Index: trunk/src/org/openstreetmap/josm/data/projection/Projections.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/projection/Projections.java	(revision 9548)
+++ trunk/src/org/openstreetmap/josm/data/projection/Projections.java	(revision 9549)
@@ -30,4 +30,5 @@
 import org.openstreetmap.josm.data.projection.datum.WGS84Datum;
 import org.openstreetmap.josm.data.projection.proj.AlbersEqualArea;
+import org.openstreetmap.josm.data.projection.proj.CassiniSoldner;
 import org.openstreetmap.josm.data.projection.proj.ClassProjFactory;
 import org.openstreetmap.josm.data.projection.proj.DoubleStereographic;
@@ -86,4 +87,5 @@
     static {
         registerBaseProjection("aea", AlbersEqualArea.class, "core");
+        registerBaseProjection("cass", CassiniSoldner.class, "core");
         registerBaseProjection("josm:smerc", Mercator.class, "core");
         registerBaseProjection("lcc", LambertConformalConic.class, "core");
Index: trunk/src/org/openstreetmap/josm/data/projection/proj/AlbersEqualArea.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/projection/proj/AlbersEqualArea.java	(revision 9548)
+++ trunk/src/org/openstreetmap/josm/data/projection/proj/AlbersEqualArea.java	(revision 9549)
@@ -20,9 +20,9 @@
  * package of the USGS survey. USGS work is acknowledged here.
  * <p>
-  * This class has been derived from the implementation of the Geotools project;
+ * This class has been derived from the implementation of the Geotools project;
  * git 8cbf52d, org.geotools.referencing.operation.projection.AlbersEqualArea
  * at the time of migration.
  * <p>
-* <b>References:</b>
+ * <b>References:</b>
  * <ul>
  *   <li> Proj-4.4.7 available at <A HREF="http://www.remotesensing.org/proj">www.remotesensing.org/proj</A><br>
Index: trunk/src/org/openstreetmap/josm/data/projection/proj/CassiniSoldner.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/projection/proj/CassiniSoldner.java	(revision 9549)
+++ trunk/src/org/openstreetmap/josm/data/projection/proj/CassiniSoldner.java	(revision 9549)
@@ -0,0 +1,99 @@
+// License: GPL. For details, see LICENSE file.
+package org.openstreetmap.josm.data.projection.proj;
+
+import static org.openstreetmap.josm.tools.I18n.tr;
+
+import org.openstreetmap.josm.data.Bounds;
+import org.openstreetmap.josm.data.projection.ProjectionConfigurationException;
+
+/**
+ * Cassini-Soldner Projection (EPSG code 9806).
+ * The Cassini-Soldner Projection is the ellipsoidal version of the Cassini
+ * projection for the sphere. It is not conformal but as it is relatively simple
+ * to construct it was extensively used in the last century and is still useful
+ * for mapping areas with limited longitudinal extent. It has now largely
+ * been replaced by the conformal Transverse Mercator which it resembles. Like this,
+ * it has a straight central meridian along which the scale is true, all other
+ * meridians and parallels are curved, and the scale distortion increases
+ * rapidly with increasing distance from the central meridian.
+ * <p>
+ * 
+ * This class has been derived from the implementation of the Geotools project;
+ * git 8cbf52d, org.geotools.referencing.operation.projection.CassiniSoldner
+ * at the time of migration.
+ */
+public class CassiniSoldner extends AbstractProj {
+
+    /**
+     * Meridian distance at the {@code latitudeOfOrigin}.
+     * Used for calculations for the ellipsoid.
+     */
+    private double ml0;
+
+    /**
+     * Contants used for the forward and inverse transform for the eliptical
+     * case of the Cassini-Soldner.
+     */
+    private static final double  C1= 0.16666666666666666666,
+                                 C2= 0.008333333333333333333,
+                                 C3= 0.041666666666666666666,
+                                 C4= 0.33333333333333333333,
+                                 C5= 0.066666666666666666666;
+
+    @Override
+    public String getName() {
+        return tr("Cassini-Soldner");
+    }
+
+    @Override
+    public String getProj4Id() {
+        return "cass";
+    }
+
+    @Override
+    public void initialize(ProjParameters params) throws ProjectionConfigurationException {
+        super.initialize(params);
+        if (params.lat0 == null)
+            throw new ProjectionConfigurationException(tr("Parameter ''{0}'' required.", "lat_0"));
+        double latitudeOfOrigin = Math.toRadians(params.lat0);
+        ml0 = mlfn(latitudeOfOrigin, Math.sin(latitudeOfOrigin), Math.cos(latitudeOfOrigin));
+    }
+
+    @Override
+    public double[] project(double phi, double lam) {
+        double sinphi = Math.sin(phi);
+        double cosphi = Math.cos(phi);
+
+        double n = 1.0 / (Math.sqrt(1.0 - e2 * sinphi * sinphi));
+        double tn = Math.tan(phi);
+        double t = tn * tn;
+        double a1 = lam * cosphi;
+        double c = cosphi * cosphi * e2 / (1 - e2);
+        double a2 = a1 * a1;
+
+        double x = n * a1 * (1.0 - a2 * t * (C1 - (8.0 - t + 8.0 * c) * a2 * C2));
+        double y = mlfn(phi, sinphi, cosphi) - ml0 + n * tn * a2 * (0.5 + (5.0 - t + 6.0 * c) * a2 * C3);
+        return new double[] {x, y};
+    }
+
+    @Override
+    public double[] invproject(double x, double y) {
+        double ph1 = inv_mlfn(ml0 + y);
+        double tn = Math.tan(ph1);
+        double t = tn * tn;
+        double n = Math.sin(ph1);
+        double r = 1.0 / (1.0 - e2 * n * n);
+        n = Math.sqrt(r);
+        r *= (1.0 - e2) * n;
+        double dd = x / n;
+        double d2 = dd * dd;
+        double phi = ph1 - (n * tn / r) * d2 * (0.5 - (1.0 + 3.0 * t) * d2 * C3);
+        double lam = dd * (1.0 + t * d2 * (-C4 + (1.0 + 3.0 * t) * d2 * C5)) / Math.cos(ph1);
+        return new double[] {phi, lam};
+    }
+
+    @Override
+    public Bounds getAlgorithmBounds() {
+        return new Bounds(-89, -1.0, 89, 1.0, false);
+    }
+}