Coordinate Transformations

Idea

Develop a web service to perform simple coordinate transformations for astronomy. This web service could be used in combination with Conesearch or SIAP servers to provide greater functionality for those services. Example uses - conesearch in Galactic coordinates, conesearch in the instantaneous epoch (for observers at the telescope). We also create a simple web site for simple access to the service.

Team

Webservice

We developed the coordtrans web service using as a basis the Nums example found in nvoss/dev/simplewebservice in the Software (we ran through this example in the SOAP Webservices section of the Summer School Session on Utilizing VO Standards and Protocols: Server Side). The server code is written in java (CoordTrans.java) and compiled and deployed to axis using ant (Build.xml).

Available transformations

  • sex2Dec - Convert RA and DEC in sexigesimal hours and degrees (space separated) to decimal degrees
  • dec2Sex - The inverse of the above
  • precess - Precess equatorial co-ordinates from one epcoch to another. The algorithm implemented here is only exact for precession from 1950-2000, but should be accurate enough for dates around then.
  • gal2Equ - Convert Galactic lattitude and longitude to RA and DEC (all angles in decimal degrees, equatorial coordinates are J2000)
  • equ2Gal - The inverse of the above
  • sgal2Equ - Convert Supergalactic lattitude and longitude to RA and DEC (all angles in decimal degrees, equatorial coordinates are J2000)
  • equ2Sgal - The inverse of the above.

Website

The web form was written using jsp (CoordTrans.jsp), and provides a simple access to all of the available transformations.

File Size: Date: Comment:
CoordTrans.java 8000 23 Sep 2004 - 15:36 Java source for CoordTrans Server
CoordTransBuild.xml 1519 23 Sep 2004 - 15:39 Build file for CoordTrans server
CoordTrans.jsp.txt 9354 23 Sep 2004 - 15:55 Source code for jsp file for CoordTrans web form
CoordTrans.wsdl 10775 30 Sep 2004 - 19:38 WSDL file for CoordTrans server