City Sailingvideo
Radar Course Setting Up plotting you position, Electronic Bearing Line, Variable Range Marker.
17 March 2025 · 10 min · 605 views · Torbay
What this video covers
Radar functions by transmitting pulses of radio energy that reflect off targets and return to the receiver, with pulse length and beam width determining the clarity and separation of objects on the display.0:06 A shorter pulse length provides better definition, while a standard five-degree beam width can cause two closely spaced targets to appear as one if the beam straddles them.1:33 To obtain an accurate position fix in Torbay, the operator uses the Variable Range Marker (VRM) to measure distances to prominent headlands like Roundham Head and East Shag.4:26 Because radar beams can expand a target's appearance by half the beam width, the operator adjusts bearings by approximately 2.5 degrees.9:23 By plotting two range arcs from the VRM and one Electronic Bearing Line (EBL) on a chart, the navigator establishes a position fix, which is then cross-referenced with depth soundings and visual observations.6:05 Using independent radar data provides a reliable secondary navigation method.9:44
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