improve the dynamic overlay

modules/overlay/dynamic/DynamicBillboard.js

     /**
      * set the location
      */
-    this._samplePosition.forwardExtrapolationType =
+    this._sampledPosition.forwardExtrapolationType =
       Cesium.ExtrapolationType.HOLD
     this._startTime = Cesium.JulianDate.now()
-    this._samplePosition.addSample(
+    this._sampledPosition.addSample(
       this._startTime,
       Transform.transformWGS84ToCartesian(this._posistion)
     )
-    this._delegate.position = this._samplePosition
+    this._delegate.position = this._sampledPosition
     this._cache.push(this._startTime)
     /**
      *  initialize the Overlay parameter

modules/overlay/dynamic/DynamicModel.js

     /**
      * set the location
      */
-    this._samplePosition.forwardExtrapolationType =
+    this._sampledPosition.forwardExtrapolationType =
       Cesium.ExtrapolationType.HOLD
     this._startTime = Cesium.JulianDate.now()
-    this._samplePosition.addSample(
+    this._sampledPosition.addSample(
       this._startTime,
       Transform.transformWGS84ToCartesian(this._posistion)
     )
-    this._delegate.position = this._samplePosition
+    this._delegate.position = this._sampledPosition
     this._delegate.orientation = new Cesium.VelocityOrientationProperty(
-      this._samplePosition
+      this._sampledPosition
     )
     this._cache.push(this._startTime)
     /**

modules/overlay/dynamic/DynamicOverlay.js

     super()
     this._startTime = undefined
     this._lastTime = undefined
-    this._samplePosition = new Cesium.SampledPositionProperty()
+    this._sampledPosition = new Cesium.SampledPositionProperty()
     this._cache = []
     this._maxCacheSize = 10
     this._state = State.INITIALIZED
 
   get position() {
     return Transform.transformCartesianToWGS84(
-      this._samplePosition.getValue(Cesium.JulianDate.now())
+      this._sampledPosition.getValue(Cesium.JulianDate.now())
     )
   }
 
         -0.2,
         new Cesium.JulianDate()
       )
-      this._samplePosition.removeSamples(
+      this._sampledPosition.removeSamples(
         new Cesium.TimeInterval({
           start: start,
           stop: stop
       interval,
       new Cesium.JulianDate()
     )
-    this._samplePosition.addSample(
+    this._sampledPosition.addSample(
       time,
       Transform.transformWGS84ToCartesian(Parse.parsePosition(position))
     )
   }
 }
 
-Overlay.registerType('dynamic-model')
-
 export default DynamicOverlay