help: range finding using scales

ichso · 04-08-09, 02:03 AM

Hi there. I'm still quite new to SH4 yet, have played SH1 and SH3 very much in the past. I'm currently using SH4 1.5 with RFB 1.52. I have some slight trouble estimating the target range.
For testing I played a training mission with one ship standing still at ~1000 yards and another one at ~2100 yards. Identification gives me that both are some modern passenger liner ships with 120ft. mast height.
Using the stadimeter says that the closer one is ~1100 yards away. But when I want to use the TBT/Peri-Scales I get results that are a few 100 yards off.

For example: Att.Peri zoomed in, 7 small marks means (as I read from the manual) 1,75°. Then: target range is supposed to be:
range = mast height / sinus(1,75°) = 120 ft. / ~0,03 = ~3929 ft. = ~1300 yards. (At least the range dial says that it is supposed to be yards not NM). The difference between the stadimeter results and mine gets even bigger for the ship which is farther away (there it is ~2100 vs ~2800).

EDIT: after reviewing simple trigonemtry, I think this formula (from SH3 manual) is a bit too simple, you would calculate the hypotenus with it, not the needed adjacent. But doing it more complicated and correctly gives only a slightly better result and the problem remains.

Is this a result of unreliable information in the recognition manual or are the peri scales off ? I got similiar results when using the TBT. Also, it would be nice to enter the range manually without the ship being recognized as identified by the game (the yellow description in the PK console).

04-08-09, 02:03 AM	#1
ichso Ace of the Deep Join Date: Jul 2005 Location: Germany's oldest city alive Posts: 1,066 Downloads: 57 Uploads: 0	help: range finding using peri/tbt scales only Hi there. I'm still quite new to SH4 yet, have played SH1 and SH3 very much in the past. I'm currently using SH4 1.5 with RFB 1.52. I have some slight trouble estimating the target range. For testing I played a training mission with one ship standing still at ~1000 yards and another one at ~2100 yards. Identification gives me that both are some modern passenger liner ships with 120ft. mast height. Using the stadimeter says that the closer one is ~1100 yards away. But when I want to use the TBT/Peri-Scales I get results that are a few 100 yards off. For example: Att.Peri zoomed in, 7 small marks means (as I read from the manual) 1,75°. Then: target range is supposed to be: range = mast height / sinus(1,75°) = 120 ft. / ~0,03 = ~3929 ft. = ~1300 yards. (At least the range dial says that it is supposed to be yards not NM). The difference between the stadimeter results and mine gets even bigger for the ship which is farther away (there it is ~2100 vs ~2800). EDIT: after reviewing simple trigonemtry, I think this formula (from SH3 manual) is a bit too simple, you would calculate the hypotenus with it, not the needed adjacent. But doing it more complicated and correctly gives only a slightly better result and the problem remains. Is this a result of unreliable information in the recognition manual or are the peri scales off ? I got similiar results when using the TBT. Also, it would be nice to enter the range manually without the ship being recognized as identified by the game (the yellow description in the PK console). __________________ My Subskins: http://www.subsim.com/radioroom/showthread.php?t=164169 Last edited by ichso; 04-08-09 at 04:14 AM.