- From: Steve Block <steveblock@google.com>
- Date: Mon, 16 May 2011 17:06:32 +0100
- To: Dean Jackson <dino@apple.com>
- Cc: public-geolocation@w3.org
Hi Dean, Thanks for your comments. I understand the problem you describe, but I'm not sure that moving the absolute heading to a different property is the right solution. > However, I think that we should NOT require the alpha to be a compass heading, So how would you define alpha? I think you're suggesting that alpha should only be determined from a gyroscope, but the idea of the spec is to be independent of the underlying source of data. The UA should use whatever data sources it has to provide the best possible values to JavaScript. > All of a sudden, the compass decides that my heading has changed (a source of interference has been removed). > What should the system do? If it changes the DeviceOrientation events, the player might jump off a cliff even > though I didn't move. But it can't ignore the change in heading. If the UA has access to both a gyroscope and a compass, I'd expect it to filter the two sets of the data to take advantage of the increased accuracy of the gyroscope while using the compass data to counter drift in the gyroscope data. This should avoid the value of alpha jumping around due to compass noise. Have you tried this? If the UA has only a compass, I don't think there's any way to avoid the problem. Steve -- Google UK Limited Registered Office: Belgrave House, 76 Buckingham Palace Road, London SW1W 9TQ Registered in England Number: 3977902
Received on Monday, 16 May 2011 16:06:57 UTC