On Dec 28, 2:50 pm, innivodave <[email protected]> wrote: > I'm trying to figure out the arc seconds per pixel for the current > zoom level, which I would have thought would be the same on the > vertical and horizontal axis, but I seem to be getting different > values.
They are different. The distance along the equator for one degree of longitude is the Earth circumference / 360, while the same measurement taken at the poles is 0. That means that there is no direct equivalence between pixels and degrees of arc. The value changes with latitude. -- Marcelo - http://maps.forum.nu -- > The horizontal value is always the same for a given zoom > level, regardless of map position, but the vertical values changes as > the map position does. This is what I'm doing: > > 1. get bounds using map.getLatLngBounds() > 2. get viewable width by subtracting bounds.getEast() - bounds.getWest > () > 3. multiply viewable width in decimal degrees by 3600 to get viewable > width in arcseconds > 4. divide viewable width in arcseconds by viewable width in pixels to > get arcseconds per pixel. > 5. repeat for height > > Could the problem be something to do with the projection of the map? > > Another thing I noticed is the scaleControl is useless, apparently the > andromeda galaxy is 1 meter across :) but the interesting this is > that the scale changes as the map is moved vertically. Sounds like > this could be related to my issue maybe? > > I'm completely new to this, and figuring it out as I go, so I could be > doing this completely wrong, any help at all would be great. > > Thanks > Dave -- You received this message because you are subscribed to the Google Groups "Google Maps API" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-maps-api?hl=en.
