GPS Watches: The SiRFstarIII GPS Chipset

In 2006 Garmin introduced the 205 and 305 Forerunner watches. Both sports watches feature the SiRFstarIII receiver chip.

SiRFstarIII is a GPS chip that is also found in many of the other leading GPS watches.

The main advantage of SiRFstarIII GPS watches is it’s faster signal acquisition time or “time to first fix” (TTFF) and it’s ability to acquire and maintain a lock in densely covered areas such as forests and bushland, canyons and around urban buildings.

Around densely covered areas a GPS receiver receives signals directly from satellites, but also receives reflected signals that have bounced off hard surfaces. Since your GPS determines your position by calculating how long it takes the satellite signal to reach your receiver, these reflected signals are a source of error.

The SiRFstar III has the processing power to adjust for many of these bounced signals and also weaker signals that older chipsets tend to ignore.

The SiRFstarIII also features a 20 channel receiver, which is capable of processing signals of all visible GPS and WAAS satellites simultaneously. Older GPS chipsets use fewer channel receivers.

GPS receivers based on this chipset have routinely performed better than receivers based on other chipsets.

GPS Watches That Feature the SiRFstarIII chip

Series Model
Garmin Forerunner 205 Product Link
305 Product Link
305 Product Link
310XT Product Link
405 Product Link
405CX Product Link
GlobalSat GH-615B/615M Product Link
GH-625M Product Link
Polar RS200G1 Product Link
RS400G1 Product Link
RS800CX Product Link

For more information on GPS sports watches, visit our GPS watches information page.

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