: 1h < 2이면 time_bucket 최신 2개 유지 (폴리곤 형태 보존)
-        if len(display_members_1h) < 2 and len(gear_members) >= 2:
+        active_count_1h = len(active_members_1h)
+
+        # fallback: 1h < 2이면 time_bucket 최신 2개 유지 (리플레이/일치율 추적용)
+        # 라이브 현황에서는 active_count_1h로 필터 (fallback 그룹 제외)
+        display_members_1h = active_members_1h
+        if active_count_1h < 2 and len(gear_members) >= 2:
             sorted_by_age = sorted(
                 gear_members,
                 key=lambda gm: _get_time_bucket_age(gm.get('mmsi'), all_positions, now),
@@ -443,7 +447,9 @@ def build_all_group_snapshots(
         display_members_6h = gear_members
 
         # ── resolution별 스냅샷 생성 ──
-        for resolution, members_for_snap in [('1h', display_members_1h), ('6h', display_members_6h)]:
+        # 1h-fb: fallback (실제 1h 활성 < 2) — 리플레이/일치율 추적용, 라이브 현황에서 제외
+        res_1h = '1h' if active_count_1h >= 2 else '1h-fb'
+        for resolution, members_for_snap in [(res_1h, display_members_1h), ('6h', display_members_6h)]:
             if len(members_for_snap) < 2:
                 continue
             # 6h: 최신 적재가 STALE_SEC(6h) 초과 시 스킵