Preprints  

Overall accuracy of CO₂/H₂O data from open-path eddy-covariance systems is modeled for data analysis. The model is further formulated into CO₂ and H₂O accuracy equations for uses. Based on atmospheric physics and bioenvironment, both equations are used to evaluate accuracy of ecosystem CO₂/H₂O data and, as rationales, to assess field CO₂/H₂O zero and span procedures for the systems. The procedures are assessed for measurement improvement. An impractical H₂O span while cold is found unnecessary.

Construction, operation and analysis of an sEIT field-monitoring setup with high spatial and temporal resolution is presented. Electromagnetic induction errors are corrected, allowing the recovery of images of in-phase conductivity and electrical polarization of up to 1 kHz.

This review paper attempts to discuss how, the disruption of AI based data processing, has changed significantly the way Geomatics data are processed and interpreted. Among the sub-disciplines that are included in the umbrella of Geomatics, we focused on the kind of data that have been more recently faced by the research community, and tried to outline the recent trends and future research directions.

In airborne survey, the dynamic flight conditions cause the unequal data levels which have serious impact on airborne geophysical data analysis and interpretation. A new technique is proposed to level geophysical data in view of the image space properties. We have confirmed the reliability of the method by applying it to the AEM, magnetic data, and apparent conductivity data. The method can automatically extract the leveling errors without the participation of staff members or tie-line control.

In recent years, imaging of density inside volcanoes using cosmic-ray muons, has been studied. In some previous studies, observations were conducted in 2 or 3 directions to obtain 3D resolution. For higher resolution, we tried to observe a volcano from 11 directions using special photographic films. The observation and analytical techniques developed in this study may be applied to other volcanoes and large objects. Reconstructing 3D images of the volcano is in progress using the obtained data.

Surface Energy Balance (SEB) closure check and important environmental variables monitoring require soil heat flux measurement. On one hand every experimental technique has its possible errors and need to be checked and corrected. On the other hand, SEB equation should include all sensed energy sources and sinks.

Most measurements of air temperature and humidity originate from Stevenson-type thermometer screens, which can produce erroneous measurements in light winds owing to insufficient ventilation of the in-screen sensors. A field experiment to measure airflow within a Stevenson screen found mean airflow to be only 0.2 m s⁻¹, well below the 1 m s⁻¹ minimum normally assumed, and only 7 % of 10 m mean wind speeds. Implications for air temperature and humidity measurement uncertainties are discussed.

Sensors capable of measuring rapid fluctuations are important to improve our understanding of environmental processes. Many sensors are unable to do this, due to their reliance on the transfer of the measured property, for instance a gas, across a semi-permeable barrier. We have developed a mathematical tool which enables the retrieval of fast response signals from sensors with this type of sensor design.

We present an experiment intended to enable extremely low-noise magnetic field measurements. We manufactured fluxgate magnetometer cores using two metal alloys, two geometries, two foil thicknesses, and six different heat treatments and compared the resulting material properties, power consumption, and magnetic noise. Our results suggest that thinner foils, potentially using a new copper alloy, manufactured into continuous racetrack washers may provide excellent performance in fluxgate sensors.

Using an underwater buoyancy powered autonomous glider, we collected profiles of temperature and salinity from the ocean NE of Barbados. Most of the temperature and salinity profiles contained staircase like structures of alternating constant values and large gradients. We wrote an algorithm to identify these staircases. We hypothesise that these staircases are prevented from forming where background gradients in temperature and salinity are too great.

Weather balloons are released every day around the world, to obtain up to date atmospheric data for weather forecasting. Expanding the range of sensors they carry can make measurements of additional quantities available, such as for atmospheric turbulence, cloud electricity, energetic particles from space and, in emergency situations, volcanic ash or radioactivity. An adaptable system has been developed to provide these and other measurements, without interfering with the core weather data.

When radio waves from our Galaxy enter the Earth's atmosphere, they are absorbed by electrons in the upper atmosphere. It was thought that by measuring the amount of absorption, it would allow the height of these electrons in the atmosphere to be determined. If so, this would have significance for future instrument design. However, this paper demonstrates that it is not possible to do this, but it does explain how multiple-frequency measurements can nevertheless be useful.

Better monitoring of sequestered soil carbon in different soils and climate conditions due to carbon farming practices is needed. For this, we, Field Observatory Network (FiON), have established a methodology towards monitoring and forecasting agricultural carbon sequestration by combining offline and near real-time field measurements, weather data, satellite imagery and modeling. To disseminate our work, we have built a web-based dashboard called Field Observatory (fieldobservatory.org).

DMA-based algorithm developed by the authors allows us to solve the main tasks of cyclostratigraphy: periodograms were constructed with further identification of repetitive cycles for carrying out geological reconstructions and correlations of sediments of the same age over a large area.

The importance of the soil evaporation concerns our main life supports source. A simple to operate instrument made for soil evaporation measurement appears then suitable. Any measurement technique may perturb the monitored space affecting external conditions such as the air temperature or the wind. In order to perform a reliable measurement all these perturbations need to be estimated and corrected. A device and a protocol allowing soil evaporation corrected measurement is described

The quality control and validation activities performed by the Swarm Data Quality Team reveal the good quality LP. The analysis demonstrated that the current baseline plasma data products are improved with respect to previous baseline. The LP have captured the ionospheric plasma variability over more than half of a solar cycle, revealing the data quality depenndence on the solar activity. The quality of the LP data will further improve promoting their application to a broad range of studies.

Cosmic Ray Neutron Sensing (CRNS) is a non-invasive tool for measuring hydrogen pools like soil moisture, snow, or vegetation. This study presents a directional shielding approach, aiming to measure in specific directions only. The results show that non-directional neutron transport blurs the signal of the targeted direction. For typical instruments, this does not allow acceptable precision at a daily time resolution. However, the mere statistical distinction of two rates is feasible.

We use the technical methods of instrument development, calibration experiments and numerical simulation to develop a new type of in-situ stress sensor group using fiber Bragg grating (FBG) sensing technology, which can calculate the in-situ stress state of surrounding rock mass by sensing the borehole wall strain. This sensor group lays an important theoretical and experimental foundation for the development and application of FBG hole-wall strain gauge.

Based on an analysis of the differences between DEM and point cloud data, including the corresponding acquisition methods, data structures and model construction methods, this paper proposes a 3D point set data model based on regular grid 2D data field for regional modeling. The feasibility of the model is tested through the upper and lower boundary modeling method.

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 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.

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.

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.

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.

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.