Quick Answer: A golf launch monitor works by capturing the ball (and sometimes the clubhead) in the instant around impact using either Doppler radar or high-speed cameras, then running that data through software to calculate ball speed, launch angle, spin, and carry distance. Radar units — like the Garmin Approach R10 (about $599.99) — track the ball’s actual flight over several feet and need real space behind and in front of it. Camera-based photometric units — like the SkyTrak ST MAX (~$2,995) or Foresight GCQuad (from $14,000) — photograph the ball at the moment of impact and calculate everything else from that single frozen frame, which is why they work in much tighter rooms. Shop golf launch monitors on Amazon.
If you’ve been comparing units for a home simulator build, you’ve probably noticed the spec sheets throw around terms like “Doppler radar,” “photometric,” and “stereoscopic” without explaining what any of it means for how the device actually behaves in your garage or basement. This guide breaks down the two core sensor technologies in plain English, so the difference between a $199.99 radar unit and a $14,000 camera rig makes sense before you buy either one.
Launch monitor tech by the numbers
- According to Garmin, the Approach R10 uses Doppler radar to track the ball starting the instant it leaves the clubface, sampling its position repeatedly over the first several feet of flight to calculate ball speed, launch angle, and estimated spin — the same core principle used in weather radar and speed-detection guns, just miniaturized.
- Per Foresight Sports, its photometric units like the GC3 and GCQuad fire infrared strobes and capture the ball’s dimple pattern in a single frozen image at impact, then calculate spin directly from how that pattern is rotated — a fundamentally different (and, per Foresight’s own testing, more spin-accurate) approach than inferring spin from a radar-tracked flight path.
- Radar units need real room to work: FlightScope specifies roughly 16 feet of clearance for the Mevo Gen 2 to get a clean flight-path read, while photometric units like the Uneekor EYE MINI CORE need as little as 2-3 feet, per Uneekor’s own space guidance — the single biggest reason small-room buyers gravitate toward camera-based units even at a higher price.
The two core technologies, side by side
| Factor | Doppler radar | Photometric (camera) |
|---|---|---|
| How it works | Tracks the ball's actual flight path over several feet using radio waves | Photographs the ball's position/dimple pattern at the instant of impact |
| Space needed | 8-18 ft behind/in front of the ball | As little as 2-3 ft in front of the ball |
| Best environment | Outdoors or long indoor bays | Tight indoor rooms and basements |
| Spin accuracy | Estimated from flight-path drift | Measured directly from dimple pattern |
| Typical price range | $199.99-$1,299 (personal units) | $1,499-$23,999 |
| Example units | Garmin R10, FlightScope Mevo Gen 2, PRGR | SkyTrak, Foresight GC3/GCQuad, Uneekor EYE lineup |
Doppler radar: how it actually tracks a shot
Garmin Approach R10
- Sits 6-8 feet behind the ball and tracks it as it leaves the clubface.
- Samples ball position repeatedly over the first several feet of flight to derive speed, launch angle, and carry.
- Estimates spin from how the flight path curves rather than measuring it directly.
Radar-based launch monitors work on the same principle as a weather radar gun: they emit radio waves, measure how the frequency shifts as the ball moves away (the Doppler effect), and use that shift to calculate speed and trajectory. Because the unit needs to track the ball’s actual flight — not just the moment of impact — it needs real distance in front of the ball to get an accurate read, which is why radar units like the R10 and FlightScope Mevo are the natural fit for an outdoor range or a longer indoor bay, and less ideal for a cramped basement corner. The tradeoff for that extra space requirement is a lower price: entry radar units start around $199.99, a fraction of what a camera-based system costs.
Photometric cameras: how they read impact instead of flight
SkyTrak ST MAX
- Fires high-speed strobes to photograph the ball at the exact instant of impact.
- Reads the dimple pattern in that single frame to calculate spin directly, rather than estimating it.
- Needs only a few feet of clearance since it doesn't track ongoing flight.
Photometric units take a completely different approach: instead of watching the ball fly, they photograph it in the fraction of a second around impact using high-speed strobe cameras, then calculate everything — speed, launch angle, spin, and side spin — from how the ball’s position and dimple orientation change between those frozen frames. This is why premium units like Foresight’s GC3 and the Uneekor EYE lineup can sit just a few feet in front of the hitting position and still work — they never need to see where the ball actually goes. The flagship versions of this tech, like the Foresight GCQuad, add a third or fourth camera specifically to also track the clubhead through impact, which is how club-fitting-grade units capture face angle and path data that budget radar units can only estimate.
Which type should you buy?
- Choose radar if you have 10+ feet of room (a garage, backyard, or long basement) and want the lowest cost per accurate ball-speed and carry number — start with our best budget golf launch monitor picks.
- Choose a photometric camera unit if your space is tight, you want directly-measured spin instead of an estimate, or you’re club fitting and need real clubhead data — see our best golf launch monitor roundup for the full range from SkyTrak to GCQuad.
- Either way, plan your space first. Our golf simulator room size guide breaks down exact clearance numbers by sensor type so you don’t buy a radar unit for a room that can’t fit one.
- Compare the field. Our launch monitor comparison table lists the sensor type, data points, and price for every unit we’ve reviewed, radar and camera alike.
The bottom line
Every golf launch monitor solves the same problem — turning a fraction of a second of ball flight into usable numbers — but radar and photometric cameras get there in opposite ways. Radar tracks the ball’s real flight path and needs real space to do it, which keeps entry prices low; photometric cameras read the ball at the instant of impact and need almost no room, which is why they cost more but fit almost anywhere. Match the technology to your space and budget before you shop, then check our best golf launch monitor guide for our top-rated pick in each category. Get your launch monitor in two days — try Amazon Prime free for 30 days — and start comparing radar and camera numbers for yourself.