Question

6. Explain Radar Bearing and Range Resolution

Answer 1

Given that

  Radar Bearing and Range Resolution:

Radar Bearing:

  Bearing, or azimuth, resolution is the ability of a radar system to separate objects at the same rangebut at different bearings. The degree of bearing resolution depends on radar beam width and the range ofthe targets. Range is a factor in bearing resolution because the radar beam spreads out as range increases.A radar beam is defined in width in terms of half power points.

  The True Bearing referenced to true north of radar target is the angle between true north and a line pointed directly at the target.The bearing angle to the radar target may also be measured in a clockwise direction from the centerline of your own ship or aircraft and is referred to as the relative bearing.

  The angular determination of the target is determined by the directivity of the antenna. Directivity, sometimes known as the directive gain, is the ability of the antenna to concentrate the transmitted energy in a particular direction. An antenna with high directivity is also-called a directive antenna.

  Range Resolution:

  Range resolution is the ability of radar system to distinguish between two or more targets on the same bearing but at different ranges. The degree of range resolution depends on the width of the transmitted pulse, the types and sizes of targets, and the efficiency of the receiver and indicator.

Radar range resolution is the capability of the radar to distinguish or resolve nearby adjacent targets in the range. Search radars usually will have poor resolution and will distinguish two targets at about 100 meters apart.

The radar range resolution mainly depends upon following parameters/factors:
1) transmitted pulse width
2) beamwidth
3) type of target
4) size of target
5) radar receiver efficiency

Range resolution as a distance can be calculated as follows

R_res = c * τ /2