View Single Post
Old 10-04-09, 12:17 PM   #6
goldorak
Admiral
 
Join Date: Apr 2005
Posts: 2,320
Downloads: 0
Uploads: 0
Default

Quote:
Originally Posted by Pisces View Post
I do not know how big the bearing inaccuracies are for each sensor. But you can make best use of it if you beam the contact, and stream the towed array as far as possible.Then the bearings of the 2 sensors are as far apart as possible. If you happend to have your bow and tail line pointed towards or away from the contact then triangulation is useless on it. Then there is no seperation from the contacts point of view.
Yes, you need maximum separation between sensors. Next you must proceed with a minimum speed of 7 knots so as to have the towed array in line with ownship. The bigger the depth difference is between ownship and the towed array the bigger the error in the tma solution.
Last but not least, to get a precise triangulation mark the contact on the towed array and hull or sphere sonar AT THE SAME TIME whenever possibile.
This single rule will simply your solution as you can't even imagine.

Edit : when using triangulation 6 minutes (4 minutes to wait for the first couple of bearing lines + 2 minutes for the second couple of bearings line) is all you need to fix a solution. No need to go into several legs, one is more than sufficient if the contact isn't maneouvering.
goldorak is offline   Reply With Quote