My impression is that the GPS in the iPhone is quite a bit worse than in many other phones. Even Motorola i425, a $40 prepaid phone, works better in some respects. Acquisition times are long -- 20 seconds and longer, compared to about 5-7 seconds on the BlackBerry Pearl. The accuracy is poor. In daily life the location capabilities of the iPhone seem adequate because cell tower triangulation and the wifi database (look up Skyhook on wikipedia) can provide a rough location. Unfortunately we cannot use those as we need better accuracy.
iPhone OS 2.1 will expose speed / heading through the API. It remains to be seen how accurate those will be. The hardware in the iPhone may not have the capability to compute speed / heading directly from GPS signals. If they do the computation in software and rely on position changes over time, the accuracy won't be that good.
My impression is that the GPS in the iPhone is quite a bit worse than in many other phones. Even Motorola i425, a $40 prepaid phone, works better in some respects. Acquisition times are long -- 20 seconds and longer, compared to about 5-7 seconds on the BlackBerry Pearl. The accuracy is poor. In daily life the location capabilities of the iPhone seem adequate because cell tower triangulation and the wifi database (look up Skyhook on wikipedia) can provide a rough location. Unfortunately we cannot use those as we need better accuracy.
iPhone OS 2.1 will expose speed / heading through the API. It remains to be seen how accurate those will be. The hardware in the iPhone may not have the capability to compute speed / heading directly from GPS signals. If they do the computation in software and rely on position changes over time, the accuracy won't be that good.
My impression is that the GPS in the iPhone is quite a bit worse than in many other phones. Even Motorola i425, a $40 prepaid phone, works better in some respects. Acquisition times are long -- 20 seconds and longer, compared to about 5-7 seconds on the BlackBerry Pearl. The accuracy is poor. In daily life the location capabilities of the iPhone seem adequate because cell tower triangulation and the wifi database (look up Skyhook on wikipedia) can provide a rough location. Unfortunately we cannot use those as we need better accuracy.
iPhone OS 2.1 will expose speed / heading through the API. It remains to be seen how accurate those will be. The hardware in the iPhone may not have the capability to compute speed / heading directly from GPS signals. If they do the computation in software and rely on position changes over time, the accuracy won't be that good.
The hardware in the iPhone may not have the capability to compute speed / heading directly from GPS signals. If they do the computation in software and rely on position changes over time, the accuracy won't be that good.