SUBSIM Radio Room Forums - View Single Post - Noobie: Best way to find bearing and range of a ship without map contact updates?

Frederf · 08-20-09, 12:51 AM

1. There's basically two ways, plot two points like you have been doing or plot one point and be really good as finding out AOB.

Don't feel limited to just two points though. Plot on 3 minute intervals and draw a line of "best fit" through a dozen points. You may find out the target is maneuvering or your measurements are of poor quality. Stadimeter ranges get a lot more accurate under 5000yd and make sure to have the right ID. Right after I take a stadimeter bearing I lower the scope just below the surface and mouse over the TDC results window for true bearing as I'm also reading the range. "3-2-6 at 34-hundred." Go to the navigation map and use the advanced ruler function to pull a line from your boat's dot to that range and true direction. Get it to 50yd and 1° accuracy. I write down the mark number along with the time on paper so I can do speed calculations later.

Try examining the AOB too. Try setting the AOB dial so the target's course matches up with your plotting estimates. Does it look right through the scope at the actual target? Double check and prepare to admit the first info was wrong.

2. The range is best gotten from the following sources in order of more accurate to least accurate: radar, stadimeter, and sonar. Radar, even without the realistic digital readout is better especially at ranges beyond 4000yd. The A-scope is hard to read due to its logarithmic scale but the PPI scope can give very good accuracy especially with a school ruler and a pocket calculator (scope radius is 205mm, target distance is 130mm. 20,000yd * (130/205) = ???).

08-20-09, 12:51 AM	#2
Frederf Seasoned Skipper Join Date: Apr 2005 Posts: 665 Downloads: 79 Uploads: 1	1. There's basically two ways, plot two points like you have been doing or plot one point and be really good as finding out AOB. Don't feel limited to just two points though. Plot on 3 minute intervals and draw a line of "best fit" through a dozen points. You may find out the target is maneuvering or your measurements are of poor quality. Stadimeter ranges get a lot more accurate under 5000yd and make sure to have the right ID. Right after I take a stadimeter bearing I lower the scope just below the surface and mouse over the TDC results window for true bearing as I'm also reading the range. "3-2-6 at 34-hundred." Go to the navigation map and use the advanced ruler function to pull a line from your boat's dot to that range and true direction. Get it to 50yd and 1° accuracy. I write down the mark number along with the time on paper so I can do speed calculations later. Try examining the AOB too. Try setting the AOB dial so the target's course matches up with your plotting estimates. Does it look right through the scope at the actual target? Double check and prepare to admit the first info was wrong. 2. The range is best gotten from the following sources in order of more accurate to least accurate: radar, stadimeter, and sonar. Radar, even without the realistic digital readout is better especially at ranges beyond 4000yd. The A-scope is hard to read due to its logarithmic scale but the PPI scope can give very good accuracy especially with a school ruler and a pocket calculator (scope radius is 205mm, target distance is 130mm. 20,000yd * (130/205) = ???).