Laser rangefinders are the more accurate ones. As their name suggests they use a laser to measure the distance. They, as previously said, look like binoculars, only with a single lens or a button. If we change our topic for a minute, we could go to the principle of work of the autofocus system on today’s digital cameras. The object which we want to focus is hit by an invisible laser beam which is previously projected from the camera autofocus system. This beam then reflects from the subject and returns to the camera, where it is detected by a sensor in the camera. Meanwhile, a computer chip measures the time it took the beam from leaving the camera, to returning back. When the beam returns, this same chip translates the time to distance, which is, in fact, the distance from the camera to the object which we want to focus on, and what the autofocus system needs in order to adjust. At the start, this technology was a real pain to work with, because it was unreliable and slow. As technology advanced, better autofocus systems started appearing in digital cameras, thus making manual focus cameras old and obsolete. Laser rangefinders work on the same principle, where a laser beam is projected from the device, then hits the target and returns, while the chip inside calculates the time needed and converts that to distance, which it then displays on the small display inside the rangefinder. Considering laser beams move at the speed of light, this technology is incredibly fast, and you will have your readings on the display in a matter of seconds. Some laser rangefinders have a bigger range, but contrary to popular belief, this does not depend on the power of the laser.
GPS rangefinders rely on the Global Positioning Systems. This is a navigation system which is based on a 31 satellites located in space. It provides time and location information anywhere on, or near the earth, regardless of the weather conditions, as long as you have an unobstructed line of view to four or more GPS satellites. The system has been extensively used by the military, but also by commercial users around the world, ever since it was created by the US Government in 1973. The United States make it available to anyone with a GPS receiver. GPS rangefinders are small handheld devices, mostly produced by brands which specialize in such devices, for example Garmin, and work on an immensely different concept than laser ones. Previous GPS devices had great limitations which rendered them pretty much unusable on the golf course, such as not being able to work if not in clear view of the sky, which wasn’t very useful if you got your ball stuck in the trees, and they were restricted to an accuracy of 100 meters which is by no means enough to a golf player. Today’s technological advancements in the field has removed those limitations and GPS rangefinders are as common as laser ones. They basically work by sending a signal to four or more satellites, depending on how many are available and in line of view, and they signal back. After several calculations carried out by the device, it tells you exactly where you are.
Which one would you buy is mostly a personal choice, but be careful and weigh in different options before spending your hard earned money. You can also look for some golf rangefinder reviews and seeing what previous users have to say.