Sonar ping distance

BlackSpot · 04-11-07, 05:03 PM

OK. Here's the scenario. I'm all lined up in the path of a large old split freighter. I'm 90 deg to his coarse, all looking good.

I'm an a GAR class (Tambor). Now this maybe a bug on a bug BUT the sonar works at periscope depth. Sonar man is calling out the bearing etc. I ping the range to the target. Answer 3290. Fine. Send that to the TDC. OK 3410. Eh? You just said 3290. Later, pinged distance 1250. Send to TDC, 1390.

Thing was I was trying to estimate the speed by pinging the merchant. Now if the range in the TDC is say 1200 and you ask the sonar man what's the range, and I've got the speed correct in the TDC, he says 1200. As him to send that to the TDC again and it changes. It's always further away.

Thoughts? (or have I got hold of the wrong end of a weasel)

04-11-07, 05:03 PM	#1
BlackSpot Lieutenant Join Date: Mar 2007 Location: Shropshire UK Posts: 266 Downloads: 21 Uploads: 0	Sonar ping distance OK. Here's the scenario. I'm all lined up in the path of a large old split freighter. I'm 90 deg to his coarse, all looking good. I'm an a GAR class (Tambor). Now this maybe a bug on a bug BUT the sonar works at periscope depth. Sonar man is calling out the bearing etc. I ping the range to the target. Answer 3290. Fine. Send that to the TDC. OK 3410. Eh? You just said 3290. Later, pinged distance 1250. Send to TDC, 1390. Thing was I was trying to estimate the speed by pinging the merchant. Now if the range in the TDC is say 1200 and you ask the sonar man what's the range, and I've got the speed correct in the TDC, he says 1200. As him to send that to the TDC again and it changes. It's always further away. Thoughts? (or have I got hold of the wrong end of a weasel) __________________ Do nothing which is of no use.