Preprints  

This study aims to figure out the ideal cryptographic technique for End-To-End Encryption security for educational purposes. For this purpose, various encryption methodologies are compared to various metrics including encryption time, decryption time, retrieval time and number of data size versus Encryption for the NPTEL cloud database and an enhanced role-based technique has been suggested.

Motivated by recent community interest in a satellite mission to the atmospheric LTI region between 100 km and 200 km altitude, the DIPCont project is concerned with vertical profiles of key LTI variables and their reconstruction from dual-spacecraft and single-spacecraft observations. Considering a novel non-isothermal scenario, the report presents a set of self-consistent parametric models, introduces the probabilistic DIPCont modeling framework, and discusses first results.

This project aims to demonstrate the viability of the development of a concept prototype that has, as a differential, free software and hardware used in its development and operation, and thus, has unique characteristics compared with commercially available equipment for signal detection was employed, providing strong rejection of spurious electrical noise, typical of urban areas. This project and important academic contribution to open-source instrumental research.

Important topics in Land-Atmosphere feedback research are water and energy balances and heterogeneities of fluxes at the land-surface and in the atmosphere. To target these questions, the Land-Atmosphere Feedback Observatory (LAFO) has been installed in Germany. The instrumentation allows comprehensive measurements from the bedrock to the troposphere. The LAFO observation strategy aims for simultaneous measurements in all three compartments: atmosphere, soil and land-surface and vegetation.

Accurate monitoring of water in soil can improve irrigation efficiency, which is important considering climate change and the growing world population. Cosmic-ray neutrons sensors (CRNS) are a promising tool in irrigation monitoring due to a larger sensed area and to lower maintenance than other point-scale sensors. Here, we analyse the feasibility of irrigation monitoring with CRNS and the impact of the irrigated field dimensions, of the variations of water in soil, and of instrument design.

The manuscript describes the ground-based camera equipment to obtain images from the dust ablation phenomena (meteors) in the Earth atmosphere. The meteors are observed from two locations , but one station is equipped with a camera containing a spectral grating which allows to follow and determine the spectral information through the meteor ablation process. We describe the data merging, calibration, and processing to finally derive to the meteor composition.

Magnetic field measurements in space can be contaminated by stray magnetic fields from their host satellite. We present an automated tool for measuring the magnetic field generated by potential satellite and instrument components to identify those that may degrade the measurements taken on-orbit. This tool is designed for use by the Tandem Reconnection and Cusp Electrodynamics Reconnaissance Satellites (TRACERS) Small Explorers mission and is currently being used for mission design activities.

This paper outlines the development of a color filter wheel, attached to a broadband CL detector, which allows us to recover spectroscopic information and generate composite color images. The embedded data from the pixels were used to generate 2D and 3D graphs providing multiple visual pathways for comparing relative intensities. The design can be adjusted to accommodate various chamber specifications and expand the capabilities of the broadband CL detectors housed at many institutions.

In most cases, the Soil Water Content measurement is carried out using commercially available dielectric permittivity-based probes such as Time Domain Reflectometers or Frequency Domains Reflectometers. However, these probes use transfer functions which may be inadequate in the concerned soil. Raw SWC measurement in clayey soil shows an important relative error. A simple protocol is presented which allows for recovery of an acceptable accuracy of the FDR SWC measurements.

Potential users of all sky camera images include even power company, tourists and aurora enthusiast. However, these potential users are normally not familiar to interpreting these images. To make them comprehensive for wide users, we developed an automatic evaluation system of the auroral activity level. The method involves two steps: first making a simple set of numbers that describes the auroral activity, and then further simplifying them into several levels (Level 6 is aurora explosion).

The design, characteristics, and performance of a CubeSat magnetometer board (Quad-Mag) equipped with four PNI RM3100 magnetometers is presented. The inclusion of four sensors allows a potential factor of two reduction in the noise floor established for an individual sensor via oversampling with multiple sensors. The Quad-Mag is shown to enable 1 nT magnetic field measurements at 1 Hz and 5.345 nT at 65 Hz using commercial-off-the-shelf sensors for space applications.

The Sweeping Langmuir Probe on board the PICASSO CubeSat was designed to measure the plasma parameters. Before launch, the instrument has been tested in a plasma chamber. It is shown that the traditional method to interpret the data cannot be applied directly for this type of probes, and an adaptation is proposed. It is reported how, with a reduced number of data points, the plasma parameters can still be retrieved. Finally, the effect of the contamination of the probe surface are investigated.

Electromagnetic sensors in a drone setup allow a lot of movability and downscale the cost and risk typically associated with an airborne system. This paper discusses the pros and cons of our newly developed drone-towed sensor system, where we use the controlled source electromagnetic sensor GEM2-UAV. We conduct 6 different tests dealing with altitude dependency, temperature drift, transmission frequencies, T- and P-mode, and drone noise. Additional, we show a data set collected with the system.

MDAL is a near real-time, satellite-based surface albedo product based on the geostationary Meteosat Second Generation mission. We propose an update to the processing algorithm that generates MDAL and evaluate the results of these changes through comparison against the pre-update, currently operational MDAL product, as well as another satellite based albedo product, ETAL, and data based on in-situ measurements. We find that the update provides a valuable improvement.

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.

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.

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.

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.