Bearing Rates and the Nav Map

SeaQueen · 09-21-06, 06:55 AM

Hey Guys!

I think I've finally figured out how to make use of the bearing rate indicator on the nav screen for targets.

In order to do better TMA, I've started keeping a manual bearing rate. My spread sheet calculates it automatically, I just have to put in times and bearings. It just does a quick least squares fit to a line. I read the correct coefficient, and that's the best estimate of my bearing rate.

The thing is...

When my firing solution is really close to where my target is, the bearing rate I calculate by hand, equals the bearing rate calculated by DW on the nav map. So... I can use that to have a pretty good estimate of how well I'm doing on the TMA screen. There's actually a geometrical reason for this, because I think I understand how DW calculates the bearing rate it displays. It's just the target's relative speed across the bearing divided by his range, according to what you put in as your firing solution.

For those not up to curve fitting, it's probably sufficient to just take a ruler and some graph paper, plot time v. bearing, and read the slope of the line.

09-21-06, 06:55 AM	#1
SeaQueen Naval Royalty Join Date: Jun 2005 Location: Washington, DC Posts: 1,185 Downloads: 0 Uploads: 0	Bearing Rates and the Nav Map Hey Guys! I think I've finally figured out how to make use of the bearing rate indicator on the nav screen for targets. In order to do better TMA, I've started keeping a manual bearing rate. My spread sheet calculates it automatically, I just have to put in times and bearings. It just does a quick least squares fit to a line. I read the correct coefficient, and that's the best estimate of my bearing rate. The thing is... When my firing solution is really close to where my target is, the bearing rate I calculate by hand, equals the bearing rate calculated by DW on the nav map. So... I can use that to have a pretty good estimate of how well I'm doing on the TMA screen. There's actually a geometrical reason for this, because I think I understand how DW calculates the bearing rate it displays. It's just the target's relative speed across the bearing divided by his range, according to what you put in as your firing solution. For those not up to curve fitting, it's probably sufficient to just take a ruler and some graph paper, plot time v. bearing, and read the slope of the line. Last edited by SeaQueen; 09-21-06 at 07:00 AM.