Google has demonstrated new mapping technologies in an effort to reassert its position as a market leader.

谷歌展示了其新式地图技术以借此重夺其市场领导者的地位。

An Android smartphone showcasing the new 3D imagery technology

While it boasts one billion users, Google Maps has recently seen defections by some key developers and partners.

Reports suggest Apple may abandon Google Maps next week at its annual developer conference.

They suggest Apple may announce its own mapping application to replace Google Maps on its smartphones and tablets.

To counteract¹ any negative publicity², Google executives held a media event on Wednesday in San Francisco to preview new mapping features and trumpet³（吹嘘） a decade of achievements in digital mapping, including its use of satellite, aerial（空中的） and street-level views.

Among the stand-out features were 3D enhancements to Google Earth, a portable device for taking "street view" panoramic⁵ photos and offline access to Google Maps on Android phones.

"It's much more than finding a way home," said Brian McClendon, vice⁴ president of engineering for Google Maps.

"Personal helicopter"

Google Imagery, the company's most sophisticated 3D rendering⁶ to date, makes use of an automated⁷ process to generate very detailed⁸ models from 45-degree aerial photos. Google has actually commissioned a fleet of planes to do the job. The end result is zoomable, three-dimensional cityscapes, complete with top and side level views of buildings, streets and landscaping.

Fly-over views of San Francisco's Civic⁹ Center, City Hall, AT&T Ballpark and waterfront（海滨） were shown during Wednesday's demonstration¹⁰.

"We are trying to create magic here," said Peter Birch, program manager for Google Maps, who compared the offering to "Superman wings."

"It's almost as if you are in a personal helicopter hovering¹¹ over the city," he said.

The feature will be available on both Android and iOs devices in a matter of weeks, Mr Birch told the BBC.

He would not be drawn¹² on the possibility of a snag with Apple if Google Maps is de-bundled from Apple's smartphones and tablets: "I can't really speculate on what the rumours¹³ may be… Apple is a good partner of ours.