|Why does Google maps use the inaccurate, ancient and distorted Mercator Projection?||jfricker||8/3/09 10:49 PM|
Dear Google Maps,
Every time I see a "Powered By Google" website display the default Google world map, I wince and wonder "why does the most sophisticated information technology company in the world use the most distorted and archaic world map known to humankind?".
The Mercator Projection distorts the world, giving the false impression that Greenland is the size of South America, Asia is ginormous and Alaska is bigger than Mexico - all inaccuracies that are being presented by Google. Google's reputation for accuracy means that these distortions are reinforced in our conscience as facts.
The Mercator Projection is 440 years old and provided one practical purpose - bearings can be accurately drawn. The utility of this begins and ends with nautical navigation - clearly not the primary purpose of Google maps.
I urge Google to be responsible with the world's knowledge and follow the advice of numerous cartographic associations that request that the Mercator Project not be used. For anything. Ever.
Many viable alternatives are available, including the Winkel Tripel projection which is the modern standard world map adopted by the National Geographic Society.
Is it not time for Google Maps to come forward, at least to the 20th century?
|Re: Why does Google maps use the inaccurate, ancient and distorted Mercator Projection?||Joel H||8/4/09 12:27 PM|
|Re: Why does Google maps use the inaccurate, ancient and distorted Mercator Projection?||Limerick||9/26/09 4:54 AM|
Would it be possible to add to Metric and Statute Mile (=1609 meters), the possibility to choose Nautical Mille (=1852 meters).
It's the maritime and aeronautic measure unit and it is used for long distance (around earth...).
It should be very easy to code this (almost a simple copy-paste) and to put it on the left part where there is enough room.
|Re: Why does Google maps use the inaccurate, ancient and distorted Mercator Projection?||ticktrader||12/10/09 2:37 PM|
That is the most ridiculous response I've heard. It's a computer, you tell it what to do not the other way around. Your zoomed out projection of the world should use accurate projections and then switch to angle preserving projections as you zoom in.
|Re: Why does Google maps use the inaccurate, ancient and distorted Mercator Projection?||startswithj||12/19/09 10:02 AM|
Would it not be possible to use Mercator projection for city-level viewing, and use a more realistic, respectful projection such as Winkel Tripel for global-level viewing? Perhaps their might be a formula for transitioning between the two?
I agree very strongly that Mercator projection is offensive, irresponsible, and embarrassing. It should be shelved rather than revived and perpetuated.
|Re: Why does Google maps use the inaccurate, ancient and distorted Mercator Projection?||dawalker||12/22/09 2:44 PM|
Projections such as Winkel Tripel are great for showing a single, static image. But even if it could be interpolated into a conformal projection at close zooms, panning the map wouldn't work right. One option would be to pan the whole image, which would look very silly and make areas near the dateline unusable. The other option would be to try to re-center the projection. But if you're doing that, then essentially you've got Google Earth with a weird projection. At that point it makes much more sense to just use Google Earth.
|Re: Why does Google maps use the inaccurate, ancient and distorted Mercator Projection?||TeslaFtw||9/3/10 9:30 AM|
all switch to quantum computers
|Re: Why does Google maps use the inaccurate, ancient and distorted Mercator Projection?||VZoc||3/7/11 1:50 PM|
I'm taking a skipper course and will take the exam next Saturday. The Mercator projection is used by default for navigation and I'm glad to have been able to fiddle about while studying.
My take is that maps are primarily used for navigation and that therefore Mercator maps are so popular. Teaching comes a very distant second and while there are projections that are more "fair" than Mercator, you should always take into account that it remains jolly hard to project a sphere onto a 2 dimensional medium.
I wonder whether a conversion between projections is easily possible. And by "easily" I mean that CPU usage around the globe wouldn't sky rocket for the sake of a nicer projection.
|Re: Why does Google maps use the inaccurate, ancient and distorted Mercator Projection?||PatHadley||6/4/11 12:35 PM|
I understand your answer for the needs of the Google Maps environment - and that its actually quite a tricky computing problem to make a smooth transition during zooming.....
However, the fact that the Spherical Mercator has been transposed onto Google's data visualisation maps such as those on Google Analytics, the Google Chart tools and other products that use the API seems a little harder to explain.....
Any ideas when there might be progress on this?
PS I'll still use the tools as they are head and shoulders above anything anyone else is building!
|Re: Why does Google maps use the inaccurate, ancient and distorted Mercator Projection?||WhiteRabbit||9/13/11 2:27 AM|
By certain measures, such as area, the Mercator map is probably the most distorted, so the question is legitimate. All projections from a sphere to a plane are, of course, distorted. When you fix one kind of distortion, you increase another kind of distortion. The choice of projection, then, is about selecting what kind of distortion you would dislike the least. For example, if it is important to you that areas of countries are shown accurately, an equal-are projection is certainly preferable. The Mercator projection seems at first glance to be an odd choice because it's solution to latitudinal distortion is to make sure that longitudinal distortion is just as bad.
The primary purpose of Google Maps is to provide local navigation, street maps and directions, rather than to provide a planetary view of the Earth. Within the context of local street searches (e.g. where is the closest shoe store), angles and compass directions are very important, as well as ensuring that distances in all directions are shown at the same scale (locally). Consistent area is less important, since local scale is easily dealt with by providing a distance indicator (assuming the region being viewed is relatively small). Also, it is highly advantageous to make panning work correctly in conjunction with zooming, without the application of linear or non-linear transforms. It turns out that there is exactly one kind of planar projection with these properties. That projection is the Mercator projection. The choice to use this projection is not arbitrary, but rather is motivated by practical mathematical considerations. These properties make Mercator the standard for nearly all navigation applications.
A good alternative to Mercator is to not use any projection at all (i.e. map all the data to a three dimensional mesh). This is what Google Earth uses, and it is great for large scale (e.g. planetary) geological applications.
VZoc wrote: "I wonder whether a conversion between projections is easily possible. And by "easily" I mean that CPU usage around the globe wouldn't sky rocket for the sake of a nicer projection."
Yes, these conversions are easy for a computer. However, any alternative to Mercator will remove certain properties such as the ability to pan continuously such that only the newly exposed map needs to be redrawn.