making turns for 15 knots

vincent p. norris wrote:
The secret squirrel part is how do you find out the blade rate to
knots correlation of everyone else's submarines.


Well, ATC can give a pilot a groundspeed readout based on tracking his
progress on the radar screen. Can't something of that sort be done
with subs?

As in time-distance using two or more fixes, yes. I think the old
fashioned way was with a piece of paper, but it is nothing for a
primitive (by today's standards) computer to do it for you with two
or several fixes.

Or could the Doppler effect be used for that purpose?

Also yes, but of course if the target is not heading directly (or
near directly) towards or away from your receiver, then doppler shift
will be less pronounced. You can sanity check the "big picture"
using, among other things, doppler, fixes, and common sense.

Last, a lot of the time you only have some of the above information,
the fixes may have questionable accuracy, so then you get an
approximate solution.

Today ou can hear another ship (prop) a hell of a lot farther away than you
can get an accurate fix on it. Although in WWII the equipment wasn't that
developed, it was probably true then also.

Diamond Jim

Ended up in Colorado because of company move so didn't cost us a dime.
House now paid off; good place to live except dry; Rockies 30 miles
away. Wx is pretty good about 90 percent of the time (about 330 days
it's good enough for VFR flight!). Plus a lot of inertia. We do get
down to Corpus Christi/Port Aransas every year).
Walt BJ

wrote in message
oups.com...
Ended up in Colorado because of company move so didn't cost us a dime.
House now paid off; good place to live except dry; Rockies 30 miles
away. Wx is pretty good about 90 percent of the time (about 330 days
it's good enough for VFR flight!). Plus a lot of inertia. We do get
down to Corpus Christi/Port Aransas every year).
Walt BJ


Agreed that Colorado is a good place to live (and my weather is better than
Walt's).

Tex Houston

In article ,
Jim Carriere writes:
vincent p. norris wrote:
The secret squirrel part is how do you find out the blade rate to
knots correlation of everyone else's submarines.


Well, ATC can give a pilot a groundspeed readout based on tracking his
progress on the radar screen. Can't something of that sort be done
with subs?

As in time-distance using two or more fixes, yes. I think the old
fashioned way was with a piece of paper, but it is nothing for a
primitive (by today's standards) computer to do it for you with two
or several fixes.

An interesting thing about all that Target Motion Analysis jazz is
that in some ways, the old analog "Iron Idiots" were better at it than
the modern digital numerical computers. You'd crank in the inital
observed estimates, and see if the Fire Control System's generated
solution matched the target. If it didn't, you'd fudge this & that
(Target bearing & speed, for example, or range if the speed was known)
until it was tracking smoothly.


--
Pete Stickney

Without data, all you have are opinions