diff --git a/MapControl/Shared/AzimuthalEquidistantProjection.cs b/MapControl/Shared/AzimuthalEquidistantProjection.cs
index 8e522514..1e6db43f 100644
--- a/MapControl/Shared/AzimuthalEquidistantProjection.cs
+++ b/MapControl/Shared/AzimuthalEquidistantProjection.cs
@@ -28,12 +28,12 @@ namespace MapControl
 
         public override Matrix RelativeScale(double latitude, double longitude)
         {
-            (var cosC, var _, var _) = GetPointValues(latitude, longitude);
+            var p = GetProjectedPoint(latitude, longitude);
             var k = 1d;
 
-            if (cosC < 1d)
+            if (p.CosC < 1d)
             {
-                var c = Math.Acos(cosC);
+                var c = Math.Acos(p.CosC);
                 k = c / Math.Sin(c); // p.195 (25-2)
             }
 
@@ -42,16 +42,16 @@ namespace MapControl
 
         public override Point? LocationToMap(double latitude, double longitude)
         {
-            (var cosC, var x, var y) = GetPointValues(latitude, longitude);
+            var p = GetProjectedPoint(latitude, longitude);
             var k = 1d;
 
-            if (cosC < 1d)
+            if (p.CosC < 1d)
             {
-                var c = Math.Acos(cosC);
+                var c = Math.Acos(p.CosC);
                 k = c / Math.Sin(c); // p.195 (25-2)
             }
 
-            return new Point(EarthRadius * k * x, EarthRadius * k * y); // p.195 (22-4/5)
+            return new Point(EarthRadius * k * p.X, EarthRadius * k * p.Y); // p.195 (22-4/5)
         }
 
         public override Location MapToLocation(double x, double y)
diff --git a/MapControl/Shared/AzimuthalProjection.cs b/MapControl/Shared/AzimuthalProjection.cs
index 825f88fd..c24bd069 100644
--- a/MapControl/Shared/AzimuthalProjection.cs
+++ b/MapControl/Shared/AzimuthalProjection.cs
@@ -3,7 +3,7 @@
 namespace MapControl
 {
     /// <summary>
-    /// See "Map Projections - A Working Manual" (https://pubs.usgs.gov/publication/pp1395).
+    /// See "Map Projections - A Working Manual" (https://pubs.usgs.gov/publication/pp1395), p.141.
     /// </summary>
     public abstract class AzimuthalProjection : MapProjection
     {
@@ -14,22 +14,33 @@ namespace MapControl
 
         public double EarthRadius { get; set; } = Wgs84MeanRadius;
 
-        protected (double, double, double) GetPointValues(double latitude, double longitude)
+        public readonly struct ProjectedPoint
         {
-            var phi = latitude * Math.PI / 180d;
-            var phi1 = Center.Latitude * Math.PI / 180d;
-            var dLambda = (longitude - Center.Longitude) * Math.PI / 180d; // λ - λ0
-            var cosPhi = Math.Cos(phi);
-            var sinPhi = Math.Sin(phi);
-            var cosPhi1 = Math.Cos(phi1);
-            var sinPhi1 = Math.Sin(phi1);
-            var cosLambda = Math.Cos(dLambda);
-            var sinLambda = Math.Sin(dLambda);
-            var cosC = sinPhi1 * sinPhi + cosPhi1 * cosPhi * cosLambda; // (5-3)
-            var x = cosPhi * sinLambda;
-            var y = cosPhi1 * sinPhi - sinPhi1 * cosPhi * cosLambda;
+            public double X { get; }
+            public double Y { get; }
+            public double CosC { get; }
 
-            return (cosC, x, y);
+            public ProjectedPoint(double centerLatitude, double centerLongitude, double latitude, double longitude)
+            {
+                var phi = latitude * Math.PI / 180d;
+                var phi1 = centerLatitude * Math.PI / 180d;
+                var dLambda = (longitude - centerLongitude) * Math.PI / 180d; // λ - λ0
+                var cosPhi = Math.Cos(phi);
+                var sinPhi = Math.Sin(phi);
+                var cosPhi1 = Math.Cos(phi1);
+                var sinPhi1 = Math.Sin(phi1);
+                var cosLambda = Math.Cos(dLambda);
+                var sinLambda = Math.Sin(dLambda);
+
+                X = cosPhi * sinLambda;
+                Y = cosPhi1 * sinPhi - sinPhi1 * cosPhi * cosLambda;
+                CosC = sinPhi1 * sinPhi + cosPhi1 * cosPhi * cosLambda; // (5-3)
+            }
+        }
+
+        protected ProjectedPoint GetProjectedPoint(double latitude, double longitude)
+        {
+            return new ProjectedPoint(Center.Latitude, Center.Longitude, latitude, longitude);
         }
 
         protected Location GetLocation(double x, double y, double rho, double sinC)
diff --git a/MapControl/Shared/GnomonicProjection.cs b/MapControl/Shared/GnomonicProjection.cs
index b4c83a6d..0f264b3e 100644
--- a/MapControl/Shared/GnomonicProjection.cs
+++ b/MapControl/Shared/GnomonicProjection.cs
@@ -28,27 +28,27 @@ namespace MapControl
 
         public override Matrix RelativeScale(double latitude, double longitude)
         {
-            (var cosC, var x, var y) = GetPointValues(latitude, longitude);
-            var k = 1d / cosC; // p.165 (22-3)
+            var p = GetProjectedPoint(latitude, longitude);
+            var k = 1d / p.CosC; // p.165 (22-3)
             var h = k * k; // p.165 (22-2)
 
             var scale = new Matrix(h, 0d, 0d, k, 0d, 0d);
-            scale.Rotate(-Math.Atan2(y, x) * 180d / Math.PI);
+            scale.Rotate(-Math.Atan2(p.Y, p.X) * 180d / Math.PI);
             return scale;
         }
 
         public override Point? LocationToMap(double latitude, double longitude)
         {
-            (var cosC, var x, var y) = GetPointValues(latitude, longitude);
+            var p = GetProjectedPoint(latitude, longitude);
 
-            if (cosC <= 0d)
+            if (p.CosC <= 0d)
             {
                 return null;
             }
 
-            var k = 1d / cosC; // p.165 (22-3)
+            var k = 1d / p.CosC; // p.165 (22-3)
 
-            return new Point(EarthRadius * k * x, EarthRadius * k * y); // p.165 (22-4/5)
+            return new Point(EarthRadius * k * p.X, EarthRadius * k * p.Y); // p.165 (22-4/5)
         }
 
         public override Location MapToLocation(double x, double y)
diff --git a/MapControl/Shared/MapProjection.cs b/MapControl/Shared/MapProjection.cs
index 8657486f..3e9f53eb 100644
--- a/MapControl/Shared/MapProjection.cs
+++ b/MapControl/Shared/MapProjection.cs
@@ -28,8 +28,8 @@ namespace MapControl
     public abstract class MapProjection
     {
         public const double Wgs84EquatorialRadius = 6378137d;
-        public const double Wgs84MeterPerDegree = Wgs84EquatorialRadius * Math.PI / 180d;
         public const double Wgs84Flattening = 1d / 298.257223563;
+        public const double Wgs84MeterPerDegree = Wgs84EquatorialRadius * Math.PI / 180d;
 
         // Arithmetic mean radius (2*a + b) / 3 == (1 - f/3) * a.
         // See https://en.wikipedia.org/wiki/Earth_radius#Arithmetic_mean_radius.
diff --git a/MapControl/Shared/OrthographicProjection.cs b/MapControl/Shared/OrthographicProjection.cs
index c94d425d..3c7e401c 100644
--- a/MapControl/Shared/OrthographicProjection.cs
+++ b/MapControl/Shared/OrthographicProjection.cs
@@ -28,19 +28,19 @@ namespace MapControl
 
         public override Matrix RelativeScale(double latitude, double longitude)
         {
-            (var cosC, var x, var y) = GetPointValues(latitude, longitude);
-            var h = cosC; // p.149 (20-5)
+            var p = GetProjectedPoint(latitude, longitude);
+            var h = p.CosC; // p.149 (20-5)
 
             var scale = new Matrix(h, 0d, 0d, 1d, 0d, 0d);
-            scale.Rotate(-Math.Atan2(y, x) * 180d / Math.PI);
+            scale.Rotate(-Math.Atan2(p.Y, p.X) * 180d / Math.PI);
             return scale;
         }
 
         public override Point? LocationToMap(double latitude, double longitude)
         {
-            (var cosC, var x, var y) = GetPointValues(latitude, longitude);
+            var p = GetProjectedPoint(latitude, longitude);
 
-            return cosC >= 0d ? new Point(EarthRadius * x, EarthRadius * y) : null; // p.149 (20-3/4)
+            return p.CosC >= 0d ? new Point(EarthRadius * p.X, EarthRadius * p.Y) : null; // p.149 (20-3/4)
         }
 
         public override Location MapToLocation(double x, double y)
diff --git a/MapControl/Shared/StereographicProjection.cs b/MapControl/Shared/StereographicProjection.cs
index a1304be7..b166c489 100644
--- a/MapControl/Shared/StereographicProjection.cs
+++ b/MapControl/Shared/StereographicProjection.cs
@@ -28,18 +28,18 @@ namespace MapControl
 
         public override Matrix RelativeScale(double latitude, double longitude)
         {
-            (var cosC, var _, var _) = GetPointValues(latitude, longitude);
-            var k = 2d / (1d + cosC); // p.157 (21-4), k0 == 1
+            var p = GetProjectedPoint(latitude, longitude);
+            var k = 2d / (1d + p.CosC); // p.157 (21-4), k0 == 1
 
             return new Matrix(k, 0d, 0d, k, 0d, 0d);
         }
 
         public override Point? LocationToMap(double latitude, double longitude)
         {
-            (var cosC, var x, var y) = GetPointValues(latitude, longitude);
-            var k = 2d / (1d + cosC); // p.157 (21-4), k0 == 1
+            var p = GetProjectedPoint(latitude, longitude);
+            var k = 2d / (1d + p.CosC); // p.157 (21-4), k0 == 1
 
-            return new Point(EarthRadius * k * x, EarthRadius * k * y); // p.157 (21-2/3)
+            return new Point(EarthRadius * k * p.X, EarthRadius * k * p.Y); // p.157 (21-2/3)
         }
 
         public override Location MapToLocation(double x, double y)
diff --git a/MapProjections/Shared/Wgs84OrthographicProjection.cs b/MapProjections/Shared/Wgs84OrthographicProjection.cs
index 57458f59..1a22b650 100644
--- a/MapProjections/Shared/Wgs84OrthographicProjection.cs
+++ b/MapProjections/Shared/Wgs84OrthographicProjection.cs
@@ -1,7 +1,15 @@
-using System.Globalization;
+using System;
+using System.Globalization;
+#if WPF
+using System.Windows.Media;
+#endif
 
 namespace MapControl.Projections
 {
+    /// <summary>
+    /// Spherical Orthographic Projection - AUTO2:42003.
+    /// See "Map Projections - A Working Manual" (https://pubs.usgs.gov/publication/pp1395), p.148-150.
+    /// </summary>
     public class Wgs84OrthographicProjection : ProjNetMapProjection
     {
         public Wgs84OrthographicProjection()
@@ -25,5 +33,15 @@ namespace MapControl.Projections
             CoordinateSystemWkt = string.Format(
                 CultureInfo.InvariantCulture, wktFormat, Center.Latitude, Center.Longitude);
         }
+
+        public override Matrix RelativeScale(double latitude, double longitude)
+        {
+            var p = new AzimuthalProjection.ProjectedPoint(Center.Latitude, Center.Longitude, latitude, longitude);
+            var h = p.CosC; // p.149 (20-5)
+
+            var scale = new Matrix(h, 0d, 0d, 1d, 0d, 0d);
+            scale.Rotate(-Math.Atan2(p.Y, p.X) * 180d / Math.PI);
+            return scale;
+        }
     }
 }
diff --git a/MapProjections/Shared/Wgs84StereographicProjection.cs b/MapProjections/Shared/Wgs84StereographicProjection.cs
index 0ed274df..54408fcf 100644
--- a/MapProjections/Shared/Wgs84StereographicProjection.cs
+++ b/MapProjections/Shared/Wgs84StereographicProjection.cs
@@ -1,7 +1,14 @@
 using System.Globalization;
+#if WPF
+using System.Windows.Media;
+#endif
 
 namespace MapControl.Projections
 {
+    /// <summary>
+    /// Spherical Stereographic Projection - AUTO2:97002.
+    /// See "Map Projections - A Working Manual" (https://pubs.usgs.gov/publication/pp1395), p.157-160.
+    /// </summary>
     public class Wgs84StereographicProjection : ProjNetMapProjection
     {
         public Wgs84StereographicProjection()
@@ -25,5 +32,13 @@ namespace MapControl.Projections
             CoordinateSystemWkt = string.Format(
                 CultureInfo.InvariantCulture, wktFormat, Center.Latitude, Center.Longitude);
         }
+
+        public override Matrix RelativeScale(double latitude, double longitude)
+        {
+            var p = new AzimuthalProjection.ProjectedPoint(Center.Latitude, Center.Longitude, latitude, longitude);
+            var k = 2d / (1d + p.CosC); // p.157 (21-4), k0 == 1
+
+            return new Matrix(k, 0d, 0d, k, 0d, 0d);
+        }
     }
 }