RADAR room exercise 5

Position fixing with a RADAR

Measuring ranges and bearings

All RADAR sets have the ability to measure angles and distances. You can then draw these onto a chart to plot your position.
 

Plotting a position with three bearings	Plotting a position with three ranges

Middle Island is shown below as being

• 45 degrees Relative from the vessels heading, to which the RADAR is aligned. 
• 1.852 nautical miles from the RADAR room.
• Note: 
  • These angles are always measured in a clockwise direction. 
  • R stands for Relative and T stands for True.
  • I was forced to use an asterisk * for degrees on the drawings - don't do this.
  • The abbreviation used for nautical miles and minutes is '.

Point Effingham is shown below as being

• 347 degrees Relative and
• 1.4 nautical miles.

Converting relative bearings to true bearings

All Relative bearings must be converted into True before they can be plotted onto a navigational chart.



To convert Relative bearings to True, do this:

Ranges

The distance of 1.4 nautical miles can be measured off the latitude scale as 1.4 minutes of latitude, and scribed from Point Effingham with a compass or divider:

Exercise

Click here to go to an exercise about using the RADAR to find the range and bearing of some objects you can see from the RADAR room.

Click here to return to the main RADAR menu.