选用拉萨台超导重力仪、昆明和恩施台gPhone重力仪以及各台站同址观测的STS-1和STS-2.5地震仪观测数据，计算所有仪器在地震频段（0.1～100 mHz）的噪声水平，并分别进行比较。结果表明，1 mHz以上时，拉萨台超导重力仪噪声水平略高于同址观测的地震仪结果，而1 mHz以下则相反；0.5 mHz以上时，恩施和昆明台gPhone重力仪的噪声水平高于地震仪结果，0.1～0.5 mHz时则与地震仪结果接近。用带通滤波处理和未滤波处理2种方法计算地震噪声等级（seismic noise magnitude, SNM），结果表明，采用带通滤波方法计算得到的SNM值更小，且随月份的变化更加平缓。"/>
In this study, we select one superconducting gravimeter(SG) at Lhasa station, two gPhone gravimeters at Enshi and Kunming stations, and the co-located STS-1 and STS-2.5 seismometers. Noise levels at the seismic frequency band of 0.1 to 100 mHz for these instruments are estimated, and noise levels of instruments at the same site are compared. Numerical results show that the noise level of the SG at Lhasa station is slightly higher than those of the co-located seismometers at the frequency band above 1 mHz, but lower than 1 mHz. The noise levels of gPhone gravimeters at Enshi and Kunming stations are higher than those of the co-located seismometers above 0.5 mHz, and similar at the frequency band of 0.1 to 0.5 mHz. The SNM(seismic noise magnitude) values calculated by two methods with and without bandpass filtering are compared. Results show that, the SNM values calculated with bandpass filtering are smaller and smoother."/>
Comparison of Noise Levels between Gravimeters and Co-Located Seismometers at the Seismic Frequency Band
Abstract In this study, we select one superconducting gravimeter(SG) at Lhasa station, two gPhone gravimeters at Enshi and Kunming stations, and the co-located STS-1 and STS-2.5 seismometers. Noise levels at the seismic frequency band of 0.1 to 100 mHz for these instruments are estimated, and noise levels of instruments at the same site are compared. Numerical results show that the noise level of the SG at Lhasa station is slightly higher than those of the co-located seismometers at the frequency band above 1 mHz, but lower than 1 mHz. The noise levels of gPhone gravimeters at Enshi and Kunming stations are higher than those of the co-located seismometers above 0.5 mHz, and similar at the frequency band of 0.1 to 0.5 mHz. The SNM(seismic noise magnitude) values calculated by two methods with and without bandpass filtering are compared. Results show that, the SNM values calculated with bandpass filtering are smaller and smoother.
LI Hang,CHEN Xiaodong,XU Jianqiao et al. Comparison of Noise Levels between Gravimeters and Co-Located Seismometers at the Seismic Frequency Band[J]. jgg, 2020, 40(8): 843-848.
LI Hang,CHEN Xiaodong,XU Jianqiao et al. Comparison of Noise Levels between Gravimeters and Co-Located Seismometers at the Seismic Frequency Band[J]. jgg, 2020, 40(8): 843-848.
