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goldorak · 12-15-09, 06:24 PM

In a contact dense environment use all the sensors, including periscope and esm. Try to do tma on surface contacts when you already have to care about possibile enemy subs is just overwhelming. Go to periscope depth and identifiy, classify and do tma on all visibile surface targets. For tma with periscope you only need 2 bearing lines + stadimenter information. It will be good enough. If there are esm signals merge them with the tma info. Idem for active sonar signals (although that could be bad news !!!

).

For sub contacts, if you're using the waterfall display then know this : if the trace of the contact is going away from your course : the contact is on a lag course (this is important because you don't have to do a course change just to find out). Viceversa if the trace of the contact is apporaching your course the contact is on a lead/overlead course (in this case you can't distinguish between the 2 and you must look at the bearing lines in the tma screen).

If the contact changes course you can see it on the waterfall display.
You will see what amounts to half an S, so if the contact was approaching your course before (lead/overlead) you'll see the trace go outwards (so lag), and viceversa. Comon wisedom has it that you can look at the bearing lines just before and just after the course change and have an estimate for the distance. Yes it will work, but without the other information (course) that won't do you any good. And sure as hell you'll get less information than what a previous tma could tell you.

Also if possibile always try tracking a contact on 2 sensors. Merge and triangulate 2 positions -> get precise tma without needing speed estimate and course change maneouvers.

Last but not least :

in a lag course the point of intersection of the bearing lines will always be the MINIMUM possibile distance of the target.
in an overlead (your going faster than him across the los) course the point of intersection of the bearing lines will always be MAXIMUM possibile distance of the target.

Depending on the situation you could always use active sonar.
Not as a primary ASW sensor, but from time to time it comes in handy.

12-15-09, 06:24 PM	#4
goldorak Admiral Join Date: Apr 2005 Posts: 2,320 Downloads: 0 Uploads: 0	In a contact dense environment use all the sensors, including periscope and esm. Try to do tma on surface contacts when you already have to care about possibile enemy subs is just overwhelming. Go to periscope depth and identifiy, classify and do tma on all visibile surface targets. For tma with periscope you only need 2 bearing lines + stadimenter information. It will be good enough. If there are esm signals merge them with the tma info. Idem for active sonar signals (although that could be bad news !!! ). For sub contacts, if you're using the waterfall display then know this : if the trace of the contact is going away from your course : the contact is on a lag course (this is important because you don't have to do a course change just to find out). Viceversa if the trace of the contact is apporaching your course the contact is on a lead/overlead course (in this case you can't distinguish between the 2 and you must look at the bearing lines in the tma screen). If the contact changes course you can see it on the waterfall display. You will see what amounts to half an S, so if the contact was approaching your course before (lead/overlead) you'll see the trace go outwards (so lag), and viceversa. Comon wisedom has it that you can look at the bearing lines just before and just after the course change and have an estimate for the distance. Yes it will work, but without the other information (course) that won't do you any good. And sure as hell you'll get less information than what a previous tma could tell you. Also if possibile always try tracking a contact on 2 sensors. Merge and triangulate 2 positions -> get precise tma without needing speed estimate and course change maneouvers. Last but not least : in a lag course the point of intersection of the bearing lines will always be the MINIMUM possibile distance of the target. in an overlead (your going faster than him across the los) course the point of intersection of the bearing lines will always be MAXIMUM possibile distance of the target. Depending on the situation you could always use active sonar. Not as a primary ASW sensor, but from time to time it comes in handy. Last edited by goldorak; 12-15-09 at 06:57 PM.