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The classical radio-magnetotelluric (RMT) method is nowadays routinely applied to various environmental, engineering, and exploration problems. The technique uses radio transmitters broadcasting in the frequency range of 10 kHz to 1 MHz, and the measurements are carried out in the far field. The well-known disadvantages of RMT are a lack of robust radio transmitters in remote areas; the absence of transmitters broadcasting below 10 kHz, which limits the penetration depth; and a possible low signal-to-noise ratio. To overcome these difficulties, controlled sources can be used (controlled-source RMT [CSRMT]). We extend the CSRMT method to perform measurements not only in the far field but also in the transition zone. In CSRMT practice, it often is challenging to maintain far-field conditions for logistical reasons. Therefore, part of the measured data contains signatures of the source field, which cannot be interpreted with magnetotelluric software. In addition, the source placed directly in the survey area allows us to increase the signal-to-noise ratio and resolution. Such CSRMT in the transition zone is, in fact, a controlled-source electromagnetic method but with full impedance tensor and tipper vector transfer functions. We develop new procedures for the 3D modeling and inversion of the tensor radio-frequency data measured in the transition zone of two perpendicular horizontal electric dipole sources. In this case, the geometry of the source must be considered in the forward modeling. The developed modeling and inversion software is tested on a synthetic 3D model. The 3D resistivity models derived from the real data confirm the geologic settings and are consistent with the available borehole information. Therefore, we conclude that the CSRMT approach extended to include the source field is feasible and that the developed procedures are reliable.

The article is devoted to an overview of the latest trends in the study of the written heritage of the merchants of Russia. The author examines the principles and approaches to the study and publication of merchant autobiographical and epistolary texts set forth in the works of the last two decades. Special emphasis in the article is made on the study and publication of the written heritage of merchants from different regions in the context of the complex ethno-cultural structure of Russian society in the modern era. The main trends in the study of memoirs and epistolary complexes of the Russian merchants of the 17th - early 20th century are highlighted, and their main publications are characterized. The observations and remarks make it possible not only to characterize the current state of the study of the written heritage, cultural level, mentality and self-consciousness of the merchant class, but also to outline the prospects for such research area. The author comes to the conclusion that it is necessary to conduct complex interdisciplinary research, including historians, literary scholars, linguists, and carried out through the use of modern technical methods of working with handwritten texts.

SUMMARY Various electromagnetic (EM) techniques have been developed for exploring natural resources. The novel frequency-domain semi-airborne controlled source electromagnetic (semi-AEM) method takes advantages of both ground and airborne techniques. It combines ground-based high-power electrical dipole sources with large-scale and spatially densely covered magnetic fields measured via airborne receivers. The method can survey the subsurface down to approximately 1000 m and is particularly sensitive towards conductive bodies (e.g. mineralized bodies) in a more resistive host environment. However, the signal-to-noise ratio of semi-AEM is lower than that of ground-based methods such as long-offset transient electromagnetics (LOTEM), mainly due to the limited stacking time and motion-induced noise. As a result, the semi-AEM often has reduced depth of investigation in comparison to LOTEM. One solution to overcome these flaws is to analyse and interpret semi-AEM data together with information from other EM methods using a joint inversion. Since our study shows that LOTEM and semi-AEM data have complementary subsurface resolution capabilities, we present a 2-D joint inversion algorithm to simultaneously interpret frequency-domain semi-AEM data and transient electric fields using extended dipole sources. The algorithm has been applied to the field data acquired in a former mining area in eastern Thuringia, Germany. The 2-D joint inversion combines the complementary information and provides a meaningful 2-D resistivity model. Nevertheless, obvious discrepancies appear between the individual and joint inversion results. Consequent synthetic modelling studies illustrate that the discrepancies occur because of (i) differences in lateral and depth resolution between the semi-AEM and LOTEM data caused by different measuring configurations, (ii) different measured EM components and (iii) differences in the error weighting of the individual data sets. Additionally, our synthetic study suggests that more flexible land-based configurations with sparse receiver locations are possible in combination with semi-AEM without a significant loss of target resolution, which is promising for accelerating data acquisition and for survey planning and logistics, particularly when measuring in inaccessible areas.

This article presents the current results of an ongoing study of the possibilities of fine-tuning automatic morphosyntactic and semantic annotation by means of improving the underlying formal grammar and ontology on the example of one Tibetan text. The ultimate purpose of work at this stage was to improve linguistic software developed for natural-language processing and understanding in order to achieve complete annotation of a specific text and such state of the formal model, in which all linguistic phenomena observed in the text would be explained. This purpose includes the following tasks: analysis of error cases in annotation of the text from the corpus; eliminating these errors in automatic annotation; development of formal grammar and updating of dictionaries. Along with the morpho-syntactic analysis, the current approach involves simultaneous semantic analysis as well. The article describes semantic annotation of the corpus, required by grammar revision and development, which was made with the use of computer ontology. The work is carried out with one of the corpus texts – a grammatical poetic treatise Sum-cu-pa (VII c.).

The article focuses on the historiography of Russian memoir literature of the 17th– 18th centuries. The authors turned to general studies in humanities (literary, historical, cultural, and philosophical) which discuss theoretical problems of classification and internal systematization of the varieties of memoir literature. The evolution of the terminological apparatus used within memoir studies is shown separately. A special aspect, reflected in the article, concerns attention of the researchers to the manuscript culture and the existence of monuments of memoir literature within this culture. Considering the history of the question chronologically, the authors of the article identify several periods, describe major research schools within the framework of traditional research, and discuss the studies in the field of the “new” methodological paradigm. Addressing the problem of classification in historiography demonstrates the need for further study of key problems in the memoir studies. In conclusion, the authors identify perspective direction towards creating adequate principles of classification, defining genre delimitations and criteria for selecting memoir monuments that exist in the manuscript tradition.

The shape of gaseous planets, defined as an equipotential surface for a specific pressure, can be calculated given measurements of the zonal gravity harmonics, and the wind profile and polar radius at a given level. For both Jupiter and Saturn, the gravity harmonics have been measured to high accuracy by the Juno and Cassini missions, respectively. Measurements for the zonal winds are also available via cloud tracking, buth a significant uncertainty is associated with them, stemming from the clouds altitudes, as well as time variations in the strength and location of the winds. With that, the wind profiles can be also constrained by the gravity measurements. Further constraint on the calculated shape of the two gas giants can be obtained from occultation measurements, which give radial dependent profiles of pressure for specific spatial location.Here we propose a new method for calculating the shape of the gas giants, based on an optimization of the wind latitudinal profile, decay structure, and the polar radius, given both gravity and occultation measurements. We use thermal wind balance to relate the wind to the gravity measurements, and a shape model to relate the wind and polar radius to the occultation measurements. We perform the analysis for both the 0.1 and 1 bar pressure levels. We examine the ability to explain both types of measurements in each planet, and discuss the implication for the possible wind profiles and how they might change with pressure. We also discuss the solutions for the polar radius with respect to the currently used mean values.Only a few occultation measurements are currently available in each planet, but in the coming years the Juno mission is expected to perform dozens of occultations for Jupiter, covering a wide spatial range, and there are several Cassini occultations performed for Saturn that are still waiting for analysis. Using the method proposed here, we expect the new measurements to help resolve the shape of the gas giants to better accuracy, and to allow better understanding of the wind structures and their depth dependence.

The shallow layers of the Jovian atmosphere, the only regions accessible to direct investigation through in situ sampling and remote sensing experiments, are the looking glass through which the unknowns of the dynamical structure are revealed. Radio occultation measurements have proved to be a key factor in the study of planetary atmospheres’ thermal structure, dynamics and composition.During both the extended Juno mission and the upcoming JUICE mission to Jupiter, an unprecedented number of radio occultations are planned to be performed, reaching to a depth of up to 2 bar, with much broader spatial coverage than previously performed. These experiments could be used to better understand the physical properties and dynamics of Jupiter’s atmosphere, not only at the upper cloud level region (~1 bar) but also much deeper (down to 1000s bars), by using these measurements as constraints to general circulation models (GCMs) that simulate the flow on the gaseous planet. Here, we develop a 3D general circulation model for the dynamical region of Jupiter, driven by a Newtonian cooling scheme with temperature fields derived either from the observed winds (thermal wind balance) or by using in-situ temperature measurements from the Cassini mission’s CIRS or TEXES instruments. The model is used to reproduce the dynamics of Jupiter at the upper levels (mainly the zonal jets) while allowing the dynamics to evolve freely below the cloud level. When the radio occultation experiments will be available for analysis, they could replace or be added to the above thermal profiles used to force the GCM. Combining radio occultations with dynamical modeling of the Jovian atmosphere, will lead to a twofold improvement of the understanding of the structure of the atmosphere at the cloud level and the deep atmospheric dynamics.

There is a clear demand to increase detection depths in the context of raw material exploration programs. Semi-airborne electromagnetic (semi-AEM) methods can address these demands by combining the advantages of powerful transmitters deployed on the ground with efficient helicopter-borne mapping of the magnetic field response in the air. The penetration depth can exceed those of classic airborne EM systems because low frequencies and large transmitter-receiver offsets can be realized in practice. A novel system has been developed that combines high-moment horizontal electric bipole transmitters on the ground with low-noise three-axis induction coil magnetometers, a three-axis fluxgate magnetometer, and a laser gyro inertial measurement unit integrated within a helicopter-towed airborne platform. The attitude data are used to correct the time series for motional noise and subsequently to rotate into an earth-fixed reference frame. In a second processing step, and as opposed to existing semi-AEM systems, we transform the data into the frequency domain and estimate the complex-valued transfer functions between the received magnetic field components and the synchronously recorded injection current by regression analysis. This approach is similar to the procedure used in controlled-source EM. For typical source bipole moments of 20–40 kAm and for rectangular current waveforms with a fundamental frequency of approximately 10 Hz, we can estimate reliable three-component (3C) transfer functions in the frequency range from 10 to 5000 Hz over a measurement area of [Formula: see text] for a single source installation. The system has the potential to be used for focused exploration of deep targets.

PurposeThis study aims to systematize and critically analyse existing indices and frameworks on digital capabilities with the focus on consumers’ digital capabilities, identify opportunities for their further development and suggest agenda for future research.Design/methodology/approachA sample of 18 frameworks and indices of consumers’ digital capabilities were compared based on their purposes, stakeholders, scope and application areas.FindingsThe study concludes with propositions that generalise current views on conceptualisation, measurement and management of consumers’ digital capabilities. Each proposition is further investigated in terms of possible implications for research and practice.Practical implicationsThe study indicates opportunities for businesses not only to consider consumers as recipients and adopters of digital technologies but also to aim to understand how to proactively involve consumers in value co-creation, help them be better educated and have a comprehensive understanding of potential outcomes of their participation in the digital economy.Social implicationsHighlighting individual consumer perspective in existing indices and frameworks will help consider the interests of society and provide win-win opportunities for everyone involved in the digital marketplace through bottom-up engagement in addition to top-down regulation and monitoring.Originality/valueThis study contributes to the extant literature threefold: firstly, existing digital capability frameworks and indices are systematized and critically investigated using criteria of stakeholders, purpose and aims; secondly, consumers are identified as principal stakeholder group whose interests are insufficiently presented in existing indices; thirdly, an integrative approach is suggested for a crucial comparison of existing indices, frameworks and their methodology with the focus on consumers’ interests.

The current study provides empirical insight into the nature of creating relational rents when managing business relationships in the context of the emerging Russian economy. Addressing both formal and social business network relationships, the study aims to understand the role of a systematic and purposeful approach to building and managing business relationships in order to generate superior relational advantage. The study explores the effects on both subjectively and objectively measured relational rents. Additionally, the role of institutional context in both shaping relationships and obtaining relational rents is considered through the inclusion of dysfunctional competition and institutional support. The results of a survey on a sample of 148 business-to-business firms demonstrate the leading role of the business relationship portfolio in generating relational rents, as well as the supporting role of relational capabilities in building this relationship portfolio. These effects are significantly affected by institutional moderators, demonstrating multidirectional effects on the mechanisms behind building relationships and obtaining the associated relational advantage.

Permian-Triassic rifts of the West Siberian basin compose one of the largest continental rift systems in the world. The Koltogor-Urengoy and Khudosey rifts of meridional strike are the main structures in the eastern part of the basin and are filled mainly by basaltic lavas with clastic sediments. However, in the central part of the West Siberian plate felsic lavas are widespread along with mafic volcanics. Here we present the detailed data on composition of lavas, whole-rock geochemistry, geophysical features and U-Pb ages from the Frolov-Krasnoleninsky region in the central part of the West Siberian basin.Within the studied region, Permian-Triassic rifts of NW and NE strike are predominant. The main structure is Rogozhnikov-Nazym graben of NW strike, composed of rhyolite-dacitic lavas. According to the seismic data, this volcanic area comprises multiple local eruptive centers (1-5 km in diameter). Lavas constitute the major part of the volcanic pile, while tuffs are subordinate (up to 15%). Deep boreholes did not reach the base of volcanic sequence, but its thickness exceed 0.5 km.The main geochemical features of the Rogozhnikov-Nazym volcanics are: 1) acidic composition and increased alkali content; 2) signs of supra-subduction setting: Ta-Nb and Pb anomalies; 3) high ratios of all incompatible trace elements. According to these features, volcanic rocks of the Rogozhnikov-Nazym graben were formed in the setting of post-collisional extension. Furthermore, coeval felsic lavas are widespread in smaller structures of the Frolov-Krasnoleninskiy region and demonstrate similar geochemical characteristics.We obtained 9 U-Pb (SHRIMP) ages from felsic lavas of the Rogozhnikov-Nazym graben and other rift structures. All samples yielded ages in the range from 254±2 to 248.2±1.3 Ma (Late Permian – Early Triassic). Thus, volcanic activity in the Frolov-Krasnoleninsky region was nearly synchronous to the main phase of Siberian Traps magmatism in the Siberian platform.Volcanic rocks of the Frolov-Krasnoleninsky region constitute rifts of NW strike (mainly felsic lavas, including the Rogozhnikov-Nazym graben) and NE strike (mainly mafic lavas, geochemically similar to the Siberian Traps basalts). We suggest that orientation of rifts inherits two conjugate strike-slip fault systems, which mark the W-E compression during the preceding collisional event in the Early-Middle Permian, and the mechanism of extension is similar to pull-apart model. The contrasting composition of volcanics can be caused by different-depth zones of magma generation.The Permian-Triassic volcanics are overlain by continental coal-bearing coarse-grained volcanoclastic sediments of the Chelyabinsk Group (Middle Triassic – Early Jurassic). These deposits fill the local depressions in the paleotopography. The Middle Jurassic clastic Tyumen Formation overlays both volcanic rocks and Chelyabinsk Group, covers almost the entire territory of the Frolov-Krasnoleninsky region and marks the initiation of post-rift subsidence in the West Siberian basin.

The basement of West Siberian plate has mosaic architecture and consists of the Paleozoic fold belts and supposed Precambrian massifs. The Frolov-Krasnoleninsky region is located in the central part of the West Siberian basin (near the town of Khanty-Mansiysk) and occupies the key position in its structure. The junction of the Uralian fold belt, Kazakhstan superterrane, and Irtysh-Zaysan fold zone is located there. However, the pre-Jurassic tectonic evolution of this area is still poorly constrained. Based on the new representative data on drill cores from deep boreholes and geophysical data, whole-rock geochemistry and U-Pb ages, we reconstructed the main stages of the geological history of this area:In the Neoprotertozoic the ancient metamorphic complexes of the Krasnoleninsky and Aprel’sky uplifts were formed. Based on the detrital zircons ages and correlation with similar rocks in the nearby fold belts, we suggest that this stage terminated about 600-540 Ma. In the Early Paleozoic volcano-terrigenous rocks were accumulated mainly in the island arc tectonic setting. This stage ended with the emplacement of gabbro-granitic plutons, fold deformations and amalgamation of the Kazakhatan superterrane with the Krasnoleninsky block in the beginning of Silurian (446-440 Ma). In the Devonian – Early Carboniferous carbonate and overlying mainly clastic sediments were accumulated. The first manifestation of supra-subduction volcanic activity and granitic intrusions are identified as Late Devonian-Early Carboniferous. At the end of Early – beginning of Middle Carboniferous fold deformations related to the closing of back-arc basin took place. In the Middle – Late Carboniferous differentiated volcanic series and coeval granodiorite massifs of the continental arc tectonic setting were formed (310-307 Ma). This stage corresponds to the convergence of continental masses of Siberian and East European platforms and Kazakhstan superterrane and the closing of relic oceanic basins between them. The Early-Middle Permian is a time of collision, manifested by large granitic plutons in the Krasnoleninsky uplift and other areas of the West Siberia and Uralian fold belt (290-260 Ma). At this stage, main structural features of the basement of West Siberian plate were formed. In the Late Permian – Early Triassic West Siberia was an area of wide-scale rifting, caused by the post-collisional extension and the mantle plume ascent. Thick sequences of the contrasting basaltic and felsic lavas were erupted. Volcanic piles are overlain by clastic coal-bearing sediments of the Triassic and, possibly, Early Jurassic age.

Daniel P Nemeth,1– 3 Xiaoyu Liu,3 Daniel B McKim,4 Damon J DiSabato,2,5 Braedan Oliver,2 Anu Herd,3 Asish Katta,1 Christina E Negray,1,2 James Floyd,3 Samantha McGovern,3 Paige S Pruden,2 Feiyang Zhutang,2 Maria Smirnova,3 Jonathan P Godbout,2,5 John Sheridan,1,2 Ning Quan3 1College of Dentistry, The Ohio State University, Columbus, OH, USA; 2Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; 3Stiles-Nicholson Brain Institute, Florida Atlantic University, Jupiter, FL, USA; 4Department of Animal Sciences, University of Illinois Urbana-Champaign, Champaign, IL, USA; 5Department of Neuroscience, The Ohio State University, Columbus, OH, USACorrespondence: Daniel P Nemeth; Ning Quan, 5353 Parkside Drive, Jupiter, FL, 33458, USA, Email nemethd@fau.edu; nquan@health.fau.eduIntroduction: Lipopolysaccharide (LPS) preconditioning involves repeated, systemic, and sub-threshold doses of LPS, which induces a neuroprotective state within the CNS, thus preventing neuronal death and functional losses. Recently, proinflammatory cytokine, Interleukin-1 (IL-1), and its primary signaling partner, interleukin-1 receptor type 1 (IL-1R1), have been associated with neuroprotection in the CNS. However, it is still unknown how IL-1/IL-1R1 signaling impacts the processes associated with neuroprotection.Methods: Using our IL-1R1 restore genetic mouse model, mouse lines were generated to restrict IL-1R1 expression either to endothelia (Tie2-Cre-Il1r1r/r) or microglia (Cx3Cr1-Cre-Il1r1r/r), in addition to either global ablation (Il1r1r/r) or global restoration of IL-1R1 (Il1r1GR/GR). The LPS preconditioning paradigm consisted of four daily i.p. injections of LPS at 1 mg/kg (4d LPS). 24 hrs following the final i.p. LPS injection, tissue was collected for qPCR analysis, immunohistochemistry, or FAC sorting.Results: Following 4d LPS, we found multiple phenotypes that are dependent on IL-1R1 signaling such as microglia morphology alterations, increased microglial M2-like gene expression, and clustering of microglia onto the brain vasculature. We determined that 4d LPS induces microglial morphological changes, clustering at the vasculature, and gene expression changes are dependent on endothelial IL-1R1, but not microglial IL-1R1. A novel observation was the induction of microglial IL-1R1 (mIL-1R1) following 4d LPS. The induced mIL-1R1 permits a unique response to central IL-1β: the mIL-1R1 dependent induction of IL-1R1 antagonist (IL-1RA) and IL-1β gene expression. Analysis of RNA sequencing datasets revealed that mIL-1R1 is also induced in neurodegenerative diseases.Discussion: Here, we have identified cell type-specific IL-1R1 mediated mechanisms, which may contribute to the neuroprotection observed in LPS preconditioning. These findings identify key cellular and molecular contributors in LPS-induced neuroprotection.Graphical Abstract: Keywords: BBB, neuroinflammation, perivascular microglia

In the last decade, mobile interactive electronic technical manuals - IETM - have become a modern means of competence support for personnel operating aircraft. The system of technical regulation distinguishes several classes of IETM according to the degree of their functional equipment. The highest classes of functional development of IETM presuppose their deep integration into on-board automation systems, the possibility of direct interface interaction with electronic diagnostic modules for accompanying products and wide integration of artificial intelligence tools. In turn, the inclusion of elements of artificial intelligence leads to a change in statistical approaches and principles for assessing the quality of the IETM themselves. This is due to the fact of continuous change in the consumer properties of IETM in the process of their use, the observed heteroscedasticity of the recorded values of indicators when assessing their quality. This article is devoted to the description of the methodology that allows to overcome the described specifics of the procedures for assessing the quality of IETM with elements of artificial intelligence.

The publication is a commented edition of the Moscow merchants Porokhovshchikovs’ family chronicler, discovered in the collection of Rostov antiquarian Andrey Alexandrovich Titov (1844–1911) in the Manuscripts Department of the National Library of Russia. The handwritten Notes are located on the last pages of the historical miscellanea of the second half of the 18th century from the Porkhovschikovs’ book collection. Annual records were kept from 1753 to 1803 — first by Petr Isaevich (1722–1801), and then by his son Andrey Petrovich (1771–?) Porokhovshchikov. The Notes is a typical for the merchant class of the 18th–19th centuries autobiographical work containing extensive information about the relatives and in-laws of the author, as well as about important historical events and persons. The chronicle makes it possible not only to reconstruct the social circles of the Porohovshchikovs, but also provides valuable biographical information about the Moscow and Astrakhan merchants of the second half of the 18th – early 19th centuries. This publication continues the article published in the journal “Dva veka russkoi klassiki” (“Two Centuries of Russian Classics”) and contains the results of the study of the monument.

Food processing (FP) industries are dominated by thermal inputs for food preservation. Such treatments can, however, contribute to some undesirable changes in the quality attributes and nutritional value of food. Non-thermal storage processes, on the other hand, have a negligible effect on the sensory consistency and nutritional status of food. Food preservation has used food with non-thermal methods with the aim of preserving the nutritious properties and physic-chemical features of foods. In this respect, the pulsed electrical field offers an alternate option for different food items, in particular liquid food products, in order to improve the protection and maintenance of new, consistent aspects of food. Similarly, this study emphasizes the promise of pulsed electric field technology as a useful method for preserving a variety of foods, with a focus on microbial inactivation. The key goal of this research is to find out how widely nonthermal FP equipment is used. Innovative technology can be able to help strike the right balance between protection and minimum processing, as well as sufficient economic constraints and superior efficiency.

E-commerce market development depends on the configuration of factors which both enable its further development, but might as well hinder its adoption by consumers. In particular, emerging markets provide numerous opportunities for e-commerce; however, they are also associated with specific barriers, limiting the potential for fully exploiting these opportunities. With an Internet audience of 93 mln people, the Russian emerging market represents the largest online audience in Europe, stimulating substantial e-commerce growth over the last decade. The main objective of this paper is to explore consumer perception of e-commerce adoption factors on two levels — the first are the macro-level factors, associated with the overall environment, institutional factors and trust; the second one is store-level factors, or factors associated with real consumer experiences. This multi-level approach reflects the complexity of consumer thinking about the market — both in terms of the evolving environment, offering opportunities to make decisions and make purchases; and real experience, where the factors are influencing particular consumer decisions and are weighted by consumers as pros and cons. Our study is based on a survey, using a sample of 3 387 respondents representing the consumer perspective. The findings reveal the structure of the driving and limiting factors, highlighting the core role of the trustworthiness and transparency of the e-commerce market players, delivery conditions and store-related risks.

We implemented a novel multi-resolution grid approach to direct current resistivity (DCR) modeling in 3-D. The multi-resolution grid was initially developed to solve the electromagnetic forward problem and helped to improve the modeling efficiency. In the DCR forward problem, the distribution of the electric potentials in the subsurface is estimated. We consider finite-difference staggered grid discretization, which requires fine grid resolution to accurately model electric potentials around the current electrodes and complex model geometries near the surface. Since the potential variations attenuate with depth, the grid resolution can be decreased correspondingly. The conventional staggered grid fixes the horizontal grid resolution that extends to all layers. This leads to over-discretization and therefore unnecessary high computational costs (time and memory). The non-conformal multi-resolution grid allows the refinement or roughening for the grid’s horizontal resolution with depth, resulting in a substantial reduction of the degrees of freedom, and subsequently, computational requirements. In our implementation, the coefficient matrix maintains its symmetry, which is beneficial for using the iterative solvers and solving the adjoint problem in inversion. Through comparison with the staggered grid, we have found that the multi-resolution grid can significantly improve the modeling efficiency without compromising the accuracy. Therefore, the multi-resolution grid allows modeling with finer horizontal resolutions at lower computational costs, which is essential for accurate representation of the complex structures. Consequently, the inversion based on our modeling approach will be more efficient and accurate.

We have developed a novel semiairborne frequency-domain electromagnetic (EM) system and successfully tested it within the DESMEX project. The semiairborne approach relies on the fact that part of the system is positioned on the ground and the rest is airborne. This allows us to take advantage of ground and airborne techniques. In particular, a high-moment transmitter can be installed on the earth’s surface, which enables us to inject and induce strong EM fields in the subsurface. Moreover, galvanic coupling is possible, which is an advantage if additional ground stations are deployed. The airborne receivers allow easier, significantly faster, and more uniform spatial coverage of the study area than the ground receivers. In our implementation, transmitters and electric field receivers are installed on the ground. Magnetic field sensors, such as commercially available fluxgate, total field magnetometers, and newly developed induction coils, are installed on a helicopter-towed bird. First, we describe the results of a semiairborne survey performed in a selected area with ancient mining located in the Saxothuringian zone near Schleiz, Germany. A 3D semiairborne inversion model represents several conductive anomalies, which agree well with the outcrop of alum shale formations at the surface. In addition, the shallow parts of the semiairborne model are compared with the result of an independent helicopter-borne survey, which consists of stepwise 1D models.