However you plan to use your golf launch monitor, space is going to be a key factor in you purchasing decision. Especially if you are buying it for a home golf simulator setup.
Generally, outdoors, you either need to place the launch monitor unit a designated amount of feet behind the tee (usually for doppler radar-based devices) or next to the tee (photometric golf launch monitors) with unlimited flight space.
But at home—either outdoors hitting into a net or indoors—you'll need to know how much space you launch monitor requires from tee to unit and how much flightspace to net or impact screen is required fro the device to get a good read on the ball.
If you're building a garage golf simulator or a studio inside your house, you'll also need to think about room dimensions.
This post gets you familiar with the space requirements for all of our favorite golf launch monitors with—with and without simulation.