Research on Scale Model of Typical Tension String of UHVDC Transmission Lines under Ice-Shedding Loads

Tension insulator string is one of the important components of transmission lines and it needs to have enough mechanical strength to transfer the load between conductors and towers. However, due to the large size of the tension insulator strings, it is usually impossible to carry out the true type experiments. In this paper, the dimensional analysis was adopted to establish the mapping scale models of typical tension strings, namely 8N42-50100-55P at first. Then, the load scaling ratios of three typical tension insulator strings were obtained based on the results of the ice shedding calculation on an actual UHVDC transmission lines. Finally, the dynamic experiments of the scale tension insulator strings were carried out to access the feasible of technical route and to provide a technical support for the following research.

Regional Geologic Mapping of the Oxia Planum Landing Site for the Exomars Mission

<p>In 2023, the ExoMars mission will deploy a stationary surface platform and a rover in Oxia Planum (OP), a region at the transition between the heavily cratered highlands of Mars and the ancient and filled impact basin, Chryse Planitia. While the fundamental geologic characteristics of the area have been investigated during the landing site selection process, detailed geologic or morpho-stratigraphic mapping is still missing. To fill this knowledge gap, two complementary mapping approaches were initiated by the ExoMars RSOWG: (1) Local HiRISE-scale mapping of the landing ellipse(s) area (reported elsewhere: Sefton-Nash et al., <em>LPSC 2021</em>, #1947). (2) Regional mapping at ~CTX-scale [this study] will provide a synoptic view of the wider landing site within OP, enabling the contextualization of the units within the stratigraphy of western Arabia Terra and Chryse Planitia, and a comparison to other sites with similar key geologic and physiographic characteristics. It is also expected that this map will serve as a geologic reference throughout the mission and subsequent data analysis. The study area is located between 16.5°N and 19.5°N, and 334°E to 338°E. The data sets used for mapping include HRSC, THEMIS IR (day and night), CTX, and CaSSIS. Mapping scale in a GIS environment is 1:100,000, which will result in a final printable map at a scale of 1:1M.</p><p>Mapping started in mid-October 2019. Overall, the identified map units are very similar to those described by Quantin et al. (<em>Astrobiology</em>, vol. <strong>21</strong>, 2021): The spatially most widespread units are the phyllosilicate-bearing unit that is the prime ExoMars target (with distinctly enhanced THEMIS nighttime temperatures when compared to its surroundings), a dark resistant unit of possibly volcanic or sedimentary origin, and a mantling unit that was likely emplaced by eolian processes. Multiple channels of various morphology and degradation state as well as sedimentary fan-shaped deposits (with low nighttime temperatures) imply a diverse and possibly long-lived history of surface runoff, perhaps accompanied or replaced by groundwater processes such as sapping. Inverted landforms (channels, impact craters) are the result of intense erosion. Additional mapped features include tectonic structures such as wrinkle ridges and lobate scarps (delineating a basin-like depression in the central mapping area), remnant erosional buttes in the northwestern portion of the mapping area (i.e. towards Chryse Planitia), craters and their ejecta blankets, and fields of eolian bedforms and secondary craters.</p><p>At the time of writing, the mapping is in its final stage, but some contacts still need to be refined. Overall, the mapping confirms previous geologic analyses. However, some features (e.g., contractional structures, channels, possible sapping landforms) need further attention as the may provide important constraints on the tectonic and aqueous evolution of the ExoMars landing area. A comparison to a distant, but geologically very similar site in Xanthe Terra, southeast of the Hypanis fan-shaped deposits, may enable testing of hypotheses raised by the geologic mapping of OP (Früh et al., <em>LPSC 2021</em>, #1977).</p>

Regional Geologic Mapping of the Oxia Planum Landing Site for ExoMars

<p><span>The ExoMars mission will deploy a stationary surface platform and a rover in Oxia Planum (OP), a region at the transition between the heavily cratered highlands of Mars and the ancient and filled </span><span><span>impact basin, Chryse Planitia. While the fundamental geologic characteristics of the area have been investigated during the landing site selection process, detailed geologic or morpho-stratigraphic mapping is still missing. To fill this knowledge gap, two complementary mapping approaches were initiated by the ExoMars RSOWG: (1) Local HiRISE-scale mapping of the landing ellipse(s) area (reported elsewhere: Sefton-Nash et al., LPSC 2020). (2) Regional mapping at ~CTX-scale [this study] will provide a more synoptic view of the wider landing site within OP</span></span><span>, enabling the contextualization of the units within the stratigraphy of western Arabia Terra and Chryse Planitia, and a comparison to other sites with similar key geologic and physiographic characteristics. It is also expected that this map will serve as a geologic reference throughout the mission and subsequent data analysis. </span></p><p><span>The study area is located between 16.5°N and 19.5°N, and 334°E to 338°E. </span><span><span>The data sets used for mapping include HRSC, THEMIS IR (day and night), CTX, and CaSSIS. Mapping scale in a GIS environment is 1:100,000, which will result in a final printable map at a scale of 1:1M. </span></span><span>Mapping started in mid-</span><span><span>October 2019. Overall, the identified map units are very similar to those described by Quantin et al. (Astrobiology, submitted): The </span></span><span>spatially most widespread units are the phyllosilicate-bearing unit that is the prime ExoMars target (with distinctly enhanced THEMIS nighttime temperatures when compared to its surroundings), a dark resistant unit of possibly </span><span><span>volcanic or sedimentary origin, and a mantling unit that was likely emplaced by eolian processes. Multiple channels of various morphology and degradation state as well as sedimentary fan-shaped deposits (with low nighttime temperatures) imply a diverse and possibly long-lived history of surface runoff, perhaps accompanied or replaced by groundwater processes such as sapping. Inverted landforms (channels, impact craters) are the result of intense erosion. Additional mapped features include tectonic structures such as wrinkle ridges and lobate scarps (delineating a basin-like depression in the central mapping area), remnant erosional buttes </span></span><span>in the northwestern portion of the mapping area (i.e. towards Chryse Planitia), craters and their ejecta blankets, and fields of eolian bedforms and secondary craters. </span></p><p><span>At the time of writing, the mapping is incomplete and only initial and limited conclusions can be drawn. Overall, the mapping confirms previous geologic analyses. However, some features (e.g., contractional structures, channels, possible sapping landforms) need further attention as the may provide important constraints on the tectonic and aqueous evolution of the ExoMars landing area. A comparison to a distant, but geologically very similar site in Xanthe Terra, southeast of the Hypanis fan-shaped deposits, may enable testing of hypotheses raised by the geologic mapping of OP.</span></p>

Comparative analysis of satellite images obtained by spacecraft “Canopus-V” and “Aist-2D”

A comparative analysis of the remote sensing data, obtained by spacecrafts “Canopus-V” and “Aist-2D”, in terms of determining their actual spatial resolution – the smallest linear size of the terrain object that can be transmitted by the image. Within the researches of studied space imagery structural transfer properties the calculations of their general and local contrast for different types of underlying surface were performed. In particular, it was shown, that despite the smaller ground sampling interval (GSI), images, obtained by “Aist-2D”, are comparable in their structural transfer characteristics to the images of “Canopus-V” because of the greater blurring. However, “Canopus-V” images have a disadvantage – the artifacts due to direct solar reflection from smooth (mirror) surfaces, which “Aist-2D” images do not have. Basing on the obtained values of structural transfer characteristics and the requirements of the Instructions on photogrammetric work for digital topographic maps and plans creation, the mapping scale, corresponding the attainable accuracy of measurements, made by images, obtained by spacecrafts “Canopus-V” and “Aist-2D”, is determined. The conclusions about the comparability of considered space imagery structural transfer characteristics, the advantages and disadvantages in terms of their photographic quality, as well as the possibility of their use for mapping purposes are formulated.

ACCURACY EVALUATION OF VARIOUS SATELLITE IMAGERY PRODUCTS FOR LARGE SCALE TOPOGRAPHIC MAPPING

<p><strong>Abstract.</strong> DEM and ortho-imageries are building blocks for topographic mapping and satellite imageries are prime source of data for inaccessible terrain. When the required mapping scale is of the order 10k or higher, the accuracy needed is also of higher order. It becomes imperative to evaluate the accuracy of available high resolution DEMs and corresponding imageries to provide quality products for mapping. The present study is encouraged by the fact that not every place of our earth is accessible, so an assessment of satellite data products is required for precise mapping. Here, the accuracy assessment has been carried out in terms of RMSE, SD, CE90 and LE90 of various products viz. Carosat-1, Cartosat-2E, Worldview-2 (WV), Vricon, Pleiades, ALOS-World-3D (AW3D) ASTER, SRTM with Yahoo image. GCPs acquired by DGPS field survey were used to evaluate the products. The results have demonstrated that Vricon 0.5<span class="thinspace"></span>m ortho-image provides the best RMSE (3.42) and CE90 (4.65); however, WV and Vricon DEM turns out to be best with RMSE of 2.20<span class="thinspace"></span>m and 2.90<span class="thinspace"></span>m respectively. Both products are suitable for large scale topographic mapping. The data can be used for inaccessible terrain where GCPs are not available. However, Cartosat-1 and Cartosat-2E can be used where good GCPs are available. The outcome of study can be used for planning of data suitability for scale variant mapping and inaccessible terrain mapping.</p>

LAYOUT SLAM WITH MODEL BASED LOOP CLOSURE FOR 3D INDOOR CORRIDOR RECONSTRUCTION

In this paper, we extend a recently proposed visual Simultaneous Localization and Mapping (SLAM) techniques, known as Layout SLAM, to make it robust against error accumulations, abrupt changes of camera orientation and miss-association of newly visited parts of the scene to the previously visited landmarks. To do so, we present a novel technique of loop closing based on layout model matching; i.e., both model information (topology and geometry of reconstructed models) and image information (photometric features) are used to address a loop-closure detection. The advantages of using the layout-related information in the proposed loop-closing technique are twofold. First, it imposes a metric constraint on the global map consistency and, thus, adjusts the mapping scale drifts. Second, it can reduce matching ambiguity in the context of indoor corridors, where the scene is homogenously textured and extracting sufficient amount of distinguishable point features is a challenging task. To test the impact of the proposed technique on the performance of Layout SLAM, we have performed the experiments on wide-angle videos captured by a handheld camera. This dataset was collected from the indoor corridors of a building at York University. The obtained results demonstrate that the proposed method successfully detects the instances of loops while producing very limited trajectory errors.

BEBAN GANDA PENGELOLAAN AIR TANAH DI KABUPATEN/KOTA PASCA PEMBATALAN UU NO 4/2007 TENTANG SUMBER DAYA AIR: ILUSTRASI DARI KOTA BANDUNG

AbstrakIndonesia sedang memiliki beban ganda dalam menyelesaikan masalah pengelolaan sumber daya air, khususnya air tanah. Selain karena pembatalan UU No. 7/2004, juga karena pengalihan kewenangan pengelolaan dari pemerintah kabupaten/kota ke pemerintah provinsi sebagai dampak dari UU No. 23/2014. Karena proses komunikasi antara provinsi dan kabupaten/kota tidak mulus, karena berbagai alasan, akibatnya regulasi tidak kunjung dibuat. Pada akhirnya kondisi air tanah akan semakin buruk. Makalah ini mencoba mendudukkan kembali berbagai aspek pengelolaan air tanah yang telah dirumuskan sebelumnya dan masih relevan untuk dijalankan saat ini. Kemudian dipilihlah aspek konservasi dan pemberdayaan sebagai aspek yang dapat dikerjasamakan antara pemerintah provinsi dan pemerintah kabupaten/kota, karena: aspek ini lebih berkaitan dengan aspek monitoring atau pemantauan. Yang mana, pemantauan akan lebih baik dilakukan oleh pemerintah kabupaten/kota karena skala pemetaan yang lebih rinci, dibanding bila dilakukan pada skala provinsi. Selain itu instrumentasi pemantauan yang dimiliki oleh organ tingkat kabupaten/kota lebih lengkap dibanding pemerintah provinsi.Kata kunci: Regulasi, Pengelolaan Air Tanah, Cekungan Air TanahAbstractIndonesia currently has a double burden in solving the problem of water resources, particularly groundwater. In addition to the cancellation of Law No. 7/2004, as well as the transfer of management authority of district/city government to the provincial government as a result of Law No. 23/2014. Due to the communication process between the provincial and district /city is not good, for various reasons, not being made as a result of regulation. Ultimately groundwater conditions will be getting worse. This paper tries to reinstate the various aspects of groundwater management has been formulated previously and are still relevant to the current run. Then chosen aspects of conservation and empowerment as an aspect to cooperation between the provincial and district /city government, because: this aspect is more related to aspects of monitoring. Which, monitoring would be better done by the district /city for more detailed mapping scale. Besides monitoring instrumentation owned by organs of district/municipal level is more complete than the provincial government.Keywords: Regulation, Groundwater Management, Groundwater Basin

GEOMETRIA, PETROGRAFIA E DEFORMAÇÃO DE CORPOS ULTRAMÁFICOS METAMORFISADOS DA REGIÃO DE SANTA RITA DE OURO PRETO, MG, BRASIL.

A região de Santa Rita de Ouro Preto é historicamente conhecida pelo artesanato em pedra-sabão, designação popular do esteatito, cujo conteúdo de talco é superior a 75% e é produto do metassomatismo de rochas ultramáficas peridotíticas. Assim, o estabelecimento da geometria externa dos corpos ultramáficos metamorfisados, de onde se extrai o esteatito, está diretamente relacionado ao melhor aproveitamento econômico dos mesmos. Um modelo inicialmente proposto de zoneamento litológico, de geometria externa circular, cuja diferenciação petrográfica do núcleo em direção à borda, reflete em um núcleo quimicamente menos modificado. No presente trabalho, tal zoneamento litológico em linhas gerais se mantem, com suaves modificações. Entretanto, quanto a sua morfologia, propõe-se, uma geometria assimétrica para os corpos ultramáficos metamorfisados encontrados na região de Santa Rita de Ouro Preto e arredores, uma vez que a geometria arrendondada desconsidera a ação de um campo de tensões. Por meio de mapeamento geológico, em escala 1:10.000, caracterizaram-se corpos com geometria na forma de pods, cuja associação com diques de anfibolito reflete as direções aproximadas, NE-SW, de um campo de tensões, uma vez que os pods apresentam alinhamento NW-SE. Esses corpos foram deformados e sua geometria, em mapa observada na forma de “diques”, reflete, de fato, a direção principal de alongamento dos pods. Neste contexto, esse manuscrito visa fornecer subsídios para o melhor entendimento dos processos deformacionais ocorridos, da geometria e do posicionamento tectônico destas rochas.Palavras-chave: geometria assimétrica, deformação, esteatito, Santa Rita de Ouro Preto, Quadrilátero Ferrífero. ABSTRACT: GEOMETRY, PETROGRAPHY AND DEFORMATION OF METAMORPHOSED ULTRAMAFIC BODIES FROM SANTA RITA DE OURO PRETO REGION, MG, BRASIL. The Santa Rita de Ouro Preto district is historically known for its handcraft using “soapstone”, a popular rock with low stiffness due to its high talc percentage, upper 75 wt. %. These rocks are named steatites and they are generated when ultramafic peridotites are submitted to metassomatic processes. Then, establishing the external geometry of the metamorphosed ultramafic bodies from which the soapstone is exploited, a better economical exploitation of those rocks could be attained. A proposed model based on lithological zoning with circular external geometry where there is a petrographic differentiation from the core to the rim with less chemical differentiation at the core. The lithological zoning is maintained in this work as previously proposed, with small restrictions. However, we propose an asymmetric geometry to ultramafic metamorphic bodies near the Santa Rita district and surrounding areas, once the rounded zoning model does not consider action of field stress. Through geological mapping (scale: 1:10,000) an external geometry of ultramafic metamorphic bodies known as pods were characterized. This feature has a common association with dikes of mafic metamorphic rocks, such as amphibolites; this suggests that a field stress acted during the formation of those bodies. The pods present an alignment in the NW-SE orientation which agrees with the general vergence of the field stress, approximately NE-SW. The ultramafic metamorphic bodies were deformed and their geometries are observed in map as dikes, but they reflect the main direction of pods elongation. In this sense, the new geometry model supplies information to the better understanding of deformational processes that occurred in the Santa Rita de Ouro Preto region. This will also help determine the geometry of the pods and how ultramafic metamorphic rocks are tectonically positioned.Keywords: asymmetric geometry, strain, soapstone, Santa Rita de Ouro Preto district, Quadrilátero Ferrífero