sonar performance

raduz · 08-06-07, 04:45 AM

This is what I found on wikipedia:
http://en.wikipedia.org/wiki/Sonar

"Sound waves that are radiated down into the ocean bend back up to the surface in great arcs due to the increasing pressure (and hence sound speed) with depth. The ocean must be at least 6000 feet (1850 meters) deep, or the sound waves will echo off the bottom instead of refracting back upwards, and the loss at the bottom reduces performance."

Then why the DDs were able to ping the subs even in shallows water?

switch.dota · 08-06-07, 05:33 AM

Active sonar *should* be less effective at finding a sub in shallow water, especially when the sub is close to the bottom. This is not modelled into the game, however.

John Channing · 08-06-07, 07:05 AM

The operative word there is "reduces"... not eliminates!

JCC

SteamWake · 08-06-07, 10:17 AM

The subs of that era did not have sound absorbing materials applied to their hull. Also they had plenty of 'right angles'. Also they (subs) were typically suspended above the ocean floor. They made a much better uhhhh sound bouncer than the ocean floor.

Sailor Steve · 08-06-07, 10:36 AM

First of all, that portion of the article seems to me to be talking about using sonar to map the ocean bottom. Spotting an underwater object that is much closer to the transponder than the ocean bottom will obtain a echo sooner. Also, anti-submarine sonar never pointed anywhere near straight down. Spotting a submarine in shallow water was more difficult, but not by much. Most difficult was spotting a sub actually lying on the bottom - it was easy to confuse other objects with the intended target.

This might be of some help:

SteamWake · 08-06-07, 11:11 AM

Quote:

Originally Posted by Sailor Steve

Most difficult was spotting a sub actually lying on the bottom - it was easy to confuse other objects with the intended target.

Unfortunatly this does not seem to be modeled in the game. Trust me Ive tried.

08-06-07, 04:45 AM	#1
raduz Engineer Join Date: Sep 2006 Location: Slovakia Posts: 205 Downloads: 3 Uploads: 0	sonar performance This is what I found on wikipedia: http://en.wikipedia.org/wiki/Sonar "Sound waves that are radiated down into the ocean bend back up to the surface in great arcs due to the increasing pressure (and hence sound speed) with depth. The ocean must be at least 6000 feet (1850 meters) deep, or the sound waves will echo off the bottom instead of refracting back upwards, and the loss at the bottom reduces performance." Then why the DDs were able to ping the subs even in shallows water?

08-06-07, 10:36 AM	#5
Sailor Steve Eternal Patrol Join Date: Nov 2002 Location: High in the mountains of Utah Posts: 50,369 Downloads: 745 Uploads: 249	First of all, that portion of the article seems to me to be talking about using sonar to map the ocean bottom. Spotting an underwater object that is much closer to the transponder than the ocean bottom will obtain a echo sooner. Also, anti-submarine sonar never pointed anywhere near straight down. Spotting a submarine in shallow water was more difficult, but not by much. Most difficult was spotting a sub actually lying on the bottom - it was easy to confuse other objects with the intended target. This might be of some help: __________________ “Never do anything you can't take back.” —Rocky Russo

08-06-07, 05:33 AM	#2
switch.dota Captain Join Date: May 2007 Location: Romania Posts: 492 Downloads: 0 Uploads: 0	Active sonar should be less effective at finding a sub in shallow water, especially when the sub is close to the bottom. This is not modelled into the game, however.

08-06-07, 07:05 AM	#3
John Channing Sea Lord Join Date: Sep 1998 Posts: 1,846 Downloads: 163 Uploads: 5	The operative word there is "reduces"... not eliminates! JCC

08-06-07, 10:17 AM	#4
SteamWake Rear Admiral Join Date: Mar 2005 Posts: 13,224 Downloads: 5 Uploads: 0	The subs of that era did not have sound absorbing materials applied to their hull. Also they had plenty of 'right angles'. Also they (subs) were typically suspended above the ocean floor. They made a much better uhhhh sound bouncer than the ocean floor.