Preprints  

Global satellite navigation systems are commonly used for timing and synchronization of instrument platforms. These system clocks periodically roll over from limitations in discrete counter math. Due to the rarity of these events (19.6 years for GPS), special consideration must be given to designing instruments intended for use in hard to reach locations like the Antarctic Plateau. A few best practices are presented to prevent total system failure from unexpected subsystem faults.

The transient electromagnetic method (TEM) is widely used for mapping subsurface resistivity structures but data are inevitably contaminated by noise from various sources including radio signals in the very low frequency (VLF) 3–30 kHz band. We present an approach where VLF noise is effectively suppressed with a new post-processing scheme where boxcar gates are combined into semi-tapered gates. The result is a 20 % increase of depth of investigation for the presented test survey.

The daily variation amplitude of geomagnetic component Z could represent the diurnal variation strength of geomagnetic field. The ionospheric conductivity, neutral wind in ionosphere and the complicated underground electrical structures make combined action to effect the feature of the Z daily variation amplitude in China. This paper will provide the background information or reference to researchers who study the geomagnetic diurnal variation or to analyse the anomaly.

This paper presents a novel method for locating magnetic interference sources on unmanned aircraft systems (UAS) destined for aeromagnetic surveys. The technique is demonstrated in an indoor laboratory whereas most magnetic mapping has previously been done outdoors and is performed on 4 different types of UAS with their motors engaged. Sources are discussed on each UAS platform, but can also be used as a point of reference for typical components that cause interference.

This study proves how the experimental results coincide with theoretical factors of LE-PIXE in case of High Grade Metamorphic Rocks and calibration of Si (Li) detector in case of low Z elements for future research. The Experimental parameters behind the low Z elements and also the developments of the same LE-PIXE by alter the various parameters and the complementary techniques which will be required for low energy X-rays emitted from low Z.

Laser interference absolute gravimeters are high-precision gravimetry instruments. However, The error caused by self-sysetm and enviromental vibration has become the primary obstacle limiting its accuracy and stability. The present work addresses this issue by proposing a global search optimization algorithm that determines the optimal absolute value of gravity. The results evaluated by numerical calculations demonstrate that this algorithm provides a substantial anti-vibration capability.

Analysis of non-uniqueness model in resistivity imaging data is vital in inaugurating the consistency of models. Nevertheless, such analysis is moderately unusual in resistivity imaging data set. Electrical resistivity tomography (ERT) technique is being constantly used in many scientific areas including engineering, environmental and archaeological survey.

We believe that this contribution is theoretically and practically relevant because the proposed technology in this paper have been applied to the corresponding engineering and technology exploration. Our research has certain reference value for oil and gas exploration and natural seismic monitoring, who comprise the majority of your journal’s readers. Further, we believe that the findings match the aims and scope of your journal.

Blue Nile Basin is of vital importance for the whole Nile Basin. The investigation of the impact of climate change on this basin is a must. 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 has a negative impact on the basin in terms of temperature.

Airborne magnetic surveys are an important tool for geophysical studies. Therefore, developing a portable airborne survey system is always of high interest to the geophysical exploration community. For that reason, we are developing a portable UAV-borne magnetic system using a vertical take-off and landing UAV. To understand the platform's magnetic interference, we conducted static and dynamic experiments, which reveals that the magnetic interference is mainly from electric current in cables.

A new multi-component electricial field observation system based on autonomous underwater vehicle (AUV) was introduced for the measurement of seafloor self-potential. The system was tested in a lake and the multi-component 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.

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, whle 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 as well as an error estimate in scientific studies using magnetometer data.

We reviewed eight algorithms to estimate missing values of environmental drivers, and separately, three major fluxes in eddy covariance time series. Overall, machine learning algorithms showed superiority over the rest, and among the top three models, feedforward neural networks, eXtreme Gradient Boost, and random forest algorithms, the later showed the most solid performance in different scenarios.

Gravimetry studies the variations of the Earth’s gravity field which can be linked to mass changes studied in various disciplines of the Earth sciences. The gravitational attraction of the Earth is measured with gravimeters. Quantum gravimeters allow for continuous, high-frequency absolute gravity monitoring while remaining user-friendly and transportable. We assess the capacity of the AQG#B01, developed by Muquans, as a field gravimeter for hydro-geophysical applications.

This study investigates how useful the PIXE technique is in the analysis of complex matrix composition in earth materials. Hence it gives an information on PIXE in relation to other nuclear techniques. Results obtained by PIXE must be compared with other complementary techniques to obtain an overall elemental analysis of the matrix composition of high-grade earth materials. Finally, the results are reviewed.

At present, indoor positioning technology is used in all aspects of life. I study the positioning method of UWB radar network. Because of the interference in the indoor environment, the UWB radar measurement data produce abnormal values. In order to eliminate the outliers, the method of fitting the known true value with the actual measured value is used to obtain the linear relationship between the true value and the measured value, so as to get the unknown true value through the measured value.

This paper presents a quasi-distributed thrust measurement system based on an optical frequency domain reflectometer (OFDR). This OFDR sensing system achieved a spatial resolution of 20 cm using a 500 m test fiber (the resolution of an OTDR sensing system is generally approximately 1 m), the maximum measurement pressure can reach 1.059 MPa and the maximum relative error is 8.9 %. This system has good engineering application prospects in the safety monitoring field.

Current borehole receivers only measure a single parameter of the magnetic field component, which does not meet the special requirements of controlled source electromagnetic methods.This study proposes a borehole electromagnetic receiver which realizes multi-component synchronous acquisition of adding the vertical electric field component. Results of the experiments show that the design has the performance of low noise and wide band and that high quality CSEM signals were obtained.

This article describes the development of a mobile roadside survey procedure for obtaining corroboration data for the remote sensing of agricultural land use practices over county level areas where atmospheric conditions are unfavourable for satellite remote sensing, while improving on financial, temporal, and safety costs for in-field verification data acquisition.

This paper gives an outlook of the research aimed at development of an instrument for magnetic field survey. The developed instrument performs accurate measurements of the parameters of the Earth’s magnetic field. Such measurements are required for control of magnetic environment at observational points where the Earth’s magnetic field is continuously measured. The developed instrument is considered as a possible standard solution for assessment of artificial noise at various locations.

Nowadays ocean-bottom observatories, equipped with acceleration and pressure gauges (seismometers and tsunameters), became widespread. We suggest simple and reliable method for remote testing the calibration of the gauges installed at the ocean bottom. The method is extremely convenient for practice, since, besides measured quantities, it involves a sole physical constant – the gravity acceleration.

The CUGB-CS48DAS data acquisition system was designed for seismic purpose at first. However, we tried to integrate the acquisition circuit and after several hardware improvements and software updates, it can be used now for seismic exploration as well as electrical prospecting. It has good application effects in engineering geology, mineral geology and energy geology, and is suitable for exploration tasks in coalfields, petroleum, minerals, earthquake monitoring and urban construction, etc.

Observations of the stable isotopes of water vapor by high-resolution ground-based Fourier transform infrared spectroscopy (FTIR) provide information on study of the variation of the atmospheric water vapor at Hefei site. In this paper, the percentage of atmospheric H₂O(X_H2O) and HDO (X_HDO) have been retrieved based on a high-resolution ground-based FTIR at Hefei site, and also calculated the stable isotopes of water composition δD. The time series of X_H2O were compared with the Greenhouse gase.

Terrestrial photogrammetry is the approach by which measurements are derived from images. It is a rapidly growing method in glaciology, providing detailed records of glacier change. However, glacial photogrammetry toolboxes are limited currently. PyTrx (freely available online) has been developed here as a Python-alternative toolbox with wider capabilities for deriving velocities, areas, and line measurements. Examples are presented throughout using time-lapse imagery from glaciers in Svalbard.

Meteorological observational data obtained in highly complex terrain has to be treated differently than it is usually done within state of the art quality control procedures. The main motivation and goal is to preserve as much information as possible in order to enhance the accuracy of analysis and forecast model output. It is recommended to use the method in highly complex terrain. Sufficient data density and coherent structures within data is required.

- This study aimed to calibrate some of the existing models in the literature for estimating daily total global solar radiation parameter using available measuring records (maximum and minimum air temperatures) and three new models are developed based on maximum and minimum air temperatures and relative humidity.
- In this study, three new models that are based on the relative humidity and the difference between maximum and minimum air temperatures were suggested.

A new investigation technique for magnetic data by a 2D dipping dike has been presented. The main interpretive parameters are: the depth to the top, exact origin, and the width of dipping dike. The comparison of the results with drilling information reported in the literature demonstrated the prevalence of the suggested method and its potential for solving magnetic problem, for example in china field example the depth to the top of dike is 22.24 m and from drilling information range from 22–25.

Radar Signal processing is one of the area where there is a lot of scope for research. This area demands efficient algorithms for study of echoes derived from various atmospheric regions. Denoising techniques were used and spectral moments were calculated. Stacked doppler profile was plotted to observe the improvement in doppler detection. It has been observed that there is a considerable improvement in recognition of the doppler echoes.

An automatic process for the estimation of forest properties in high spatial resolution using National Land Survey's airborne laser scanning data is presented. Results were evaluated by compering against national MS-NFI forest data. The estimation accuracy was generally good, but deciduous forests in leaf-off conditions caused somewhat underestimation. The method can be used to support e.g. forest managing, construction planning, wood industry and other remote sensing applications and research.