We used teleseismic P and S waves recorded in the course of the 2016 Incorporated Research Institutions for Seismology (IRIS) community‐planned experiment in northern Oklahoma, to estimate amplitude correction factors (ACFs) and orientation correction factors (OCFs) for the gradiometer’s three‐component Fairfield nodal sensors and two other gradiometer‐styled subarray nodal sensors. These subarrays were embedded in the 13 km aperture nodal array that was also fielded during the 2016 IRIS experiment. The array calibration method we used in this study is based on the premise that a common wavefield should be recorded over a small‐aperture array using teleseismic observation. In situ estimates of ACF for the gradiometer vary by 2.3% (standard deviation) for the vertical components and, typically, variability is less than 4.3% for the horizontal components; associated OCFs generally dispersed by 3°. For the two subarrays, the vertical‐component ACF usually vary up to 2.4%; their horizontal‐component ACFs largely spread up to 3.6%. OCFs for the subarrays generally disperse by 6.5°. ACF and OCF estimates for the gradiometer are seen to be stable across frequency bands having high signal coherence and/or signal‐to‐noise ratio. Gradiometry analyses of calibrated and uncalibrated gradiometer records from a local event revealed notable improvements in accuracy of attributes obtained from analyzing the calibrated horizontal‐component waveforms in the light of catalog epicenter‐derived azimuth. The improved waveform relative amplitudes after calibration, coupled with the enhanced wave attribute accuracy, suggests that instrument calibration for amplitude statics and orientation errors should be encouraged prior to doing gradiometry analysis in future studies.

中文翻译：

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校准 2016 年 IRIS 波场实验节点传感器的幅度静态和方向误差

我们使用在 2016 年俄克拉荷马州北部地震学联合研究机构 (IRIS) 社区计划实验过程中记录的远震 P 波和 S 波，来估计梯度计的三轴振幅校正因子 (ACF) 和方向校正因子 (OCF)。组件 Fairfield 节点传感器和另外两个梯度计式子阵列节点传感器。这些子阵列嵌入在 13 公里孔径节点阵列中，该阵列也在 2016 年 IRIS 实验期间部署。我们在本研究中使用的阵列校准方法的前提是使用远震观测在小孔径阵列上记录共同波场。对于垂直分量，梯度计的 ACF 的原位估计值变化 2.3%（标准偏差），通常变异性小于 4。3% 为水平组件；相关的 OCF 通常分散 3°。对于两个子阵列，垂直分量 ACF 通常变化高达 2.4%；他们的水平分量 ACF 主要分布到 3.6%。子阵列的 OCF 通常分散 6.5°。梯度计的 ACF 和 OCF 估计值在具有高信号相干性和/或信噪比的频带上是稳定的。对来自本地事件的校准和未校准梯度计记录的梯度测量分析显示，根据目录震中衍生的方位角分析校准水平分量波形所获得的属性精度显着提高。校准后改进的波形相对幅度，加上增强的波形属性精度，