Jump to content

3D radar

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by InternetArchiveBot (talk | contribs) at 22:45, 29 September 2016 (Rescuing 2 sources and tagging 0 as dead. #IABot (v1.2.4)). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Type 984 radar on HMS Victorious, 1961

3D radar provides for radar coverage in three dimensions, unlike the more common 2D radar. While the normal 2D radar provides range and azimuth, the 3D radar provides elevation information with range and azimuth. Applications include weather monitoring, air defense and surveillance.

The information provided by 3D radar has long been required, particularly for air defence and interception. Interceptors must be told the altitude to climb to before making an intercept. Before the advent of single unit 3D radars, this was achieved with separate search radars (giving range and azimuth) and separate height finding radars that could examine a target to determine altitude. These had little search capability, so were directed to a particular azimuth first found by the primary search radar.

Techniques

Diagram of a typical 2D radar rotating cosecant squared antenna pattern
Diagram of a typical 3D radar, a judicious mix of vertical electronic beam steering and mechanically horizontal movement of a pencil-beam

Steered beam radars steer a narrow beam through a scan pattern to build a 3-D picture. Examples include NEXRAD doppler weather radar (which uses a parabolic dish) and the AN/SPY-1 Passive electronically scanned array radar employed by the Ticonderoga class of guided missile cruisers and other ships so equipped with the Aegis Combat System.

Stacked beam radars emit and/or receive multiple beams of radio waves at two or more elevation angles. By comparing the relative strengths of the returns from each beam, the elevation of the target can be deduced. An example of a stacked beam radar is the Air Route Surveillance Radar.

See also

  • "CEA FAR 3D Radar". Archived from the original on 2004-08-13. Retrieved 2004-10-31. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  • "ESR 360L 3D Surveillance Radar". Archived from the original on 2006-09-23. Retrieved 2006-05-16. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)