Fix QFE calculation: fix lapse rate and rounding (#78)

vatis-project · Jan 16, 2025 · 10b1d8f · 10b1d8f
1 parent c928e3c
commit 10b1d8f
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/vATIS.Desktop/Atis/Nodes/AltimeterSettingNode.cs b/vATIS.Desktop/Atis/Nodes/AltimeterSettingNode.cs
@@ -103,12 +103,12 @@ public override string ParseVoiceVariables(Value node, string? format)
 
     private static int CalculateQfe(double qnh, double elevationFeet)
     {
-        // Pressure lapse rate: approximately 1 hPa per 30 feet
-        const double pressureLapseRateFeet = 30.0;
+        // Pressure lapse rate: approximately 1 hPa per 27.3 feet
+        const double pressureLapseRateFeet = 27.3;
 
         // Calculate the QFE
         var qfe = qnh - (elevationFeet / pressureLapseRateFeet);
-        return (int)qfe;
+        return (int)Math.Ceiling(qfe);
     }
 
     private async Task Parse(Pressure? pressure)