High-definition map

[3][4] HD maps are often captured using an array of sensors, such as LiDARs, radars, digital cameras, and GPS,[3][5][6] and they can also be constructed using aerial imagery.

[3][9] High-definition maps for self-driving cars usually include map elements such as road shape, road marking, traffic signs, and barriers.

[4][10] Maintaining high accuracy is one of the biggest challenges in building HD maps of real-world roads.

With regard to accuracy, there are two main focus points that determine the quality of an HD map: In areas with good GPS reception it is possible to achieve a global accuracy of less than 3 cm (1.2 in) deviation using satellite signals and correction data from base stations.

This means that the maximum GPS error can be expressed as a percentage of the distance traveled through a GPS-denied area: this value is less than 0.5%.