The long-term drift of magnetometers at geomagnetic observatories is calibrated by a non-magnetic theodolite. We propose a numerical method to evaluate such absolute measurements in a new, more general manner. It is more flexible and helps to identify and correct or discard erroneous measurements. We derive this method and give examples showing how it improves the quality and reliability of the calibrations parameters (the so-called baseline values) of an observatory magnetometer.

To assess the performance of the developed EM receivers, this paper presents a multifunctional waveform generator with three waveforms: 1) a wideband, low-noise electromagnetic field signal to be used for magnetotelluric, audio-magnetotelluric, and long-period magnetotelluric studies; 2) a repeating frequency sweep square waveform for CSAMT and SIP studies; and 3) a “positive-zero–negative-zero” signal that contains primary and secondary fields for time-domain-induced polarization studies.

This manuscript describes a next generation airborne radar that has the potential for estimating 3-D winds and also delineating regions of ice and liquid in clouds. It takes advantage of phased array and dual-polarimetric radar technologies for retrieving winds and detecting ice and liquid regions respectively. Engineering discussion in this manuscript forms the basis for designing an optimal phased array radar system. Rapid scanning using a phased array is a critical design requirement.

The World Optical Depth Research Calibration Center (WORCC) has been established after the recommendations of WMO for calibration of aerosol optical depth (AOD) -related sun photometers. WORCC is mandated to initiate homogenization activities among different AOD networks and to run a network (GAW-PFR) of sun photometers. To calibrate such instruments aiming at low measurement uncertainties the quality assurance, quality control and a basic hierarchy have to be defined and followed.

We present a new versatile datalogger that can be used remotely for a wide range of applications in geosciences such as environmental and groundwater monitoring or in applied geophysics. The recorded signals will be processed using a new software approach, which will improve the data quality for very poor signal-to-noise ratios. We show this improvement by comparing it with traditional software-algorithm-processing synthetic data sets and real data collected in the field.

CÆLIS is a software system which aims at simplifying the management of a photometric ground-based network, providing tools by monitoring the instruments, processing the data in real time and offering the scientific community a new tool to work with the data. The present work describes the system architecture of CÆLIS and some examples of applications and data processing.

Cosmic-ray neutron sensing (CRNS) is a unique technology to monitor water storages in complex environments, non-invasively, continuously, autonomuously, and representatively in large areas. However, neutron detector signals are not comparable per se: there is statistical noise, technical differences, and locational effects. We found out what it takes to make CRNS consistent in time and space to ensure reliable data quality. We further propose a method to correct for sealed areas in the footrint.

This is a theoretical seismology paper which implements known algorithms for surface wave propagation across single, vertical discontinuities in 2-D media. Seismic surface waves undergo mode conversion at lateral discontinuities and this paper describes a Python software package for accurate computation of these conversion effects, a novel feature not available in the existing seismological literature. This work was done during my PhD research in order to validate a finite-difference wave solver.

Based on the morphological characteristics of the four dayside auroral types on images at the Chinese Arctic Yellow River Station (YRS), and by extracting the local binary pattern features and using k-nearest classifier, we make an automatic classification to the auroral images of the YRS and the South Pole Station and obtain the occurrence distribution of the dayside aurora morphology. The results indicate that these auroral types present similar occurrence distributions in the two stations.

The paper presents the first results of ground penetrating radar investigation in the church in Kłodzko, Poland. The research was part of SEG Field Camp, which was organized by SEG Student Chapter Cracow and SEG Bucharest Student Chapter. The aim was to verify the presence of possible underground structures. Among the most important discoveries are previously unknown crypts. Results of the research might be helpful for future archeological excavations and other investigations in the church.

The presence of magnetic fields in space dominate the way planets interact with different types of plasmas. Thus, measuring them is extremely important when studying space. We present an instrument capable of measuring magnetic fields at a fraction of the cost, power and size of traditional magnetometers. With this technology, a science-grade magnetometer for small satellites can be achieved, enabling the study of the space environment with large clusters of sensors in future missions.

The authors have successfully recommissioned an unused tri-axial Helmholtz coil system. The system now serves as a national facility for calibrating magnetometers.

To provide reliable time series of evapotranspiration, we evaluated the performances of four different gap-filling methods when tailored to conditions of hilly crop fields. The tailoring consisted of splitting the time series beforehand on the basis of upslope and downslope winds. The obtained accuracies on evapotranspiration after gap filling were comparable to those previously reported over flat and mountainous terrains, and they were better with the most widely used gap-filling method.

This study presents a new instrument called a low-cost albedometer (LCA) composed of two illuminance sensors. The ratio between reflected vs. incident illuminances is called the albedo index and can be compared with actual albedo values. We demonstrate that our system performs well and thus provides relevant opportunities to document spatiotemporal changes in the surface albedo from direct observations at the scale of an entire catchment at a low cost.

CWT was applied for lithology detection over the Costa Rica margin, using gamma ray logs as a best indicator. It is observed that four major sedimentary layers terminated there with a gabbroic sill. DWT was applied on density logs to identify small changes in the rock matrix. Accordingly, wavelet-based fractal analysis was applied on every sedimentary layer. This analysis indicates that a certain portion of wells contain abundant shale and low-energy environments.

A fast Fourier transform was applied to fit the geomagnetic diurnal variation. Fitting results showed that when the polynomial degree was greater than 160, the residual error was close to 0 nT. White noise is the main component of the residual error when the polynomial degree was greater than 160, so this method was adopted to calculate the background noise of the geomagnetic field. Spectrum analysis further demonstrated the necessity to remove background noise from geomagnetic data.

To improve microwave satellite and airborne observation products in forest environments, a precise and reliable estimation of the permittivity of trees is required. We developed a probe suitable to measure the permittivity of tree trunks at L band in the field. The system is easily transportable in the field, low energy consuming, operational at low temperatures and weatherproof. The permittivity of seven tree species in both frozen and thawed states was measured, showing important contrast.

The main purpose of this paper is to introduce a receiver system for the synchronous acquisition of multiple electromagnetic signals in transient electromagnetic prospecting to achieve multiparameter and multichannel synchronous reception. The reliability, practicability, and data validity of the receiver were verified by different kinds of testing. It can be used for the reception of pseudorandom signals and distributed 3-D data, which can improve geophysical exploration efficiency.

A DTS system, using fibre-optic cables as a temperature sensor, measured surface and subsurface temperatures at a boreal forest underlain by permafrost in the interior of Alaska for 2 years every 30 min at 0.5-metre intervals along 2.7 km to monitor the daily and seasonal temperature changes, whose temperature ranges between −40 ºC in winter and 30 ºC in summer. This instrumentation illustrated characteristics of temperature variations and snow pack dynamics under different land cover types.

This BPNN approach with two alarms was well suited, and it was not necessary to consider the problems of characterising the wave phases and pre-processing, as stated previously. Furthermore, BPNN is a mature technology, which is expected to develop rapidly in the future, and does not require complex hardware. Determining an initial location and magnitude of the event was not necessary for this technique. An existing seismic monitoring network can be used.

TanSat is a key satellite mission in the Chinese Earth Observation program and is designed to measure the global atmospheric column-averaged dry-air CO₂ mole fraction. Several critical aspects of the spectrometer, including the spectral resolution, spectral dispersion, and the instrument line shape function of each channel were evaluated. The instrument line shape function of the spectrometer is notably symmetrical and perfectly consistent across all channels in the three bands.

In this study, a high-precision distributed wireless microseismic acquisition system has been designed for oil and gas exploration. The system design, which was based on the ADS1274 chip manufactured by TI, made full use of the four channels of the chip to collect vibration signals in three directions and one electrical signal, respectively. Furthermore, the acquisition system used GPS and WIFI technologies to achieve distributed wireless acquisition.

We present a proof-of-concept space-flight instrument that can simultaneously make measurements of both the low- and high-frequency local magnetic field. Previously, this would have required two separate instruments that would normally have had to be mounted separately on long deployable booms to keep them from interfering. This new hybrid instrument is expected to be particularly useful on extremely small spacecraft, such as CubeSats, which can only accommodate a few instruments.

Historical surveys performed through the use of aerial photography gave us the first maps of the Arctic. Nearly a century later, a renewed interest in studying the Arctic is rising from the need to understand and quantify climate change. It is therefore time to dig up the archives and extract the maximum of information from the images using the most modern methods. In this study, we show that the aerial survey of Svalbard in 1936–38 provides us with valuable data on the archipelago's glaciers.

Climate change studies are growing and related experiments are getting bigger and more complex. They are often conducted in remote areas where communications are limited. In cases like that the data can be transferred via a satellite connection, but these types of connections are slow. We found that by using the little known possibilities of LoggerNet software (the most popular data logger software in environmental science) it is possible to transfer quite a large amount of data.

The current article focuses on plant diversity assessment in arid environments. Species richness and species evenness equations were used to meet the objectives. Remote sensing techniques were used to detect normalized difference vegetation index (NDVI) temporal changes. Two datasets were used to realize the NDVI, and post-chance detection (PCC) techniques were used to evaluate plant diversity status over a period of 4 years. The results show a recognizable loss in plant biodiversity.

We measure spectra of upper atmospheric emissions in optical wavelengths using the High Throughput Imaging Echelle Spectrograph (HiTIES) located on Svalbard. These spectra contain superposed emissions originating from different altitudes. In this paper, we describe a fitting method which allows us to separate the measured emissions, thus allowing us to measure neutral temperatures at different altitudes and the density of water vapour in the atmosphere above the instrument.

We are planning a Mars mission. The mission will carry an instrument capable of measuring and mapping molecular oxygen and water in the Martian atmosphere, as well as the temperature, wind, and magnetic field. Water and oxygen are vital parts of the Martian atmospheric chemistry and must be better understood. Using computer simulation results, the paper gives a description of how the measurements will work, some problems we expect to encounter, and the sensitivity of the measurements.