KM3NeT is a deep-sea infrastructure composed of two neutrino telescopes being deployed in the Mediterranean Sea: ARCA, near Sicily in Italy, designed for neutrino astronomy, and ORCA, near Toulon in France, designed for neutrino oscillation physics. To achieve the best performance, the exact location of the optical modules, affected by sea current, must be known at any time and the timing resolution between optical modules must reach the nanosecond. Moreover, the properties of the environment in which the telescopes are deployed must be continuously monitored because they affect the timing and positioning calibration. KM3NeT is going to deploy several dedicated Calibration Units to meet these calibration goals. Because of the difference in size between ARCA and ORCA, the design of the Calibration Unit is not the same for the two sites. This proceeding describes all the devices, features and purposes of the Calibration Units with a focus on the ORCA Calibration Unit.

KM3NeT 是一个深海基础设施，由部署在地中海的两台中微子望远镜组成：位于意大利西西里岛附近的 ARCA，专为中微子天文学而设计，ORCA 位于法国土伦附近，专为中微子振荡物理学而设计。为了获得最佳性能，必须随时知道光模块受海流影响的确切位置，并且光​​模块之间的时序分辨率必须达到纳秒级。此外，必须持续监测部署望远镜的环境特性，因为它们会影响时间和定位校准。KM3NeT 将部署多个专用校准单元来实现这些校准目标。由于 ARCA 和 ORCA 之间的尺寸不同，两个站点的校准单元的设计并不相同。