Pixel Watch 5 improves route tracking by combining several layers that do not fit comfortably on a watch. Google uses 3D building models and AI to correct reflected signals in cities, plus a global network of GPS reference stations to account for atmospheric and satellite error.
The watch compresses raw GPS data and sends it to a server for processing before corrected routes reach the Google Health back end. Google says this design avoided a battery-life penalty and was tested across roughly 4,000 miles in open, wooded, and urban environments. Its competitor comparisons remain vendor tests.
The architecture is a useful edge pattern: sensing happens locally, while expensive correction runs elsewhere. That division improves capability on a constrained device but creates a service dependency. Accuracy, privacy, offline behavior, and retention policy all belong in the product contract, not only in the model description.