If you search online today, many previous online reviews of speed radars cut between every shot leaving the true performance unclear.
Below is the first live comparison of five speed radars simultaneously in one continuous take so the actual performance can be seen.
<SPOILER ALERT: RESULTS BELOW>
Here were the results:
We were impressed and proud of the results that Athla delivered.
As a few points of discussion regarding the results…
One might consider whether the Stalker II should be used as the “gold standard” for comparisons. If we were to simply use greatest agreement across radars as a measure – the Stalker still comes out as the winner.
Bushnell turns out to be more accurate than the results initially look on video. The correct speed was typical shown followed by a new speed as the ball landed on the other side (which was lower). This suggests Bushnell was seeing the speed then losing the speed as the ball went out of its upper range. It then saw the ball again as it landed on the other side. In our final calculations, we chose the more accurate reading we saw for the Bushnell.
Though the SKLZ lists tennis as a supported sport, their instructions also say the radar has problems with synthetic covers. Despite trying different angles and distances, we were unable to get better performance than you see.
The PlaySight is likely more accurate than the results suggest. It appears that the Doppler radars and PlaySight are looking at different locations to calculate the speed. The Doppler radars see speeds a few feet from the baseline. The PlaySight is likely calculating speeds by projecting them back to the baseline. This difference would account for PlaySight reporting speeds that were on average 1 mph faster.
We set up Athla Velocity so that it was seeing speeds at the same location as the Dopplers. Once we did the results were extremely consistent.