Large Volume Metrology is essential to many high value industries to go towards the factory of the future, but also to many science facilities for fine alignment of large structures. In this context, we have developed a multilateration coordinate measurement system, traceable to SI metre, and suitable for outdoor measurements or industrial environments. It is based on a high accuracy absolute distance meter developed in-house and shared between several measurement heads by fibre-optic links. Thus, from these measurement stations, multiple distance measurements of several positions of a target can be performed. At the end, coordinates of the heads and of the different target locations are determined using a multilateration algorithm with self-calibration.

In this paper, the uncertainty of this multilateration coordinate measurement system is determined with a consistent metrological approach. First, 13 different sources of errors are listed and quantified. Then, thanks to Monte Carlo simulations, the standard uncertainty on a single absolute distance measurement is assessed to 4.7 μm. This includes the uncertainty contribution of the telemetric system itself, but also the contributions of the mechanical designs of the measurement heads and the target. Lastly, measurements of three-dimensional coordinates of target positions are performed in a control environment, then in a large workshop without temperature control: these measurements validate the uncertainty assessment of the system.

大批量计量学对于进入未来工厂的许多高价值行业至关重要，同时对于许多用于大型结构精细对齐的科学设施也至关重要。在这种情况下，我们开发了一种多纬度坐标测量系统，可追溯到SI米，适用于户外测量或工业环境。它基于内部开发的高精度绝对距离计，并通过光纤链路在多个测量头之间共享。因此，从这些测量站，可以对目标的几个位置进行多次距离测量。最后，使用具有自校准功能的多边定位算法确定头部和不同目标位置的坐标。

在本文中，采用一致的计量方法确定了该多边坐标测量系统的不确定性。首先，列出并量化了13种不同的错误来源。然后，借助蒙特卡洛模拟，单个绝对距离测量的标准不确定度估计为4.7μm。这包括遥测系统本身的不确定性贡献，还包括测量头和目标的机械设计的贡献。最后，在控制环境中然后在没有温度控制的大型车间中对目标位置的三维坐标进行测量：这些测量结果验证了系统的不确定性评估。