National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, USA.
Phys Rev Lett. 2019 Jul 26;123(4):043001. doi: 10.1103/PhysRevLett.123.043001.
To accurately attribute sources and sinks of molecules like CO_{2}, remote sensing missions require line intensities (S) with relative uncertainties u_{r}(S)<0.1%. However, discrepancies in S of ≈1% are common when comparing different experiments, thus limiting their potential impact. Here we report a cavity ring-down spectroscopy multi-instrument comparison which revealed that the hardware used to digitize analog ring-down signals caused variability in spectral integrals which yield S. Our refined approach improved measurement accuracy 25-fold, resulting in u_{r}(S)=0.06%.
为了准确地归因于 CO_{2} 等分子的源和汇，遥感任务需要线强度（S）的相对不确定度 u_{r}(S)<0.1%。然而，当比较不同的实验时，S 的差异通常约为 1%，从而限制了它们的潜在影响。在这里，我们报告了一项腔衰荡光谱多仪器比较，该比较表明，用于数字化模拟衰荡信号的硬件导致了产生 S 的光谱积分的可变性。我们改进的方法将测量精度提高了 25 倍，使 u_{r}(S)=0.06%。
