Simulator Altitude Settings

[DeeBee30]

I’ve got a local indoor golf place with several bays that use Foresight GC2s.

The owner (an instructor) told me he sets the altitude/elevation at 1200’ above sea level because it provides results comparable to what we’d normally have mid-summer in Chicago (which sits at about 600’ above sea level).

I didn’t think much of it and proceeded to hit there a couple of times and the distances indicated were pretty spot on with my typical yardages.  I was feeling good about the accuracy of the GC2 until my last session where I was getting about 10% less distance on every club.  

I asked the (different) guy who set me up if there was something wrong with that unit, and he said no.  The owner overheard us and asked the guy if he changed the elevation setting.  Upon checking, the elevation was at the default sea level setting.  After it was changed to 1200’, I was back to normal distances.  

Does it seem right that a launch monitor would need to be set at 1200’ to return the same results that are had in the real world at 600’?  Also, it’s been a long time since I’ve played in Florida, but is it accurate to estimate a 10% difference in distance from sea level to 600’ above?

I found this on the Titleist website, and it seems to indicate the difference shouldn’t be that much:

You can calculate the distance gain you will experience (compared to sea level) by multiplying the elevation (in feet) by .00116. For example, if you're playing in Reno, at 1 mile elevation (5,280 ft.) the increase is about 6% (5,280 x .00116 = 6.1248). If you normally drive the ball 250 yards at sea level, you will likely drive it 265 yards in Reno.

Any knowledgeable insight from anyone?

[Lihu]

GC2 is the most accurate for ball speed. Not sure why Chicago needs a boost? 

Seems like you’re happy with the readings, and that’s all that really counts. As long as the machines are setup consistently, you’ll be able to gauge your progress.

One thing I would caution against is buying a new driver with the settings at 10,000 feet without doing a side by side with your current driver 😁