How to force GPS provider to get speed in android ?

Question

I want speed factor in my GPS application in android. I want to use both network provider and gps provider both to get location updates. But network provider hardly gives speed. While GPS provider provides fix many a times.

1. But is it so that once a fix is found without speed, device will not request for new update until the interval or distance set in requestLocationUpdates changes ? If so, how can I enforce to continue it until I have speed. I found Criteria class, but we can use it only while choosing a provider. I want to use it while obtaining fix. Can I ?

2. Another thing I noticed is sometimes I get speed to be 127 m/s at start, even I am steady then it normalizes to actual speed. Is this a problem of device (tested in G1), or is in general depending on satallite or location ?

3. Does using Criteria while choosing provider, will not provide me location points that do not fit it ? Like if I set criteriaObj.setSpeedRequired(true) , then will I not get points if there is not such availble. As I require position update in any case.

Any suggestions ?

Answer 1

I think your questions about Android location based services are answered in a recent Google I/O session starting at slide 73 of 84 in the slide show pdf.

In particular, the session describes how to implement a back-off pattern that starts out with a lot of location listeners and removes listeners as accuracy improves (at which point your speed calculations would be believable).