Geoscientific Instrumentation,
Methods and Data Systems 

Current borehole receivers only measure a single parameter of the magnetic field component, which does not meet the special requirements of controlled-source electromagnetic (CSEM) methods. This study proposes a borehole electromagnetic receiver that realizes synchronous acquisition of the vertical electric field component and three-axis orthogonal magnetic field components. Results of the experiments show that our system functioned adequately and that high-quality CSEM signals were obtained.

The Blue Nile Basin is of vital importance for the whole Nile Basin. The investigation of the impact of climate change on this basin is essential. The Blue Nile Basin annual and monthly temperatures were investigated. Spatial and temporal patterns of changes in extreme temperatures are investigated using 10 meteorological stations' data for the period 1950–2018. The investigation showed that climate change increased temperatures in the basin.

A new multicomponent electrical field observation system based on an autonomous underwater vehicle (AUV) was introduced for the measurement of seafloor self-potential. The system was tested in a lake and the multicomponent self-potential data were collected. The new SP system can be applied to marine SP observations, providing an efficient and low-noise SP acquisition method for marine resources and environmental investigations.

The systematic error of calibrated fluxgate magnetometer data is studied for a spinning spacecraft. The major error comes from the offset uncertainty when the ambient magnetic field is low, while the error represents the combination of non-orthogonality, misalignment to spacecraft reference direction, and gain when the ambient field is high. The results are useful in developing future high-precision magnetometers and an error estimate in scientific studies using magnetometer data.

UAV-borne magnetometry has gradually become an important tool for geophysical studies. However, developing such a UAV-borne aeromagnetometry system is challenging owing to strong magnetic interference introduced by onboard electric and electronic components. One static and two dynamic experiments were conducted to understand the platform's magnetic interference. The results reveal that the strongest magnetic interference is from some current-carrying cables.