R10 now coming up 20-30 yards short with Irons and driver

The wood post to the right, the back net  (not shown) is 14’ away, Garmin sits on the small platform 7’ back. 

as mentioned above, the gap between the hitting platform and the Garmin platform could be an issue. 

I'm going to move everything 2’ away from the wood post to see if that post provides noise to the radar. 

Backspin is 5185 and Attack Angle is -2.9. 
10.5 driver dialed down 1.5deg to 9.0. 
Launch angle 17.8 deg

Ok, so then You know why Garmin gives You the yardage.

It may be a misread, but if the measurement is correct, the distance calculation is correct based on the high backspin.

Your aoa should be 3-5 degree positive (up), and backspin should be half. That would give You at least 20 yds more carry.

Your feedback is all assuming the readings are correct. Yet on the range, the way this shot felt would result in a ~200 carry and 235 total yards.  I want to find the change to my home outdoor setup that gets the Garmin to show those results.  It is frustrating and futile to play these weekend tournaments when a decent driver shot only registers 175 yards!

No, I'm not assuming the readings are correct. "It may be a misread"..

But it explains what the Garmin is reading.

If the aoa is wrong, and the vla is wrong, and the backspin is wrong, then I would assume the Garmin is tilted forward.

Do You calibrate the unit before a session, it it level?

RCT balls will measure spin, are You using those?

The Garmin is not a 20k usd unit, but in my opinion it is a fantastic device used correctly. I don't like the Garmin Golf app, so I use GSPro. But I haven't really compared the numbers between Garmin Golf app and GSPro, as I can not compare same shot directly. And at my level, comparing 2 different shots makes no sense.

But I definately know that aiming and levelling/calibrating is needed in order to get good results. Garbage in, garbage out. Your swing speed is quite similar to mine, and the Garmin unit gives me spot on distances compared to real life. But I'm using it in a garage with level floor. GSPro calibrates the unit every time, and all is fine.

I believe hitting into a net can cause issues with ball speed dropping slower than hitting into a impact screen. But I don't know how the unit measures ball speed. And in any case vla should not be wrong.

Backspin using a normal ball, not RCT ball, is a calculated metric. And it is based on Your aoa and vla.

And if those are wrong (impossible for me to say of course), then the yardage will be wrong.

Guess my point is that it is probably nothing wrong with the unit as such. But to conclude from there is not easy. Go to SGT discord channel where the discussion is better, and where You will get more replies from other users. I'm playing a bit with a high speed camera in front of the ball, which I believe is the only current way of recording ball strikes. Of course powdering club face is another. I don't really know if I hit the centre, high, low, toe, heel, up or down on the ball. Filming it does.

I will pick up on this again, but currently the course has opened, and I find it still more fun to play real golf than simulated.

Thanks for the discussion and feedback. I’ll hit shots into a screen (painter drop cloth), and will try somehow to get the continuous platform between the Garmin and my hitting mat. Those 2 things may help accuracy.  RCT balls are probably worth trying  

I do calibrate the unit every time. I played today and achieved multiple 230-235 drives on fairly level ground here in Texas. 

I tested with Titleist RCT balls. 
14’ tee to net. 6’6” Garmin to tee

5 shots with normal ball (est spin rates)

5 shots with RCT ball (measured spin rates)

5 shots with 5’ tall drop cloth 

5 shots with 5’ tall drop cloth, RCT balls

( the anomalies were removed in each group; leaving as few as 3 shots 

The RCT ball didn’t improve distances

 The screen/drop cloth didn’t improve the radar performance

next test is to get a continuous surface between the Garmin and the hitting platform…

Remember: this Garmin reads quite well in the flat range- 230-240 yards drives