I have a web service that includes mainly data on map. Can Google fetch these data (asynchronously loaded )?
The solution I'm opting right now is to set the data URLs in a regular sitemap, but there is no geolocation information on it.
Yes Google can crawl your images and maps which you have on your website. You can configure these bits of data also with a data highlighter so it gives Google a better knowledge of what it actually is.
If I am right you can also submit maps to Google webmasters now?
Google know alot more about your images and data shown on your map than you think, if you have an image based site maybe you want to get an image xml sitemap?
Google's recommended solution for the problem is crawlable AJAX. You include a meta tag in your page
<meta name="fragment" content="!">
Then Googlebot fetches
http://example.com/map.html?_escaped_fragment_= and expects you to give it an HTML snapshot containing the data that would be shown to users on the map.