Skytrak and low launch angles

[Stonebattle]

I've had my Skytrak for over a week now and I find it to be a great device. There are couple of areas that bother me. One is carry distances for my lower launch angle clubs.
For me, that would be the 3 hybrid, 4 metal and driver. I tend to launch each of these at angles of 13 degrees or less. I can hit the driver higher if required but not so much with the others.

The first thing I did with my Skytrak was to get an example of all my club distances in order to not only see what the unit projected, but to check my perceptions. I found the irons might be a bit long but still close. When I got to the 3 hybrid I noticed the carry distance was over 10 yards shorter than I would have thought. My ball speed with my indoor swings are a 1% to 2% lower than outdoors, at least with my driver per Skytrak numbers, so that may be part of it. The launch angles I was getting with a manual launch angle measurement method was a bit lower, but these two still did not explain the shorter carry distances I believed I was seeing.

I decided to take a few swings and the put the average numbers obtained by Skytrak into Flightscope's trajectory optimizer. Skytrak settings were 50% RH, 700 ft ALT and 78 F.
One has to experiment with the numbers in trajectory optimizer a bit to get the results, but here's what I got:

3 Hybrid
Ball Speed - 123.3 --- Launch angle - 11.3 --- Side angle - 2.7 --- Back spin - 2853 --- Side Spin(fade) - 60.7 --- Carry distance -179.7
Trajectory Optimizer --- Carry distance 188.2 or 4.7% more carry

4 metal
Ball Speed - 129.3 --- Launch angle - 10.3 --- Side angle - 1.7 --- Back spin - 2317 --- Side Spin(draw) - 156 --- Carry distance - 188.7
Trajectory Optimizer --- Carry distance 200.2 or 6.1% more carry

Driver
Ball Speed - 138.3 --- Launch angle - 12.1 --- Side angle - 2.6 --- Back spin - 2463 --- Side Spin(draw) - 96.4 --- Carry distance - 217.6
Trajectory Optimizer --- Carry distance 227.4 or 4.5% more carry

To me carry distances are very important because one has to know if one can hit it over an obstacIe. I have found trajectory optimizer to be reasonable in the past and it seems to agree more with my on course experience. I have read quite a bit on line that would not agree with the above, but this is what I'm seeing. I think trajectory optimizer is closer, but I could be wrong.

[FaultyClubs]

Hard to say. The problem is they are both simulations and without knowing where the ball actually landed no-one can't tell which is right.

I can only think of two ways to check skytrak distances with any certainty.

1) Take skytrak to an outdoor trackman session and compare the results on simultaneous hits. Make sure they are both set up properly.

2) Get a buddy and take skytrak to a driving range and measure to ball's landing mark with a good laser rangefinder. At 225 yards someone has to be out in the range marking the ball's landing divot since it is impossible to be accurate from the tee.

Anyone really serious should do both at once to verify the trackman setup.

When looking for 5% errors or better one has to adjust for ground slope, windage,temp, humidity, elevation etc. They also need to try several different balls. Rollout doesn't count, carry only.

With the trackman approach it is possible to compare ball data so see if any differences are due to the Skytrak's measurements or trajectory algorithm.

It's a lot of work so few bother to do it properly. Easier to speculate and rationalize things until they fit our preexisting biases!

[Lawyer]

Seems we have the same trouble. My driver launch angle is between 0 and 3 degrees

[Shardak]

I would not expect 2 different algorithms (Skytrak vs Flightscope) to be much closer than 5%.

If want to boost your skytrak to make it closer to Flightscopes numbers, increase your elevation or temperature and you can get it very close.

[Stonebattle]

Lawyer:
Now that is a low launch angle.

FaultyClubs and Sardak:
I suppose I could adjust the settings to get the low launch angle club distances in line. I did try that and it would mean the 7 iron, for example, would be about a club to long. Also, I believe Trajectory Optimizer calculates distances at sea level while Skytrak's was set to 700 ft, so that would be another yard or so difference. To me if there is a full club difference, something needs to be modified. From the evidence I have, my opinion is that Skytrak needs modification for low launch angles.

[Fieldygolf]

Can anyone advise how they have changed temperature and elevation ie to ehat to get it closer to thrre irl carry distances

[Sledge0001]

When you are at the driving range pull up the session settings by clicking the tab below the battery indicator on the top right of the screen. There you will find the temp, humidity and altitude.