In 1965, George Miller first applied measurements of the Doppler-shift created in narrowband acoustic signals during
acoustic sensor CPA events to determine the speed of submarine targets. This technique - subsequently confirmed to
provide speed determinations under optimum conditions accurate to one-tenth of one percent - significantly better
than onboard sensors - revolutionized our understanding of the capabilities of Soviet nuclear submarines and the
hydrodynamic characteristics of all submarines such as the non-linearity of turns-per-knot (TPK) values which decrease
with speed because submarine propellers are designed to be most efficient at maximum speed. Examples (previously
posted): 10.25 at 8.01 knots, 9.61 at 14.25 knots and 9.54 at 26.06 knots for the same submarine on the same day;
thank you Ben Wallis, and, when submerged at significant depth, the stability (speed control) of a main propulsion
turbine during a steady-state transit can be as fine as one part in 4000 for 16 minutes. Thank you George Miller.

Although the easiest Doppler speed solutions were derived from events during which the target passed from full-bow to
full-stern, George often used a cosine function to determine speed when frequency values were not available for full
bow-stern aspects.

What brought this to mind is the following statement from the Internet:

"The Cuban Missile, Aroldis Chapman, may have thrown a 105.1 mph fastball in 2010 to set a Major League record,
but, when you correct for radar gun placement, Nolan Ryan's legendary 1974 heater clocked at 100.9 was really the top
speed ever, at a blazing 108.5 miles per hour.Apr 22, 2015"

Correcting for the radar gun placement indicates that the gun was not directly behind the catcher and that the original
value of 100.9 mile-per-hour had to corrected for the angle by which the radar gun was displaced from that direct line:
pitcher to catcher.

108.5 mph is 1.075 times 100.9. That value is the reciprocal of the cosine of 21.5 degrees which is the angle by which
the radar gun was positioned relative to the line between the pitcher’s mound (point of delivery of the pitch) and home
plate. The gun could have been located in the seats behind and on either the first-base or third-base side of the line.

What is surprising is not that this article appeared in 2015, 41 years after Ryan made that pitch but that anyone ever
thought to make that correction.

Ryan was a unique athlete. At the age of 44, he threw his seventh and last no-hitter and struck out 16 men in the process
against the then best hitting team in the majors, the Toronto Blue Jays. He walked one or it would have been a "perfect"
game. He did not begin to rely on his fastball until the late innings. Before that it was a vicious curve that one batter missed
by two feet. At the age of 53, Ryan could still throw a 90 mph fastball.

Really interesting piece of history, Bruce. Thanks.

Nick

Nick:

Regrettably, you are right when you refer to the subject as a bit of history.

I doubt anyone still uses this - and other arcane techniques - to fully exploit
available data.

Bruce

I need to be cautious what I say, but....During my first tour in Kef, 75-78, we had one of those hand held calculators that used small magnetic strips for programs. We obtained a program from the ASWOC which would compute Doppler based speed and it worked great on the rare occasions we could use it with some certainty. At least a few times we were able to refine classification based on resulting TPK.That was hi-tech in those days!