WIP - Pure manual targeting ...

vanjast · 02-07-09, 03:01 PM

I'm just throwing together some Doccies and Tables to help those who like 100% 'realism' targeting through their scopes. A little bit of simple maths is required, which is why you're the Captain... right ?

A ship table where all measurements are scaled at 1 Nautical mile - Yes!! .. you're in the navy now

You'd use these measurements for range calculations

When AOB = 90 you can read the ship speed off this table by timing the ship when it passes through X degrees on the scope gradations. When AOB < 90 you scale the timing accordingly. Most accurate measurement are from 0<AOB<45

So a little test using Iowa as our 'guinea pig'.
While the ship approaches, we measure range, from mast height (No AOB) or from shiplength scaled to AOB. Read values off the first pic above.

We measure time it takes to cross 1 degree on the scope. Scale this to AOB, and read speed off the table (2nd pic) above. Punch in all the goodies into the TDC.

Timing..

Aiming/firing Tube 3

Tube three hitting.... PURE MANUAL MODE

Accuracy is fairly consistent over all speed ranges.
Next post will be a link to all the goodies - must just clean it up and add a decent doc

Platapus · 02-07-09, 10:38 PM

Hey Buddy! If you want to sink American ships go back to SH3 LoL

We don't want your kind in the US Navy

I do have a question about your speed chart. Is your chart easier to use then just timing the passage of the target across the stationary hairline of the scope and using the following formula

Speed (kts) = 1.94 x Length of ship (meters) / Time (seconds)

A simple conversion could be made for the ship length in feet (I am a metric type of guy myself). The advantage of this formula is that it is range independent and works pretty good for AoB under 45.

vanjast · 02-08-09, 01:38 AM

Quote:

Originally Posted by Platapus

We don't want your kind in the US Navy

The Village People never convinced me to join the US Navy..

Quote:

Originally Posted by Platapus

Speed (kts) = 1.94 x Length of ship (meters) / Time (seconds)

A simple conversion could be made for the ship length in feet (I am a metric type of guy myself). The advantage of this formula is that it is range independent and works pretty good for AoB under 45.

This looks like it's the same idea except I put it in table format. I'm going to change this to a sliding ruler/circular chart thingy. It looks likes that formula gives an approximate reading, where as I'm looking for 'pinpoint' accuracy

.
This is been geared for RFB where where you hit a ship matters.

Pisces · 02-08-09, 04:20 PM

Quote:

Originally Posted by vanjast

Quote:

Originally Posted by Platapus

We don't want your kind in the US Navy

The Village People never convinced me to join the US Navy..

Quote:

Originally Posted by Platapus

Speed (kts) = 1.94 x Length of ship (meters) / Time (seconds)

A simple conversion could be made for the ship length in feet (I am a metric type of guy myself). The advantage of this formula is that it is range independent and works pretty good for AoB under 45.

This looks like it's the same idea except I put it in table format. I'm going to change this to a sliding ruler/circular chart thingy. It looks likes that formula gives an approximate reading, where as I'm looking for 'pinpoint' accuracy

.
This is been geared for RFB where where you hit a ship matters.

If I understand your second table right you want to measure speed by timing how long the bow (or whatever part) crosses 1, 2, 4, or 8 degrees in the scope? Right? Well, you need a range to the target for that, as a degree at 1nm is smaller than say 4 nm. The 4 collumns alow to correct for this range but would be cumbersome in use. And loose accuracy.

The formula that Platapus gives is as accurate as the identification you make and what's in the recognition manual. And what's really great, range is no issue at all. It is sensitive to your movement though. To avoid that, it requires having the periscope at 0 or 180, and being on course that is just infront of the target bow. You let the target pass an imaginary wall (immovable since you move along it) in the ocean made by the vertical periscope line. The target's own length determines the speed by how long it takes to cross it. Simple as that. No range or AOB to correct for. Only with near-bow and near-aft AOB it is difficult to measure since you can't see the begin and end of the ship as the structures and sides are in the way. But between 20-160 it's usually good. I would say this method is much more 'pinpoint accurate' as the one above.

vanjast · 02-08-09, 05:04 PM

I've changed the whole concept, and am looking at a wheel.
I agree with the other methods, but they require you to keep your scope up for too long, to make a measurement.

What I want to do, is pop the scope up, make a quick bow measurement, down scope and work out all the TDC stuff, punch this into the TDC and then setup the shot. It requires a bit of homework for one person, but they had about 3 or more people doing this.

Another thing, is that if target courses and speed change at the last minute, one doesn't have the time to do 'longtime' measurements.

Pisces · 02-08-09, 07:32 PM

Quote:

Originally Posted by vanjast

I've changed the whole concept, and am looking at a wheel.
I agree with the other methods, but they require you to keep your scope up for too long, to make a measurement.

What I want to do, is pop the scope up, make a quick bow measurement, down scope and work out all the TDC stuff, punch this into the TDC and then setup the shot. It requires a bit of homework for one person, but they had about 3 or more people doing this.

Another thing, is that if target courses and speed change at the last minute, one doesn't have the time to do 'longtime' measurements.

Ok, sliderule wheel is a perfect solution to the calculation.

But, you don't have to watch al the time. Just the time it starts to touch the line and when it's passed. You could take a peek every now an then to see how far it got (to finally pop up at the right tiime). Also, you can do it at long range. But still, what do you consider long? As an example from Sh3 (as I don't know how long the average pacific merchant is): 140m long ship (which would be 460ft or 155yds) at 7 knots takes 39 seconds to cross. If that Iowa is 270m long, at 10knots its taking 52.5 seconds.

If the target's course and speed change you've made a bad move anyhow, since you are likely detected. If not, it's a regular course change and you've got time enough to track and kill it until the next course change. But hey, if you feel like making it complicated, be my guest.

cgjimeneza · 02-08-09, 09:39 AM

this is excellent, Ive got a lot of slide rules (bot ATO and PAC)
but have never had the courgage to go manual

will this include all ships (TMO and or RFB + RSRD flavors)

as you know they add extra ship classes

good idea

but do try with a Kaga next time ok : :rotfl:

Soundman · 02-08-09, 11:15 AM

Good post. I really like that scope you are using with the red lubber line. Where did you find it? A link would be greatly appreciated.

vanjast · 02-08-09, 11:50 AM

Quote:

Originally Posted by Soundman

Good post. I really like that scope you are using with the red lubber line. Where did you find it? A link would be greatly appreciated.

Over here (the 3rd mod) http://www.subsim.com/radioroom/showthread.php?t=147702

It's made for RFB but could still work for TMO. The readme will explain.
Use JSGME to install it with TMO. If it doesn't work - uninstall it.

This is currently an addition to RFB and my RealNav mod (my next trick which is nearly finished - got sidetracked by this). Once complete I'll test with TMO.

02-07-09, 03:01 PM	#1
vanjast Sea Lord Join Date: Jun 2006 Location: Somewhere else now Posts: 1,740 Downloads: 825 Uploads: 4	WIP - Pure manual targeting ... I'm just throwing together some Doccies and Tables to help those who like 100% 'realism' targeting through their scopes. A little bit of simple maths is required, which is why you're the Captain... right ? A ship table where all measurements are scaled at 1 Nautical mile - Yes!! .. you're in the navy now You'd use these measurements for range calculations When AOB = 90 you can read the ship speed off this table by timing the ship when it passes through X degrees on the scope gradations. When AOB < 90 you scale the timing accordingly. Most accurate measurement are from 0<AOB<45 So a little test using Iowa as our 'guinea pig'. While the ship approaches, we measure range, from mast height (No AOB) or from shiplength scaled to AOB. Read values off the first pic above. We measure time it takes to cross 1 degree on the scope. Scale this to AOB, and read speed off the table (2nd pic) above. Punch in all the goodies into the TDC. Timing.. Aiming/firing Tube 3 Tube three hitting.... PURE MANUAL MODE Accuracy is fairly consistent over all speed ranges. Next post will be a link to all the goodies - must just clean it up and add a decent doc

02-07-09, 10:38 PM	#2
Platapus Fleet Admiral Join Date: Oct 2006 Posts: 19,401 Downloads: 63 Uploads: 0	Hey Buddy! If you want to sink American ships go back to SH3 LoL We don't want your kind in the US Navy I do have a question about your speed chart. Is your chart easier to use then just timing the passage of the target across the stationary hairline of the scope and using the following formula Speed (kts) = 1.94 x Length of ship (meters) / Time (seconds) A simple conversion could be made for the ship length in feet (I am a metric type of guy myself). The advantage of this formula is that it is range independent and works pretty good for AoB under 45. __________________ abusus non tollit usum - A right should NOT be withheld from people on the basis that some tend to abuse that right.

02-08-09, 09:39 AM	#7
cgjimeneza Captain Join Date: Jan 2002 Location: Costa Rica Posts: 527 Downloads: 145 Uploads: 0	keep us informed this is excellent, Ive got a lot of slide rules (bot ATO and PAC) but have never had the courgage to go manual will this include all ships (TMO and or RFB + RSRD flavors) as you know they add extra ship classes good idea but do try with a Kaga next time ok : :rotfl: __________________ Pacific Thunder Campaing VIII-Retired www.subsowespac.org "Left on their own, engineers can be dangerous"

02-08-09, 11:15 AM	#8
Soundman Commodore Join Date: Jul 2006 Location: Orlando, Fl Posts: 617 Downloads: 60 Uploads: 0	Good post. I really like that scope you are using with the red lubber line. Where did you find it? A link would be greatly appreciated. __________________ RVAH-9 RA-5C Vigilante at NAS Sanford, Fl 1966 The coolest plane few have heard of!

02-08-09, 05:04 PM	#5
vanjast Sea Lord Join Date: Jun 2006 Location: Somewhere else now Posts: 1,740 Downloads: 825 Uploads: 4	I've changed the whole concept, and am looking at a wheel. I agree with the other methods, but they require you to keep your scope up for too long, to make a measurement. What I want to do, is pop the scope up, make a quick bow measurement, down scope and work out all the TDC stuff, punch this into the TDC and then setup the shot. It requires a bit of homework for one person, but they had about 3 or more people doing this. Another thing, is that if target courses and speed change at the last minute, one doesn't have the time to do 'longtime' measurements.