Dwell time

<h4>Dwell Time and Hits per Scan</h4>

Most processes in pulse radar are time-dependent. So there are some terms etablished to desribe
this time dependence.

<h4>Dwell Time</h4>

The time that an antenna beam spends on a target is called dwell time <span class="fsymbol">T<sub>D</sub></span>.
The dwell time of a 2D-search radar depends predominantly on

<ul><li>the antennas horizontally beam width <span class="fsymbol">Θ<sub>AZ</sub></span> and </li>
<li>the turn speed <span class="fsymbol">n</span> of the antenna (rotations per minute).</li>
</ul>

The dwell time can be calculated using the following equation:

The value of hits per scan <span class="fsymbol">m</span> says how many echo signals <span style="font-style: italic;">per single target</span>
during every antenna swing are received. The hit number stands e.g. for a search radar with a rotating
antenna for the number of the received echo pulses of a single target per antenna turn.
The dwell time <span class="fsymbol">T<sub>D</sub></span> and the
pulse repetition time <span class="fsymbol">PRT</span></a>
determine the value of hits per scan.

So that radar equipment can evaluate the target informations with sufficient precision,
hit numbers are between 1 and 20 as necessary, which depends on the radar set operating mode.

Main Menu

See Also

Main Menu