Radar Image Server (RIS) Software

Radar Image Server (RIS) Software

SPx Radar Image Server (RIS) is a scan conversion server that receives radar video and scan converts into one or more radar images that may be delivered to a client application or a standard web browser. Interfacing to a hardware or network source of radar video, SPx-RIS accepts polar format video and scan converts into a bitmap image that may be distributed to any number of clients.

Unlike other SPx scan conversion solutions, the RIS does not permit the client application to change the view contained in the distributed bitmap. The view is preset in the RIS, although a single RIS server can distribute multiple views. In a typical application, a RIS server can be configured to distribute scan converted video for several different views, perhaps representing full radar coverage and then several zoom views or selected areas. The client software then receives these images and may display them in a custom-written application with optional graphics, or else in a standard browser window with the supplied Java applet.

Where it is required to display a radar image with fixed views, RIS offers an extremely cost-effective solution, since no client licenses are needed. The radar data can be displayed in a standard web browser using the supplied Java applet. Any number of client computers can connect to a single RIS server and display the radar image. Since bitmaps are distributed via UDP multicast, the network bandwidth is unaffected by the number of connected clients.

The distribution rate of the image from the RIS server may be configured so that bitmaps are distributed either once per scan, in quadrants or at more frequent intervals. The client display will not show a smoothly rotating radar sweep (unlike other SPx scan conversion solutions), but for many applications where a simple radar image is required this will not be a limitation. In the screen shot below, a single RIS is distributing 4 streams of video to a client computer which is using Internet Explorer to view the radar. The 4 streams show different views and are being updated once per scan of the radar.

SPx RIS is a Windows application. A user interface allows for full configuration of the server in terms of the number of streams, radar views, update rate, radar colour and optional metadata that can accompany the video picture. When configured, the RIS runs without operator assistance and the software may be configured to start automatically for unattended server operation.

RIS allows 1, 2 or 4 radar views to be distributed (license options) as streams. Each stream has a window size, radar offset and radar scale factor. In a typical application, one stream will be programmed for the full coverage of the radar and then one or more additional streams will provide zooms of selected areas. Each stream can be given a name and accompanied by metadata in the form of name + value strings. The streams of images and metadata are distributed using UDP to a programmed IP address and port. The frequency of distribution of the bitmap may be configured, allowing for once-per-scan, quadrant or time-based updates.

On the client side, an application may subscribe to one or more streams of data from RIS. It receives the bitmap data and accompanying metadata which it can display in a graphical application. RIS is provided with a Java applet that allows radar images to be displayed in a standard web browser. A multi-view radar display can easily be configured using a standard web browser.

Multiple RIS instances can be used for multi-radar installations. For two radars, for example, two instances of RIS can each provide multiple streams for each radar. Different clients could then select videos from any stream of either server.

RIS Application

The RIS application runs under Windows and provides a user-interface for configuration of the server. This can be used to define the details of the radar capture, the views to be scan converted and delivered, the update rate of the bitmaps and the delivery address (single client or multiple clients through a multicast distribution). Controls include:

  • Define the ID of the RIS server, allowing the client to receive from multiple RIS servers and distinguish between them.
  • Set the address for distribution of the radar images. This can be a unicast or multicast address.
  • Define the source of radar video for the server, which may be test pattern, network or HPx radar interface card.
  • Recording of individual frames of video to file.
  • Define up to 4 radar windows, with each window having a programmable size, view for the radar images.
  • Define the frequency of transmission of each image, including whether incremental with-the-sweep updates are desired or just once-per-scan.
  • Select the compression type to be used for the distribution of the images.
  • Define additional metadata to be sent with the radar to each client.

Client Support Software

No client licenses are needed for the RIS. Library software is supplied to allow a custom application to receive the radar images and display them in a Windows application. Alternatively, a standard web browser may be used to display the updating radar images.

Choosing RIS for Radar Display

Is the RIS the right choice for your radar display requirement? Consider the following:

  • The RIS runs in a server and scan converts the radar in that server. Any number of clients can receive the scan converted images from the RIS, but the clients cannot change the scan converted view. In contrast, when scan conversion is handled in the client (with SPx C++ library or SPx RDC) then the client receives the polar data and has full control over the presentation of the radar video.
  • The RIS requires only a single license for the RIS application itself. The client display of the radar does not require any licenses. This makes the RIS approach very cost-effective for showing radar video on many clients, provided those clients are satifisfied with a fixed view of the radar.