Re: Spec is missing 'declination' - body's current pointing angle above horizon

Hi Angel,

On Mon, Oct 13, 2008 at 4:39 PM, Angel Machín <angel.machin@gmail.com> wrote:
>
> I think that the point is to find out if this information could be relevant
> or not. The azimuth could be taken from the compass and the elevation angle
> from the accelerometers. So it is something "cheap" to get.

Ok, I understand. I just wanted to make sure it's clear that this API
gives you a geographic location. It doesn't tackle other device
properties. Velocity is there as a convenience and Mathew was right to
point out that we could add some info about the movement on the
vertical axis. But there, I'd propose something like "vertical speed"
(e.g. an app showing how fast is someone going down a ski slope would
likely to be interested in that more than the azimuth).

Device orientation is a different feature altogether and its
interaction with our API is not immediately obvious (e.g. would you
invoke a watchPosition callback as a result of a change in orientation
*only*, etc).

>
> As a comment, the BONDI interface draft contains this information as part of
> the location object. In the Java world, the JSR293 defining the location API
> also includes device orientation when available.
>

Thanks for the data point, it is good to know. Please note that when
we listed our use cases and requirements, we did take a close look at
a lot of other location APIs, including JSR293.

All the best,
Andrei

> What do you think?
>
> Angel
>
> On Mon, Oct 13, 2008 at 4:04 PM, Andrei Popescu <andreip@google.com> wrote:
>>
>> Hi Angel,
>>
>> On Mon, Oct 13, 2008 at 3:45 PM, Machin, Angel, VF-ES (amachin)
>> <angel.machin@vodafone.com> wrote:
>> > Hi Mathew,
>> >
>> >
>> >
>> > Yes, it could be a good idea to have this additional variable that
>> > together
>> > with the heading could be used to calculate a 3D vector corresponding
>> > with
>> > the device's orientation.
>>
>> The existing "heading" property refers to the velocity. It has nothing
>> to do with the orientation of the device, but it refers to the
>> velocity of the device (i.e. direction of travel). Right now, the
>> current API does not aim to provide device orientation information.
>> IMHO, that is a different topic.
>>
>> All the best,
>> Andrei
>>
>
>

Received on Monday, 13 October 2008 16:15:21 UTC