High-definition map

A high-definition map (HD map) is a highly accurate <a href="/facts/Map/KxQX4B2U">map</a> used primarily in the field of <a href="/facts/Self-driving_car/KXeFywXS">autonomous driving</a>, containing details not normally present on traditional maps. HD maps are often captured using an array of sensors, such as <a href="/facts/LiDAR/b9SPUmLM">LiDARs</a>, <a href="/facts/Radar/jk9BTbFA">radars</a>, <a href="/facts/Digital_camera/LSGTserm">digital cameras</a>, and <a href="/facts/GPS/DKVLnzF3">GPS</a>, and they can also be constructed using <a href="/facts/Aerial_imagery/Sp9D0crM">aerial imagery</a>. Such maps can be precise at a centimetre level.
High-definition maps for self-driving cars usually include map elements such as road shape, <a href="/facts/Road_surface_marking/yk8thLtL">road marking</a>, <a href="/facts/Traffic_sign/yfn9b7Uf">traffic signs</a>, and barriers. 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:

<ul><li>Global accuracy (positioning of a feature on the surface of the Earth).</li>
<li>Local accuracy (positioning of a feature in relation to road elements around it).</li></ul>
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.
In GPS-denied areas, however, inaccuracy rises with distance traveled through the area, being largest in its middle. 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%.

High-definition map open-in-new

High-definition map