Periscope ranging seems ridiculous....

[TorpX]

Originally Posted by Rostbef

I'm currently playing:
TMO 2.1
RSRDC 5xx patch 1

I came upon a convoy with a Hiryu type carrier. Couldn't have been a sweeter approach too. Night, decent vis, slight chop on the water. I took a bazillion ranges and charted them. They all looked halfway decent but I could never get a decent speed solution. It varied anywhere from 6 to 10 knots. These were all manual calculations, I never use the button to find it. I took 4 shots. Nevermind that 3 prematurely detonated (not the point of this thread). I missed way behind so he was either much faster or further away than I had ranged him. So I cheated and reloaded. Further ranges showed him almost 700 yards closer. I'm pretty confused. SH 3 always seemed to be much better at periscope ranging. Any mods that work with TMO and RSRDC to fix this?

I agree with Daniel that it is hard to explain a 700 yd error in this case. In cases such as this, it is often helpful to go over the plot and consider where the error lies. In RL, the range estimates were considered to be error prone and the target's course, on the plot, was "faired" to reconcile it with observed data. If the plot shows the target zigging near and far, it is likely your ranges are bad. If the ranges are consistantly too long or short, your mast ht. reference may be off. There is another possibility however; that the target was not on the same course the whole time. This happened to me once. I assumed the observed ranges were in error, when they didn't jive with my plot, and missed with a four torp spread as a result. The point here is a careful study of your plot can yield valuble clues as to what went wrong. Also, how were your Aob estimates?

[Daniel Prates]

Originally Posted by PortsmouthProwler

Do I miss sometimes? Sure, I do. Do I even get killed sometimes? Yup, I do. I wouldn't play a duck shooting arcade game.

Never before have I seen someone compliment this game with such eloquence.

[Pisces]

Originally Posted by PortsmouthProwler

???

100 yards per minute (I assume that is meant) times 60 minutes is 6,000 yards in an hour which is very close to 3 nautical miles an hour, i. e., 3 knots. Unless you meant three minutes...

Three minute plots? Why? More data? The futz factor in the range alone introduces enough error. Personally, I don't like to keep the scope up for very long, it does not pay to advertise.
...

I gather you are not familiar with the 3 minute plotting rule. In 3 minutes a target moving at 1 knot moves about 100 yards. Since the ruler map tool can measure in these units easily many players like to plot in that interval. Just read off the digits it has moved thus far and you know speed after 3 minutes. It's a neat rule to get into manual plotting for beginners. No need to correct for odd time periods and leftover seconds. Simply on the 3rd minute, But I agree, accurate speed, especially when using optical ranging alone, is pretty bad in these short intervals. Averaging the target motion over a longer time is what I would advise at all times to make shot counts. (without spreads I mean)

The futz factor in the range really depends on your position relative to the target. If the AOB is around 90 (on his beam) then the range error leads to a course uncertainty between plots. But when you are infront or behind him, it leads to a uncertainty in how much it moved during the interval.(so uncertain speed) Therefore I like to parallel to his course while keeping on his beam out of sight. Bearing information is then reasonably good to provide a measure of speed. If the time interval is reasonably long for distant targets. And coincidentaly it's pretty much just like your own movement.

[CapnScurvy]

Tell me, is the Hiryu mast height for TMO 2.1 still set at 20 meters, or 65.6 feet tall?

It should read around 37 meters, or 121.4 feet tall.

This is an error in mast height for the stock game going back to when it was first released, and carried on by TMO by using the games file of the original release. UbiSoft patched the Hiryu some time ago to 31 meters mast height, but it still is not correct!

The point is, this target and many others have the mast height so screwed up you couldn't hit it unless you're so close the torpedo has no chance of missing!!

[CapnScurvy]

As a follow up, for those that may not believe the type of mast height error I described in the previous post exists in the game (or one modded into it), I suggest you check for yourself.

Use this "Hiryu Mission Test" to check the accuracy of the Stadimeter using the mast height of the stock game, or the TMO 2.1 mod, or any other mod you choose. It's JSGME compatible, just download it into the "MODS" folder of the Wolves of the Pacific folder and "activate" it like you would any other mod.

The "Hiryu Mission Test" will appear in the "Quick Missions" or "Single Missions" menu heading of the main game screen. Select the "Realism" option heading found along the bottom of the page, and set the options to nothing "enabled" ("zero" realism). This way you will have the game auto targeting provide you the true accurate range of the 8 Hiryu's positioned around the Porpoise class sub. Just read the range off the Position Keeper and keep track of each target at the 8 relative bearing positions around the sub. Then, use the "Escape" key to return to the main menu of the game and "Enable" manual targeting as the only option for running the mission again.

This time pop the periscope up and take a stadimeter reading of the top of the flag mast (actually you won't see the mast, it doesn't exist. Just use the top of the flag where it would have attached to the mast, figuring it has to be there, visible or not). Check the range found in the Position Keeper and compare it to the true actual range you recorded with auto targeting. Do the stadimeter check several times to get a good average of the range. You'll see the stadimeter found range is quite different than the true accurate range (use the sonar to recheck the true accurate range to the targets. You'll find the sonar, when done by you and sent to the TDC/Position Keeper, are exactly the same as the auto targeting range).

This "difference" is caused by several things. The largest being the Mast Height found for the TMO Hiryu (in the Recognition Manual) is off by 17 meters (56 feet) than what it should be. It's too short!! The stock game lists the Hiryu as 31 meters, or 101 feet tall. Still too short. You won't get an accurate range with the stadimeter if the mast height measurement is this far off. What some of you have stated regarding following "procedures in manual targeting" are correct, however the correct procedure does not make up for the inaccuracy of listing the incorrect mast height (or whatever reference position you use for taking a stadimeter reading).

While you're at it, using the stadimeter, check out the difference between the bow target and the stern target Hiryu's. Compare them to the two port and starboard Hiryu's. You'll find a difference in found range of the two front and back targets compared to the two left and right targets. This is a result of the stadimeter not being correctly positioned on the sub model, resulting in different range distances when comparing these bearing positions. A target will have a different range finding due to what relative bearing it happens to be on, even though the target is at the same true distance away from the sub (give or take a couple of meters/yards)! This was not the case in real life. The periscope itself was the starting position for the real life stadimeter function. In the game, this function is done with a separate "camera" view, independent of the sub model's position of the periscope. This independent view is not correctly positioned matching the position of what the stadimeter math equation uses for finding manual range.

Throw in the fact that the stock TBT/Periscope Telemeter divisions (the hash marks found on the scope lens) are not capable of giving the correct measurement due to the "Field of View" not being set correctly, only adds to the manual targeting inaccuracy. If you want to read more, look at this "Optical Targeting Correction" mods "Discussion" section found further down the page. It should show you what's wrong with the game (which no other mod has addressed) and what has been done to correct it (including corrected mast height/reference height measurements).

[Armistead]

I use SCAF with TMO and have no problems with TMO, but did notice the issue before, so I agree.

[CapnScurvy]

Armistead, with what I've found out with the optical issues of the game I'll be the first to admit that SCAF does not correct all the issues it should.

It does correct the "mast height/reference height point" to a degree, but when I found out that the stadimeter is not centered on the different sub models (yep, there's a difference to each class), the corrected measurement could be off depending on "where" the target was positioned when I used the mission test for calculating the stadimeter range.

When I check ships for mast height measurements I usually would put maybe 8 -10 targets around a stationary sub; get a true range from using the auto target option for each ship; then use manual targeting and the stadimeter to give me the manual found range. I have a math formula for correcting the "mast height/reference height position" height measurement, then check the measurement again for accuracy (give or take up to 8 or so meters). Not until recently did I know the stadimeter was not "centered" on the sub to read a range equally around the sub, no matter what relative bearing it was on. This in turn, has made some of the SCAF corrections inaccurate depending on where the target was placed in my mission tests around the sub. If the ship was placed to the port or starboard positions then the corrected mast height is fairly accurate. If the target ship was to the bow or stern of the sub, my correction is inaccurate due to the games stadimeter "centering" problem.

Like I said, I'll be the first to admit it. That's why the "Optical Targeting Correction" mod will be more accurate than SCAF and I would consider SCAF to be obsolete when OTC is finally updated with the corrected mast heights; centering the stadimeter to each sub; correcting the Field of View of the periscopes and TBT/UZO; and correcting the different resolutions the game runs in to provide the same Field of View for all aspect ratio's.

[I'm goin' down]

I can finally get some sleep now!

[Daniel Prates]

I was wondering when captnscurvy would show up, he devoted an entire mod to the Hyriu problem.

[CapnScurvy]

Well, you're right Daniel, reading this topic and seeing the Hiryu as the "main culprit" in the question of range inaccuracy came right into my "wheel house" (sort of speak).

The Hiryu isn't the only ship with a large mast height problem, there are several others, but most are only a couple of meters/yards off, a few within a meter or so. This is using the stock game figures. Various mods change the mast height as well, some because they had a reason. Some for no apparent reason at all. As in the TMO reason, probably due to just an oversight in which file to use? An original, or a newer patched one?

Changing the ship model also effects the manual stadimeter range finding as well. Some mods try to get the ship model to "look" right; some to have it's model "act" right. Changing the "displacement" either has the ship sitting higher or lower in the water. Not having the mast height figure to be corrected to the actual height will produce an error every time.

[Daniel Prates]

This was actually a great discussion we had a few weeks ago. Scurvy, since you started the thread, can't you find the link and post it here? (quite the lazy bum I am).

[CapnScurvy]

This was actually a great discussion we had a few weeks ago.

Hey, it's never to late to learn something!!

Scurvy, since you started the thread, can't you find the link and post it here?

If your talking about the "Optical Targeting Correction" thread? Roll up a couple of replies back (on this page) and mouse over the link I have to the thread. It has the orange color, with the same name.

Guess I'm also too lazy to do it here since, I already have a link to the thread in this one!!

If that's the thread you're talking about?

[0rpheus]

This is a very useful thread to a skipper just trying out manual targeting like me. I've had awful trouble getting an accurate range, to the extent I started aiming the stadimeter deliberately high/low and swapping back and forth between F3/F6 to check until I got the distance right.

Does OTC work with TMO? Sounds like it's exactly what I need If that works, just gotta figure out the AoB and I'll be all set (but that's for a different thread )!

[AVGWarhawk]

Get within in 1500 yards are better. Use the tools for range, AOB and speed. At this range you should be able to get accurate readings for a sinking. You have to remember that approach from a distance is guess work. Get the general direction of the target. Rough guess on speed and range. Start the PK and let the attack begin to develope. When in close the accuracy of your range/AOB can be generated quite easily. Send a spread of 3 torps as was the general rule.

PS. I use TMO. No issues getting range. Get in close and personal.

[AVGWarhawk]

Originally Posted by CapnScurvy

Changing the ship model also effects the manual stadimeter range finding as well. Some mods try to get the ship model to "look" right; some to have it's model "act" right. Changing the "displacement" either has the ship sitting higher or lower in the water. Not having the mast height figure to be corrected to the actual height will produce an error every time.

These are the factors the skippers had to deal with. Many vessel were altered. Mast height was increased or decreased. Laden ships created issues. It was not an extact dead on solution all the time. A lot was good guess work and intuition. Throw in some rough seas and shooting from the hip was called for. Doctrine I believe was 1500 or better to target. This greatly increased the probablity of a hit. Having an accurate mast height figure everytime was not something the skippers had access too.