@article{Bhatt2014,
  author    = {Bhatt, Kaushalendra M.},
  title     = {Microseisms and its impact on the marine-controlled source electromagnetic signal},
  series = {Journal of geophysical research : Solid earth},
  volume    = {119},
  journal   = {Journal of geophysical research : Solid earth},
  number    = {12},
  publisher = {American Geophysical Union},
  address   = {Washington},
  issn      = {2169-9313},
  doi       = {10.1002/2014JB011024},
  pages     = {8655 -- 8666},
  year      = {2014},
  abstract  = {The marine-controlled source electromagnetic method (mCSEM) is employed for studying the electrical characteristics and fluid contents of sedimentary reservoirs. However, the success rate of the method can be improved significantly by finding the sources of electromagnetic noise and addressing the challenge posed by them at larger offsets where the reservoir signal is often weak. I have studied the mCSEM data and reporting an electromagnetic noise. The strength of the noise is observed 1600 times stronger than the seafloor mCSEM signal at 0.1 Hz. Moreover, the noise and the transmitted mCSEM signals are found coherent in interstation recordings. These readings suggest the severity of the noise. The source investigation presuming the observed noise as an infragravity wave failed to match the response. Then, the role of microseisms is investigated. Microseism causes oscillation of the seafloor and produces electromagnetic disturbances by the dynamics of water. I have used various conditions for a proper discrimination of the noise as microseisms. This mechanism is clearly illustrated with the help of a conceptual diagram. The role of the directionality is part of the study, which is argued for having a significant role in the generation of microseisms. In this paper, a new algorithm is presented and is used for calculating the coherency. The algorithm helps in mapping the coherency value simultaneously in time and frequency domains.},
  language  = {en}
}
@misc{IzgiEiblDonneretal.2021,
  author    = {Izgi, Gizem and Eibl, Eva P. S. and Donner, Stefanie and Bernauer, Felix},
  title     = {Performance Test of the Rotational Sensor blueSeis-3A in a Huddle Test in F{\"u}rstenfeldbruck},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {1150},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-51855},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-518556},
  pages     = {22},
  year      = {2021},
  abstract  = {Rotational motions play a key role in measuring seismic wavefield properties. Using newly developed portable rotational instruments, it is now possible to directly measure rotational motions in a broad frequency range. Here, we investigated the instrumental self-noise and data quality in a huddle test in F{\"u}rstenfeldbruck, Germany, in August 2019. We compare the data from six rotational and three translational sensors. We studied the recorded signals using correlation, coherence analysis, and probabilistic power spectral densities. We sorted the coherent noise into five groups with respect to the similarities in frequency content and shape of the signals. These coherent noises were most likely caused by electrical devices, the dehumidifier system in the building, humans, and natural sources such as wind. We calculated self-noise levels through probabilistic power spectral densities and by applying the Sleeman method, a three-sensor method. Our results from both methods indicate that self-noise levels are stable between 0.5 and 40 Hz. Furthermore, we recorded the 29 August 2019 ML 3.4 Dettingen earthquake. The calculated source directions are found to be realistic for all sensors in comparison to the real back azimuth. We conclude that the five tested blueSeis-3A rotational sensors, when compared with respect to coherent noise, self-noise, and source direction, provide reliable and consistent results. Hence, field experiments with single rotational sensors can be undertaken.},
  language  = {en}
}
@article{IzgiEiblDonneretal.2021,
  author    = {Izgi, Gizem and Eibl, Eva P. S. and Donner, Stefanie and Bernauer, Felix},
  title     = {Performance test of the rotational sensor blueSeis-3A in a huddle test in F{\"u}rstenfeldbruck},
  series = {Sensors},
  volume    = {21},
  journal   = {Sensors},
  number    = {9},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1424-8220},
  doi       = {10.3390/s21093170},
  pages     = {20},
  year      = {2021},
  abstract  = {Rotational motions play a key role in measuring seismic wavefield properties. Using newly developed portable rotational instruments, it is now possible to directly measure rotational motions in a broad frequency range. Here, we investigated the instrumental self-noise and data quality in a huddle test in F{\"u}rstenfeldbruck, Germany, in August 2019. We compare the data from six rotational and three translational sensors. We studied the recorded signals using correlation, coherence analysis, and probabilistic power spectral densities. We sorted the coherent noise into five groups with respect to the similarities in frequency content and shape of the signals. These coherent noises were most likely caused by electrical devices, the dehumidifier system in the building, humans, and natural sources such as wind. We calculated self-noise levels through probabilistic power spectral densities and by applying the Sleeman method, a three-sensor method. Our results from both methods indicate that self-noise levels are stable between 0.5 and 40 Hz. Furthermore, we recorded the 29 August 2019 ML 3.4 Dettingen earthquake. The calculated source directions are found to be realistic for all sensors in comparison to the real back azimuth. We conclude that the five tested blueSeis-3A rotational sensors, when compared with respect to coherent noise, self-noise, and source direction, provide reliable and consistent results. Hence, field experiments with single rotational sensors can be undertaken.},
  language  = {en}
}