Generation and use of HD maps

An apparatus comprising:

• a processor unit configured to provide a first high-definition map;
• a sensor unit configured for providing sensor data representing an environmental condition in a periphery of the apparatus;
• a receiver unit configured to receive data representing a second high-definition map;
• wherein the processor unit is configured to fuse the second high-definition map and the sensor data so as to provide the first high-definition map;
• a transmitter unit configured for transmitting a result of fusing the second high-definition map and the sensor data;
• and a command generator unit configured to generate a command signal representing a vehicle control command for a vehicle carrying the apparatus based on the first high-definition map;
• wherein the processor unit is configured to update or refresh a part of the second high-definition map in the first high-definition map for which other data is available;
• wherein the processor unit is configured to receive information indicating a region of interest in the first high-definition map and to provide the first high-definition map so as to comprise a first degree of resolution in the region of interest and to comprise a second degree of resolution in a region outside the region of interest, wherein the first degree of resolution is higher than the second degree of resolution,
• wherein the receiver unit is configured to receive the second high-definition map using a millimeter-wavelength signal and/or to transmit the first high-definition map using the millimeter-wavelength signal.