What is difference between openlayers & openstreetmaps ?
is openlayers made on openstreetmap or vice versa ?
[GIS] difference between openstreetmap and openlayers
openlayers-2openstreetmap
Related Solutions
The documentation doesn't say much about this, but if you examine the script, there is a mousewheel interval option:
/** * Property: interval * {Integer} In order to increase server performance, an interval (in * milliseconds) can be set to reduce the number of up/down events * called. If set, a new up/down event will not be set until the * interval has passed. * Defaults to 0, meaning no interval. */ interval: 0,
This value can be changed by setting the following when declaring map controls:
new OpenLayers.Control.Navigation(
{mouseWheelOptions: {interval: 500}}
);
If you look at the various data sources , you will see that OSM matches very well with Google's Satellite View.
You can check it with this excellent tool from GeoFabrik. Just mouse over various locations, and you will also see the mouse location on the other map.
But when you check Google Maps, and the Google Satellite View, you will see that they do not match.
The best way to observe this, is to open up Google Maps in Hybrid view, where you will see a clear shift between The satellite view and the Roads Layer.
So it is Google Maps, that on purpose are showing incorrect maps.
As to why this is happening, only Google can give you the authentic answer, but my experience says that this must be to meet the statutory requirements of Chinese laws.
A brief reading of The Google forums shows that this issue is well known. For example see these posts:
- Mainland China maps and satellite images aren't aligned - Google can you fix this please?
- major shift between map and satellite view for Shanghai China
More reading indicates that this is done because of the laws of China. See these Blog Posts.
All Maps in China are Transformed (Warning: Firefox & Google claim that the blog has malware. That's why I've linked to it's discussion on HackerNews.)
Update
I have seen that this offset has been attributed to the fact that China uses some other projection. This is utter nonsense.
There are many countries that have their data in other projections as well as datums other than WGS84. Web maps in these regions appear correct, and show no mismatch.
It is hard for me to believe that organisations such Google, Microsoft(Bing maps), Apple & Nokia (Here maps) are stopped in their tracks by a simple datum transformation or projection transformation, when the code for that is easily available in Repositories such as
Further more, when Chinese services such as Baidu can show a correct map, and Foreign services cannot, it indicates that the issues are not just techincal
Best Answer
As the GIS SE tag descriptions note:
OpenStreetMap (OSM) is data
OpenLayers is a client viewer