diff --git a/aman/sys/WeatherModel.py b/aman/sys/WeatherModel.py
index 6114507..6e7736e 100644
--- a/aman/sys/WeatherModel.py
+++ b/aman/sys/WeatherModel.py
@@ -132,11 +132,10 @@ class WeatherModel:
             else:
                 self.LastWeatherUpdate = None
 
-    def calculateGS(self, altitude : int, ias : int, heading : int):
+    def interpolateWindData(self, altitude : int):
         self.updateWindModel()
-        tas = self.calculateTAS(altitude, ias)
 
-        # initialize the wind data
+        # initialized the wind data
         if None != self.WindDirectionModel and None != self.WindSpeedModel:
             direction = 0.0
             speed = 0.0
@@ -151,5 +150,32 @@ class WeatherModel:
             speed = 0
             direction = 0
 
-        # calculate the ground speed based on the headwind component
+        return speed, direction
+
+    def calculateGS(self, altitude : int, ias : int, heading : int):
+        speed, direction = self.interpolateWindData(altitude)
+        tas = self.calculateTAS(altitude, ias)
         return tas + speed * math.cos(math.radians(direction) - math.radians(heading))
+
+    def convertGSToTAS(self, altitude : int, gs : int, heading : int):
+        speed, direction = self.interpolateWindData(altitude)
+        return gs - speed * math.cos(math.radians(direction) - math.radians(heading))
+
+    def estimateCourse(self, altitude : int, gs : int, heading : int):
+        tas = self.convertGSToTAS(altitude, gs, heading)
+        speed, direction = self.interpolateWindData(altitude)
+
+        aca = heading - direction
+        wca = speed * aca / tas
+
+        if 0 <= aca:
+            course = heading + wca
+        else:
+            course = heading - wca
+
+        while 0 > course:
+            course += 360
+        while 360 < course:
+            course -= 360
+
+        return course