The Distributed Radar Data Acquisition and Control System (DIRAC)—A new Generation of Multi-Controller Networks Running an Open Radar Control Software

Subject: In 1998, in the course of the COST 75 seminar in Locarno, Gematronik has introduced the new concept for an open design of a heterogeneous Radar data acquisition, control and monitoring system. Now, after being implemented in Gematronik's new METEOR 500/1500 Radar series, the first results can be reported.

Background: Modern radar meteorology raised demanding requests for an enhanced control and data flow as integral part of a radar sensor. The objectives are: a flexible integration of additional sensors in order to measure additional radar- and associated operational parameters (extended evaluation and research, simplified maintenance), scalable and customized systems based on a flexible, modular design, that support component upgrades and interfacing with third-party hard- and software as well as network integration of radars and product distribution via Internet/ Intranet. The latest developments in data/signal processing and network/web technologies create opportunities for a migration to highly flexible, open configurations. Those systems rely on hardware-independent, embedded operating systems, programming languages and software tools running on COTS (Commercial off-the-shelf) hardware components.

Concept: Distributed controlling devices How to bring the right level of computing power into the individual modules? Realtime requirements and benefits like scalable performance, decentralized, simultaneous processing tasks and heterogeneous COTS devices. Radar sensor network architecture The 3-tier network structure: Realtime device layer (Profibus/VMEbus), Pseudo-RT controlling layer (Radar LAN on Ethernet), Presentation layer (Open access LAN/WAN on Internet/Intranet), Newsserver/Postmaster concept. How to communicate? - The macro language RCL R(adar) C(ontrol) L(anguage) - An open specification of status/command syntax allows to communicate from 'everywhere to everyone'. The applications have transparent access to every module in the radar network. Complex acquisition and control procedures are easily configured via macro scripts. User Interfaces - Realtime visualization of control and data flow with Ravis Hardware-independent, non-proprietary techniques on the presentation layer: experiences with Java for realtime visualization and control of individual radars or radar networks (Ravis), Remote sensing and monitoring, Network and web capabilities, access security.

Results and benefits: · Extremely flexible design: auto-detection of system configurations, scalability, remote online interaction or even live software upgrades; · Samples for remote access capabilities - remote visualization, configuration and maintenance; · Interfacing of third party control and analysis software: 'RCL communication shell'; Examples with LabView.