Author: Rod McAnally
A common question people ask is just how accurate are sports GPS watches?
Many different people will tell you many different things. A common misconception is that GPS measurement is only accurate to within 15 meters (49 feet), which is what the US government and manufacturers of GPS receivers will report, but these days using corrected location data, a much greater level of accuracy is achievable.
Ground stations receive the GPS signals and then provide correction data that is then transmitted to non-GPS satellites – that is satellites that are not part of the GPS network – which is then broadcast to compatible GPS receivers. Two common location correcting networks are differential GPS (DGPS) and Wide Area Augmentation system (WAAS).
Modern GPS watches utilize the highly sensitive SiRFstarIII chipset or equivalent which can link to 20 GPS and non-GPS satellite signals simultaneously. It is compatible with the corrected location data offered by WAAS, which has a specified worst-case accuracy of 7.6m laterally and 7.6m vertically. Independent tests however have proven it to be accurate to within as little as 1.5 meters.
When purchasing a GPS watch, take into consideration whether the watch utilizes a modern chipset like the SiRFstarIII. Legacy GSP watches like the Garmin Forerunner 101, 201 and 301 watches use an older chipset which are less accurate, take much longer to acquire a signal lock and lose the signal far more easily than modern chipset watches. If you are unsure about the chipset of a particular watch model, we feature a complete list of GPS watch chipsets on our website.
Visit our website to learn much more about GPS Watches and other types of sports watches. Check it out here. Digital Sports Watches.
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