diff --git a/app/src/main/java/com/casic/detector/extensions/AMapLocation.kt b/app/src/main/java/com/casic/detector/extensions/AMapLocation.kt
index 08faa81..cc5d228 100644
--- a/app/src/main/java/com/casic/detector/extensions/AMapLocation.kt
+++ b/app/src/main/java/com/casic/detector/extensions/AMapLocation.kt
@@ -4,6 +4,7 @@
 import com.amap.api.maps.AMapUtils
 import com.amap.api.maps.model.LatLng
 import kotlin.math.acos
+import kotlin.math.pow
 
 /**
  * 计算两个经纬度之间连线的方位角，因为距离很近（一般是5米内），球面近似为平面
@@ -11,41 +12,41 @@
  * 手机坐标轴Y轴反置，所以右下角才是第一象限
  * */
 fun AMapLocation.calculateAngle(target: LatLng): Int {
-    //构造直角辅助点C
-    val auxiliaryPoint = LatLng(target.latitude, this.longitude)
+    //构造辅助点C
+    val auxiliaryPoint = LatLng(this.latitude, target.longitude)
 
     //AB线段长度
-    val distance = AMapUtils.calculateLineDistance(
+    val AB = AMapUtils.calculateLineDistance(
         LatLng(this.latitude, this.longitude), target
     )
 
     //AC线段长度
-    val auxiliaryDistance = AMapUtils.calculateLineDistance(
+    val AC = AMapUtils.calculateLineDistance(
         auxiliaryPoint, target
     )
 
-    //求∠A的余弦值
-    val cosine = auxiliaryDistance / distance
+    //BC线段长度
+    val BC = AMapUtils.calculateLineDistance(
+        auxiliaryPoint, target
+    )
+
+    //余弦定理求∠BAC的余弦值
+    val cosine = (AB.pow(2) + AC.pow(2) - BC.pow(2)) / (2 * AB * AC)
 
     //反余弦得弧度
     val radian = acos(cosine)
 
     //弧度转角度，度=弧度×180°/π
     val angle = (radian * 180) / Math.PI
-
-    //判断方位
-    val direction = if (this.longitude < target.longitude && this.latitude < target.latitude) {
-        //东北方
-        angle.toInt()
-    } else if (this.longitude > target.longitude && this.latitude < target.latitude) {
-        //西北方
-        (angle + 90).toInt()
-    } else if (this.longitude > target.longitude && this.latitude > target.latitude) {
-        //西南方
-        (angle + 180).toInt()
-    } else {
-        //东南方
-        (angle + 270).toInt()
-    }
-    return direction
+    return angle.toInt()
+//    val direction = if (target.longitude > this.longitude && target.latitude > this.latitude) {
+//        angle.toInt()
+//    } else if (target.longitude > this.longitude && target.latitude < this.latitude) {
+//        (angle + 90).toInt()
+//    } else if (target.longitude < this.longitude && target.latitude < this.latitude) {
+//        (angle + 180).toInt()
+//    } else {
+//        (angle + 270).toInt()
+//    }
+//    return direction
 }
\ No newline at end of file

diff --git a/app/src/main/java/com/casic/detector/extensions/AMapLocation.kt b/app/src/main/java/com/casic/detector/extensions/AMapLocation.kt
index 08faa81..cc5d228 100644
--- a/app/src/main/java/com/casic/detector/extensions/AMapLocation.kt
+++ b/app/src/main/java/com/casic/detector/extensions/AMapLocation.kt
@@ -4,6 +4,7 @@
 import com.amap.api.maps.AMapUtils
 import com.amap.api.maps.model.LatLng
 import kotlin.math.acos
+import kotlin.math.pow
 
 /**
  * 计算两个经纬度之间连线的方位角，因为距离很近（一般是5米内），球面近似为平面
@@ -11,41 +12,41 @@
  * 手机坐标轴Y轴反置，所以右下角才是第一象限
  * */
 fun AMapLocation.calculateAngle(target: LatLng): Int {
-    //构造直角辅助点C
-    val auxiliaryPoint = LatLng(target.latitude, this.longitude)
+    //构造辅助点C
+    val auxiliaryPoint = LatLng(this.latitude, target.longitude)
 
     //AB线段长度
-    val distance = AMapUtils.calculateLineDistance(
+    val AB = AMapUtils.calculateLineDistance(
         LatLng(this.latitude, this.longitude), target
     )
 
     //AC线段长度
-    val auxiliaryDistance = AMapUtils.calculateLineDistance(
+    val AC = AMapUtils.calculateLineDistance(
         auxiliaryPoint, target
     )
 
-    //求∠A的余弦值
-    val cosine = auxiliaryDistance / distance
+    //BC线段长度
+    val BC = AMapUtils.calculateLineDistance(
+        auxiliaryPoint, target
+    )
+
+    //余弦定理求∠BAC的余弦值
+    val cosine = (AB.pow(2) + AC.pow(2) - BC.pow(2)) / (2 * AB * AC)
 
     //反余弦得弧度
     val radian = acos(cosine)
 
     //弧度转角度，度=弧度×180°/π
     val angle = (radian * 180) / Math.PI
-
-    //判断方位
-    val direction = if (this.longitude < target.longitude && this.latitude < target.latitude) {
-        //东北方
-        angle.toInt()
-    } else if (this.longitude > target.longitude && this.latitude < target.latitude) {
-        //西北方
-        (angle + 90).toInt()
-    } else if (this.longitude > target.longitude && this.latitude > target.latitude) {
-        //西南方
-        (angle + 180).toInt()
-    } else {
-        //东南方
-        (angle + 270).toInt()
-    }
-    return direction
+    return angle.toInt()
+//    val direction = if (target.longitude > this.longitude && target.latitude > this.latitude) {
+//        angle.toInt()
+//    } else if (target.longitude > this.longitude && target.latitude < this.latitude) {
+//        (angle + 90).toInt()
+//    } else if (target.longitude < this.longitude && target.latitude < this.latitude) {
+//        (angle + 180).toInt()
+//    } else {
+//        (angle + 270).toInt()
+//    }
+//    return direction
 }
\ No newline at end of file
diff --git a/app/src/main/java/com/casic/detector/view/MainActivity.kt b/app/src/main/java/com/casic/detector/view/MainActivity.kt
index 052bd42..4b0146b 100644
--- a/app/src/main/java/com/casic/detector/view/MainActivity.kt
+++ b/app/src/main/java/com/casic/detector/view/MainActivity.kt
@@ -1557,7 +1557,7 @@
             locationManager.getCurrentLocation(false, object : OnGetLocationListener {
                 override fun onAMapLocationGet(location: AMapLocation?) {
                     location?.apply {
-                        "[${longitude}, ${latitude}]".show(context)
+//                        "[${longitude}, ${latitude}]".show(context)
                         renderDataPoint(this)
                     }
                 }
@@ -1583,6 +1583,9 @@
                             LatLng(it.lat.toDouble(), it.lng.toDouble())
                         )
 
+//                        withContext(Dispatchers.Main){
+//                            "$angle".show(context)
+//                        }
                         val formatDistance = String.format("%.2f", distance)
                         dataPoints.add(RadarScanView.DataPoint(angle, formatDistance.toFloat()))
                     }