Phase 2.2: performance optimizations, debug tools, app close fix

backend/app/services/los_service.py

@@ -98,6 +98,59 @@ class LineOfSightService:
             "profile": profile
         }
 
+    def check_line_of_sight_sync(
+        self,
+        tx_lat: float, tx_lon: float, tx_height: float,
+        rx_lat: float, rx_lon: float, rx_height: float = 1.5,
+        num_samples: int = 50
+    ) -> dict:
+        """
+        Sync LOS check - terrain tiles must be pre-loaded into memory.
+        Returns dict with has_los, clearance, blocked_at (no profile for speed).
+        """
+        profile = self.terrain.get_elevation_profile_sync(
+            tx_lat, tx_lon, rx_lat, rx_lon, num_samples
+        )
+
+        if not profile:
+            return {"has_los": True, "clearance": 0, "blocked_at": None}
+
+        tx_ground = profile[0]["elevation"]
+        rx_ground = profile[-1]["elevation"]
+
+        tx_total = tx_ground + tx_height
+        rx_total = rx_ground + rx_height
+
+        total_distance = profile[-1]["distance"]
+
+        min_clearance = float('inf')
+        blocked_at = None
+
+        for point in profile:
+            d = point["distance"]
+            terrain_elev = point["elevation"]
+
+            if total_distance == 0:
+                los_height = tx_total
+            else:
+                los_height = tx_total + (rx_total - tx_total) * (d / total_distance)
+
+            effective_radius = self.K_FACTOR * self.EARTH_RADIUS
+            curvature = (d * (total_distance - d)) / (2 * effective_radius)
+            los_height_corrected = los_height - curvature
+            clearance = los_height_corrected - terrain_elev
+
+            if clearance < min_clearance:
+                min_clearance = clearance
+                if clearance <= 0:
+                    blocked_at = d
+
+        return {
+            "has_los": min_clearance > 0,
+            "clearance": min_clearance,
+            "blocked_at": blocked_at,
+        }
+
     async def calculate_fresnel_clearance(
         self,
         tx_lat: float, tx_lon: float, tx_height: float,