The Constellation server, and therefore both the security components which will be developed and the existing Sensor Observation Service server module, is a Java Language application built to run in a Java Enterprise Edition (JEE) environment.
This system is broadly used as a platform for web services and therefore can be run in an extremely wide variety of hardware platforms, on all major operating systems, and in many different configurations.
The wished environment is to run Constellation inside a Glassfish application server running on a unix-like operating system, such as an OpenSolaris or a distribution of GNU and other tools on a Linux kernel such as Ubuntu.
The core of Constellation
The Constellation project aims to provide a complete solution for the management, discovery, exploitation, and distribution of geographic data within a distributed services framework based on standards compliant, free software modules.
The project follows well defined standards based on, for geographic data, the specifications of the Open Geospatial Consortium (OGC) and the International Organisation for Standardisation (ISO) and, for software development, the specifications of the Java language as developed within the Java Community Process.
Constellation uses a fully modular architecture which enables a completely flexible re-assembly of components to target a wide range of applications in diverse fields.
The very concept of a Spatial Data Infrastructure depends inherently on the use of Web Services for geographic data which follow the accepted norms and specifications since that is required to guarantee interoperability. To enable the standards compliant development of Geospatial Web Services within an SDI, Constellation is based on several core components, all of them free software:
- Metro: the project regroups most of the core Java specifications related to WebService handling such as JAX-WS to handle SOAP based services and JAX-RS (Jersey) for RESTful services.
- GeoAPI: a collection of Java language interfaces for the OGC and ISO geospatial specifications, which is itself a formal OGC specification and is currently aiming to gain its own "Standard Working Group" within the OGC.
- Geotools: a library of components for the complete handling of geospatial data which provides, among other components, the reference implementation of the GeoAPI interfaces.
- JScience: the reference implementation of the Java specification for units of measure (JSR-275), providing the rigorous handling of units and their conversion. This modular architecture, the strict respect for accepted norms, and the distribution of all software components under the standard free software license for the Java language jointly guarantee to implementers who base their services on Constellation the fullest flexibility for service development and the long term persistence of their services within their spatial data infrastructure.
Constellation currently implements the following web services:
- SOS (1.0) (SOAP)
- WCS (1.0 et 1.1.1) (REST)
- CS-W (2.0.2) (SOAP)
- WMS (1.1.1 et 1.3.0) (REST) (Raster only with a vector prototype)
and implements the following OGC specifications:
- Symbology Encoding 1.0
- SLD 1.0 et 1.1
- Filter Encoding 1.0 et 1.1
- O&M 1.0 part. 1 et 2
- SWE-Commons 1.0.1
Constellation for Sensor Web Enablement
The Constellation project integrates the technical foundation for SWE services and already implements an SOS web service which implements all of version 1.0 of the specification including the transactional aspects.
That work has lead to a prototype of a web service based monitoring for remote, in situ, hydrological sensors.
Constellation and Security
Constellation is going to embed the security process provided by the XACML standard. Please, have a look to this page in order to have more information about security policy in Constellation : Security.