Baidu Maps

Within Mainland China • Mainland China Outside Mainland China == History ==

On September 30, 2005, Baidu Maps was released. In 2010, Baidu added a detailed three-dimensional view for select cities, which has been described as being SimCity-like. The feature is licensed from the digital mapping service Edushi. Cities covered include Beijing, Shanghai, Guangzhou and Shenzhen. In November 2011, Baidu launched satellite imagery for the Greater China region with better resolution than Google Maps. City-level only includes Beijing, Shanghai, Guangzhou, Shenzhen, Hong Kong, Macao and other major cities. On September 3, 2012, at its annual Baidu World event, Baidu revealed 360-degree digital imagery for select buildings. == Coordinate system ==

Baidu Maps uses a variant of web Mercator projection for slicing map data into tiles, with distances expressed in degrees. It is associated with an underlying latitude-longitude reference. The reference uses the BD-09 coordinate system, which adds further obfuscation to the already obscure national standard in China, GCJ-02 (which in turn is defined in terms of the de facto standard around the world, WGS 84). Baidu alleges that adopting BD-09 "protects users' privacy". The Baidu Maps API documentation specifies that "real" (WGS 84) GPS coordinates must be converted via a coordinate conversion interface. An HTTP interface, JavaScript API, Android SDK, and iOS SDK are available. The JavaScript coordinate conversion API is demonstrated online by Baidu, but without any reverse (to GCJ-02) conversion capabilities. Open source implementations in R and various other languages exist, implemented in a manner much like the reverse GCJ-02 algorithm. BD-09's latitude-longitude coordinates are derived by scrambling a polar version of GCJ-02 coordinates and adding a fixed offset: from cmath import polar, rect from math import sin, cos, pi • Represent coordinates with complex numbers for simplicity coords = complex • baidu assumes x/real: lon; y/imag: lat here. def gcj_bd(gcj: coords) -> coords: r, θ = polar(gcj) r += 2e-5 * sin(gcj.imag * pi * 3000 / 180) θ += 3e-6 * cos(gcj.real * pi * 3000 / 180) return rect(r, θ) + (0.0065 + 0.006j) ==Street view service==

The street view service of Baidu Maps was first launched on August 21, 2013. This is a list of cities supported as of March 11, 2015: == Blocking ==

India In June 2020, the Indian Government blocked Baidu Maps as well as 58 other Chinese apps, citing national security concerns during the clashes between the People's Liberation Army Ground Force and the Indian Army in the Galwan Valley. == References ==