VME-based radar system tracks ships in real time
To assist in reducing the number of offshore shipping incidents in the English Channel, six VME-based radar systems have been installed at the Maritime Rescue Coordination Center (MRCC; Dover, England). Developed under contract to EDS (Stockley Park, Uxbridge, England) by Primagraphics (Litlington, England), the radar systems provide early warning of ships entering hazardous areas, dragging their anchors, or disappearing from view.
Based around Primagraphics` Varsity series of OEM digitizer, storage, processing, and display controller boards, the radar systems allow operators to overlay real-time video data, vessel position information, and surveillance maps (see Fig. 1). In operation, radar video signals are received from one of three antennas positioned on the English coast and are then fed to the radar consoles via a switching matrix. This matrix switch allows each operator to select any radar image for viewing. At each console, the radar video and timing signals are delivered to the Virgo+ radar interface card.
After digitization, data are transferred over Primagraphics` synchronous secondary 60-Mbyte/s P2-based Primabus to another VME-board, called Viceroy, that acts as a range angle store (see Fig. 2). As soon as a completed radar sector has been received, it is again transferred over the Primabus to a pair of Velocity+ RISC-based processors. Based on the AMD 29050 RISC processor, these two VME processor boards look independently and simultaneously for new targets in the data and perform target tracking.
Controlled by an external host, the tracker subsystem generates the position and speed of the ships and broadcasts the data over an Ethernet network to each radar console. To display the radar images, which are graphical representations of each ship and a vector map of the area, each radar console first scan-converts the radar data and then overlays the mapped data onto a 2k x 2k, 28-in. Sony monitor using a Vanguard VME display controller.
According to Primagraphics, the application program provides a multiwindow, interactive display that manages the tracker, the radar, and the graphics display using standard library software modules.
