Spheres

A Java package for doing spherical trigonometry without all the messy (and cpu intensive) trigonometry. The spheres package includes classes for points, spherical polygons, latitude/longitude bounding boxes, orbits, and scenes. Spheres documentation includes a variety of algorithm descriptions for performing areal comparisons on the sphere.
The spheres package itself performs areal comparisons on the sphere for spherical polygons, lat/lon bounding boxes, orbits, and scenes. At the moment the package is incomplete and not fully tested, except for the parts we're actually using. The javadoc documentation is on-line to give you an idea of what it does, or should do. The source code and the class files are also available in separate jar files (right click and "save as"). Or, if you're really keen, there's everything in one big jar file.
The Spheres package is licensed under the GNU General Public License.

Basic class descriptions:
Point
LongitudeRange
Sphere
SphericalPolygon
LatLonBoundingBox
GreatCircle
GreatCircleArc
Orbit
Scene

Algorithm descriptions:
Great Circle intersects Great Circle
Great Circle Arc intersects Great Circle Arc
Great Circle intersects Latitude
Great Circle Arc intersects Latitude Segment

SphericalPolygon contains Point
SphericalPolygon overlaps SphericalPolygon
SphericalPolygon overlaps LatLonBoundingBox
SphericalPolygon overlaps Scene

As the Spheres package is still in development we'd appreciate any feedback you may have.

Author: Ross Swick

Please send comments, questions and queries regarding this project to swick@geospatialmethods.org

Last modified: Fri Jun 20 15:50:55 2003