Using a Java Web-based Graphical User Interface to access the SOHO Data Arch ive

This paper presents the architecture of a Java web-based graphical interface dedicated to the access of the SOHO Data archive. This application allows local and remote users to search in the SOHO data catalog and retrieve the SOHO data files from the archive. It has been developed at MEDOC (Multi-Experiment Data and Operations Centre), located at the Institut d'Astrophysique Spatiale (Orsay, France), which is one of the European Archives for the SOHO data. This development is part of a joint effort between ESA, NASA and IAS in order to implement long term archive systems for the SOHO data. The software architecture is built as a client-server application using Java language and SQL above a set of components such as an HTTP server, a JDBC gateway, a RDBMS server, a data server and a Web browser. Since HTML pages and CGI scripts are not powerful enough to allow user interaction during a multi-instrument catalog search, this type of requirement enforces the choice of Java as the main language. We also discuss performance issues, security problems and portability on different Web browsers and operating syste ms.