What is Aspect?
Aspect of a target vessel is the relative bearing of the Own vessel from the Target
vessel.
OR
The angle between target vessel’s course and the theoretical line of sight.
It is expressed as RED or GREEN
In a WOA Triangle that we make for radar plotting
WO is Way Own Own Ship’s Course
WA is Way Another Target Ship’s Course
OA is Line of approach Between own ship snd tsrget ship
Angle “O” is relative bearing of target vessel
Angle “W” is angle between Target vessel’s Course and Own Ship’s Course.
Angle “A” is Aspect angle of target ship. RED or GREEN
Red or Green will depend upon which side you can see of that vessel. To that you
have to imagine complete the WOA triangle and mark “C” on the sheet.
How to Find Aspect is RED or GREEN
Extend WA line and put a arrow on that.
Extend OA line and “C” will be on side of
Vector OA as shown in Picture.
If ROC is there then Extended OA in direction of A will pass through “C” which
is center of the Plot.
Now Imagine Target ship on point “A” heading same as vector WA and your ship
on point “C” in heading same as vector WO.
It is clear that u can see the Stbd side of another ship and Stbd side is green
therefore aspect will be Green 90 approx in above pic.
Some more to clarification on Aspect Colour.
Red(pink) Line is line of Sight and Course of target vessel is indicated with Arrow.
Aspect for above targets
Target A: Green 17° approx
Target B: Red 10° approx
Target C: Zero Aspect (End on) word head on is wrong
Target D: Red 12° approx