We present a robust, transportable ${\mathrm{Ca}}^{+}$ optical clock, with a systematic uncertainty of $1.3\times {10}^{-17}$ limited by the black-body radiation (BBR) field evaluation and an uptime rate of $>75\%$ over a 20-day period. The clock is then installed in an air-conditioned car trailer, making it more convenient for applications. Referenced to a stationary laboratory clock, geopotential measurements are made with the transportable clock with a total uncertainty of 0.33 m (statistically 0.25 m and systematically 0.22 m) and agree with the spirit level measurement. After being moved $>1200$ km, the absolute frequency of the ${\mathrm{Ca}}^{+}$ optical clock transition is measured as 411 042 129 776 400.41(23) Hz, with a fractional uncertainty of $5.6\times {10}^{-16}$, which is about one order of magnitude smaller than our previous measurement. The transportable built can be used for sub-meter-level elevation measurements, comparing intercontinental optical clocks, verifying basic physical theories, etc.

中文翻译：

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强大的可运输Ca +光学时钟进行地势测量

我们提出了一个健壮，可运输 ${钙}^{+}$ 光学时钟，系统不确定性为 $1.3\times {10}^{-17}$ 受黑体辐射（BBR）现场评估和正常运行时间的限制 $>75％$在20天的时间内。然后将时钟安装在装有空调的汽车挂车中，使其更便于使用。参照固定的实验室时钟，使用可移动时钟进行地势测量，其总不确定度为0.33 m（统计上为0.25 m，系统上为0.22 m），并且与水平仪测量值一致。被搬走之后$>1200$ km，绝对频率 ${钙}^{+}$ 光学时钟跳变的测量值为411042129776400.41（23）Hz，不确定度为 $5.6\times {10}^{-16}$，比我们之前的测量值小一个数量级。可运输的建筑物可用于亚米级海拔测量，比较洲际光学时钟，验证基本物理理论等。