Verification of Tannar Model with Empirical Trackman Data

 

Trackman is a company that makes a golf ball monitor that uses Doppler Radar to track the golf ball as it flies through the air. It is used by the United States Golf Association, PGA Tour, Royal & Ancient Golf Association, golf club and golf ball manufacturing companies and many golf teaching professionals. It is known as the most accurate golf ball monitor on the market.

Trackman has been publishing some of its empirical results in its newsletters. In its January, 2010, Newsletter, it published PGA Tour and LPGA Tour average statistics for Driver trajectories (Page 6 of Jan 2010 Trackman Newsletter, http://trackman.dk/getmedia/e388effb-0686-425b-9824-650d2e123c6e/January-2010.aspx .

Below in the table you'll find the Trackman data as well as the values predicted by the Tannar Golf Trajectory Model which are outputs of a MS Excel Spreadsheet.

My model assumed a temperature of 25 degrees Celsius (77 F), no wind, near sea level. The Trackman data is accompanied by the note, “ Please be aware that the location and weather conditions haven't been taken into consideration. Besides these reservations the data is based on a large number

of shots and give a good indication on key numbers for tour players.”

Thus, the Trackman data would have been collected at various temperatures, altitudes and wind conditions. Some shots would have been with the wind, some into the wind, and some in a crosswind. Note, that if air temperature is higher and altitude is higher, the ball will carry farther.

 

			Clubhead	Angle of	Ball	Smash	Launch	Spin	Max	Land	Carry
			Speed	Attack	Speed	Factor	Angle	Rate	Height	Angle	Distance
			(mph)	(deg)	(mph)		(deg)	(rpm)	(yd)	(yd)	(yd)
PGA Tour Average
Trackman			112	-1.3	165	1.47	11.2	2685	31	39	269
Tannar Model			112	-1.3	167	1.49	10.3	2374	27	33	259
LPGA Tour Average
Trackman			94	3.0	139	1.47	14.0	2628	25	36	220
Tannar Model			94	3.0	140	1.49	14.5	2043	25	33	215

 

As can been seen from the data, the Tannar Model predicts quite closely the golf ball parameters measured by the Trackman for the two club speeds of 112 mph and 94 mph.

Attached to this report is a print out of the Tannar Model input/output spreadsheet for the 112 mph shot.

 

Legend

Clubhead Speed = the speed with which the club is moving when it impacts the ball

Angle of Attack = the trajectory of the golf club head at impact

e. g. -1.3 degrees means the head of the golf club is moving downwards at 1.3 degrees

Ball Speed = the speed with which the ball moves after impact

Smash Factor = ratio of ball speed to clubhead speed

Launch Angle = angle at which the ball begins travelling upwards after impact relative to horizontal

Spin Rate = the backspin rate of the golf ball after impact

Max Height = maximum height reached by the ball while in flight

Land Angle = angle of trajectory at impact relative to horizontal

Carry Distance = the distance the ball travels horizontally before first bouncing on the ground

 

 

 

and
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