diff --git a/client/src/components/overlay/StationOverlay.tsx b/client/src/components/overlay/StationOverlay.tsx
index e462578..e89faed 100644
--- a/client/src/components/overlay/StationOverlay.tsx
+++ b/client/src/components/overlay/StationOverlay.tsx
@@ -114,6 +114,7 @@ export default function StationOverlay({ currentFrame, currentTime, fps, visible
   // 현재 상태 ref
   const currentDroneFrameRef = useRef<DroneFrameBasic | null>(null);
   const currentFrameNumRef = useRef<number>(0);       // RAF에서 Map 조회용
+  const currentFrameIdxRef = useRef<number>(0);       // smoothFrame용 배열 인덱스
   const currentTimeSecRef = useRef<number>(0);        // 마지막으로 알려진 재생 시간
   const timeUpdateWallRef = useRef<number>(performance.now()); // currentTime 갱신된 시각
   const paramsRef = useRef<CameraParams>(DEFAULT_CAMERA_PARAMS);
@@ -298,13 +299,14 @@ export default function StationOverlay({ currentFrame, currentTime, fps, visible
     if (!visible || !droneFramesLoaded) return;
     const frames = allDroneFramesRef.current;
     if (!frames.length) return;
-    let best = frames[0], bestD = Math.abs((best.frame ?? 0) / VIDEO_FPS - currentTime);
-    for (const f of frames) {
-      const d = Math.abs(f.frame / VIDEO_FPS - currentTime);
-      if (d < bestD) { bestD = d; best = f; }
+    let best = frames[0], bestIdx = 0, bestD = Math.abs((best.frame ?? 0) / VIDEO_FPS - currentTime);
+    for (let i = 0; i < frames.length; i++) {
+      const d = Math.abs(frames[i].frame / VIDEO_FPS - currentTime);
+      if (d < bestD) { bestD = d; best = frames[i]; bestIdx = i; }
       if (bestD < 1 / VIDEO_FPS / 2) break;
     }
     currentFrameNumRef.current = best.frame;
+    currentFrameIdxRef.current = bestIdx;
     currentTimeSecRef.current = currentTime;
     timeUpdateWallRef.current = performance.now();
     if (currentDroneFrameRef.current?.frame !== best.frame) {
@@ -315,10 +317,14 @@ export default function StationOverlay({ currentFrame, currentTime, fps, visible
 
   // 중심선 + 나침반 캐시 빌드 (per-frame, 텍스트 계산 없음)
   useEffect(() => {
-    const drone = currentDroneFrameRef.current;
-    if (!drone || !visible) { renderCacheRef.current = null; return; }
+    if (!currentDroneFrameRef.current || !visible) { renderCacheRef.current = null; return; }
 
     const t0 = performance.now();
+    // 중심선도 smoothFrame 적용 (텍스트와 동일한 스무딩)
+    const frames = allDroneFramesRef.current;
+    const drone = frames.length
+      ? smoothFrame(frames, currentFrameIdxRef.current, smoothHalfRef.current)
+      : currentDroneFrameRef.current;
     const params = paramsRef.current;
     const worldOrigin = worldOriginRef.current;
     const allCL = allCenterlinePointsRef.current;
@@ -426,28 +432,12 @@ export default function StationOverlay({ currentFrame, currentTime, fps, visible
       const elapsed = (performance.now() - timeUpdateWallRef.current) / 1000;
       const estTime = currentTimeSecRef.current + elapsed;
       const frac = Math.min(0.999, (estTime * VIDEO_FPS) - frameNum);  // 0~0.999
-      const mapSize = labelMapRef.current.size;
       const labelsA = labelMapRef.current.get(frameNum);
       const labelsB = labelMapRef.current.get(frameNum + 1);
 
       // 두 프레임 사이 픽셀 좌표 보간
       const interpY = (a: number, b: number | undefined) => b !== undefined ? a + (b - a) * frac : a;
 
-      // 디버그 표시 (좌하단)
-      ctx.font = '11px monospace';
-      ctx.textAlign = 'left';
-      ctx.textBaseline = 'top';
-      ctx.fillStyle = 'rgba(0,0,0,0.6)';
-      ctx.fillRect(6, H - 54, 300, 48);
-      ctx.fillStyle = '#0f0';
-      ctx.fillText(`frame: ${frameNum}  frac: ${frac.toFixed(2)}  mapSize: ${mapSize}`, 10, H - 50);
-      const firstSt = labelsA?.stationLabels[0];
-      const firstStB = labelsB?.stationLabels[0];
-      const dispY = firstSt ? interpY(firstSt.sy, firstStB?.sy) * H : 0;
-      ctx.fillText(`labels: ${labelsA?.stationLabels.length ?? '-'}  firstY: ${firstSt ? dispY.toFixed(1) : '-'}px`, 10, H - 36);
-      ctx.fillText(`smooth: ±${smoothHalfRef.current}fr  interp: ${frac.toFixed(2)}`, 10, H - 22);
-      ctx.textBaseline = 'alphabetic';
-
       if (labelsA) {
         const α = emaAlphaRef.current;