Xi+ first impression

[Bubba22]

But indoors FaultyClubs a sticker is recommended for better data, right? Can I ask how the units take wind dtc in to account when used outdoors?

[fhann]

The ball data is measured all the time downrange if the ball is not obscured by a hill or other large object(s). Windspeed does not increase nor decrease the ball spin. It affects the flight of the ball because the net affect of windspeed and it's direction induces the ball to perform like the ball either spins more or less because the net drag/lift is is more/less depending upon wind strength and direction. So the ball is measured and its position is recorded. It shows this position, trajectory, etc. as an actual measurement. Flightscope and Trackman have an option to input actual wind and barometric conditions that are being experienced outdoors and the operator can select an option to normalize the ball flight, so the modelling software takes over and produces a ball flight that would occur without wind.

[Clubfitter73]

Strictly speaking the radar doesn't need a sticker, the ball itself generates enough signal return to produce the frequency sidebands needed to measure spin but indoors the time bandwidth product is so low the signal isn't strong enough to be reliably differentiated from noise so they add a radar reflector (ie metallic sticker) to enhance the signal.

Given doppler frequency sidebands are weak relative to the total radar return, the sticker would be critical for measuring spin rate but not so much for the other stuff.

But very strictly spoken the claim that those sidebands are usable have until now not been confirmed. The sideband data resolution in the images I saw are not such that those are usable and the long range ball data and the values presented show problems in determine that data.

[Clubfitter73]

The ball data is measured all the time downrange.

Not that I'm aware of. The ball data is collected all the time but what can be collected diminishes during the flight. From what I understand in outdoor range testing they use a second unit down range facing the robot and by combining the data from both units they are capable of getting all data.

[Clubfitter73]

Can I ask how the units take wind dtc in to account when used outdoors?

It can not take into account wind because it has no idea at what moment the data was skewed by the wind. It can see from the forward flight path prediction and the actual flight path that there is something interfering and it will try taking that influence out of the equation using when using the normalized function as [fhann] mentioned. But again it depends on the quality of the software how good the final normalised result is.

[fhann]

Not that I'm aware of. The ball data is collected all the time but what can be collected diminishes during the flight. From what I understand in outdoor range testing they use a second unit down range facing the robot and by combining the data from both units they are capable of getting all data.

Flightscope will show the outdoor ball flight in one colour when it is capable of tracking the ball outdoors, and switches to a different colour pattern for the remaining ball flight when it is not capable of tracking, i.e. it is estimating the remaining ball flight and rollout.

[Bubba22]

So on a wind day, is the data as reliable a calm day? As well I am infused, given no obstruction does the Trackmsn/Flightscope track the entire length of ball flight downrange, let's say with the driver?

[Bubba22]

The ball data is measured all the time downrange if the ball is not obscured by a hill or other large object(s). Windspeed does not increase nor decrease the ball spin. It affects the flight of the ball because the net affect of windspeed and it's direction induces the ball to perform like the ball either spins more or less because the net drag/lift is is more/less depending upon wind strength and direction. So the ball is measured and its position is recorded. It shows this position, trajectory, etc. as an actual measurement. Flightscope and Trackman have an option to input actual wind and barometric conditions that are being experienced outdoors and the operator can select an option to normalize the ball flight, so the modelling software takes over and produces a ball flight that would occur without wind.

So wind doesn't cause the ball to spin more or less?

[Dax]

So wind doesn't cause the ball to spin more or less?

No, TM has a video that explains this. I will see if I can find it.

[fhann]

On a windy day, the ball flight is what is shown if you do not normalize the data. So you might see shorter shots or longer shots or shots with more curvature depending upon the wind. It might be useful to gauge how much to play for different wind conditions. It is not good for clubfitting. For clubfitting, I desire calm conditions outdoors, but my course rarely has calm conditions. That is why I prefer to do clubfitting indoors, where many of the outside elements have been eliminated.

You asked about wind and ball spin. The ball spins the same whether there is wind or not. It reacts differently in windy conditions because the apparent spin can be increased or decreased.

A good analogy, is to imagine putting a car on a long surface mounted on a train. The car is set in motion and has a speed of say 50 miles per hour but the train is not moving. The car is moving at 50 mph relative to the surface of the train and the earth. Now, imagine the train starts moving in the opposite direction at 20 mph in the opposite direction. The car is still travelling at 50 mph, (unchanged like ball spin), relative to the surface of the runway on the train, and its speedometer still is registering 50 mph, but the car is only travelling 30 mph relative to the earth. This is what is happening in wind conditions with a golf ball. Into the wind, the apparent spin is increased, and a ball balloons plus there is increased drag so the ball speed is decreased. Therefore, this causes shorter and higher shots into the wind and lower/longer shots downwind. Side wind will cause more or less curvature depending upon the spin axis tilt in relation to the amount of side wind.

[Bubba22]

Thanks for the explaination. http://trackmangolf.com/media/5cd060...etter_2014.pdf

[Dax]

Here is the video Bubba.

http://youtu.be/GhdAP9_-Amg

[Dax]

They could use the stronger signal the metal dot is giving. No idea if they would, the TM uses the flight length to determine if you are using the unit indoor or outdoor so maybe they also use that to switch calculations routines. No idea what the FS is doing.

But in general metal dot will, like indoor, make the ball signal to stand out more. Might however be that over the longer flight that metal dot, even if it is very light and thin, skew the down range aerodynamic ball behavior

Maybe hitting several balls with and without metal dot and then compare data would give an indication. It's possible to get the full carry length data set from the TM so maybe there is an indication there in that data set to be found, never tried that.... yet .....

Just a note that TM does not use length of flight to determine indoor or out, it is actually selected on set-up, when you are choosing your target.

[Dax]

So on a wind day, is the data as reliable a calm day? As well I am infused, given no obstruction does the Trackmsn/Flightscope track the entire length of ball flight downrange, let's say with the driver?

According to TM they Measure the full trajectory Of a shot to 400 yards. In terms of the normalization feature, I suspect that the radar units get all the data they need within a short period of time before wind really influences the shot. For instance at this years PGA event in Scottsdale they had a TM set-up that estimate where the ball would land after about 3 seconds and they were able to pinpoint the landing spot very well ( not sure how much time they needed to measure the flight to be comfortable in making the estimate and then calculate and show he result, but I think they showed where the ball would land in about three seconds). Thus, they likely don't need to see much in terms of ball flight in order to complete their normalization calculations.

[Clubfitter73]

Flightscope will show the outdoor ball flight in one colour when it is capable of tracking the ball outdoors, and switches to a different colour pattern for the remaining ball flight when it is not capable of tracking, i.e. it is estimating the remaining ball flight and rollout.

I was refering to the ball data like spin/speed/spin axis. Not just the tracking of it's flight path.