scholarly journals Near real-time field measurements of δ13C in CO2 from volcanoes

2017 ◽  
Vol 79 (8) ◽  
Author(s):  
John Stix ◽  
Gregor Lucic ◽  
Kalina Malowany
Keyword(s):  
2021 ◽  
Author(s):  
Kyubo Noh ◽  
◽  
Carlos Torres-Verdín ◽  
David Pardo ◽  
◽  
...  

We develop a Deep Learning (DL) inversion method for the interpretation of 2.5-dimensional (2.5D) borehole resistivity measurements that requires negligible online computational costs. The method is successfully verified with the inversion of triaxial LWD resistivity measurements acquired across faulted and anisotropic formations. Our DL inversion workflow employs four independent DL architectures. The first one identifies the type of geological structure among several predefined types. Subsequently, the second, third, and fourth architectures estimate the corresponding spatial resistivity distributions that are parameterized (1) without the crossings of bed boundaries or fault plane, (2) with the crossing of a bed boundary but without the crossing of a fault plane, and (3) with the crossing of the fault plane, respectively. Each DL architecture employs convolutional layers and is trained with synthetic data obtained from an accurate high-order, mesh-adaptive finite-element forward numerical simulator. Numerical results confirm the importance of using multi-component resistivity measurements -specifically cross-coupling resistivity components- for the successful reconstruction of 2.5D resistivity distributions adjacent to the well trajectory. The feasibility and effectiveness of the developed inversion workflow is assessed with two synthetic examples inspired by actual field measurements. Results confirm that the proposed DL method successfully reconstructs 2.5D resistivity distributions, location and dip angles of bed boundaries, and the location of the fault plane, and is therefore reliable for real-time well geosteering applications.


2022 ◽  
Vol 122 ◽  
pp. 104350
Author(s):  
Gang Zheng ◽  
Yiming Su ◽  
Yu Diao ◽  
Yubo Zhao ◽  
Hao Chen ◽  
...  

2013 ◽  
Vol 1 (1) ◽  
Author(s):  
Joko Setiadi

Abstrak Penggunaan receiver GPS RTK (Real Time Kinematic) pada metode ekstraterestrial untuk penentuan posisi titik saat ini sudah banyak diterapkan. Penelitian ini bertujuan mengkaji sampai sejauh mana ketelitian posisi titik yang diperoleh dari hasil pengukuran secara ekstraterestrial menggunakan GPS RTK untuk pemetaan bidang-bidang tanah berikut kekurangan dan kelebihannya. Dari hasil pengukuran didapat ketelitian rata-rata hasil pengukuran posisi titik menggunakan GPS RTK dibandingkan dengan menggunakan alat ETS (Electronic Total Station) adalah sebesar 0,214 m sehingga dapat diterapkan untuk pembuatan peta skala 1 : 500. Untuk daerah yang terbuka, pengukuran bidang tanah menggunakan GPS RTK memerlukan waktu dua kali lebih cepat dibandingkan dengan ETS. Walaupun GPS RTK mempunyai keunggulan dalam hal efisiensi proses pengukuran di lapangan sehingga dapat mempersingkat waktu pengukuran, akan tetapi memiliki kekurangan dalam hal ketelitian data terutama pada area pengukuran yang tertutup. Kata kunci: GPS RTK, ETS, posisi titik, ekstraterestrial.   Abstract The use of RTK GPS receiver (Real Time Kinematic) on extraterrestrial method for point positioning h widely applied. The purpose of this study is to examine the point position accuracy obtained from the measurements using GPS RTK for extraterrestrial mapping plots, including its advantages and disadvantages. Measurement accuracy of the results obtained from the average measurement point positioning using GPS RTK compared using the ETS tool is equal to 0.214 m, so that it can be applied for map making of scale 1: 500. For open areas, field measurements using GPS RTK can be performed by two times faster than using ETS. Although GPS RTK has advantages in terms of measurements process efficiency in the field so as to shorten the time of measurement, but has shortcomings in terms of accuracy of the data, especially in an enclosed area measuring. Keywords: GPS RTK , ETS, point position, extraterrestrial.


2018 ◽  
Vol 27 (6) ◽  
pp. 413 ◽  
Author(s):  
Xihua Yang ◽  
Qinggaozi Zhu ◽  
Mitch Tulau ◽  
Sally McInnes-Clarke ◽  
Liying Sun ◽  
...  

Wildfires in national parks can lead to severe damage to property and infrastructure, and adverse impacts on the environment. This is especially pronounced if wildfires are followed by intense storms, such as the fire in Warrumbungle National Park in New South Wales, Australia, in early 2013. The aims of this study were to develop and validate a methodology to predict erosion risk at near real-time after storm events, and to provide timely information for monitoring of the extent, magnitude and impact of hillslope erosion to assist park management. We integrated weather radar-based estimates of rainfall erosivity with the revised universal soil loss equation (RUSLE) and remote sensing to predict soil loss from individual storm events after the fire. Other RUSLE factors were estimated from high resolution digital elevation models (LS factor), satellite data (C factor) and recent digital soil maps (K factor). The accuracy was assessed against field measurements at twelve soil plots across the Park and regular field survey during the 5-year period after the fire (2013–17). Automated scripts in a geographical information system have been developed to process large quantity spatial data and produce time-series erosion risk maps which show spatial and temporal changes in hillslope erosion and groundcover across the Park at near real time.


2020 ◽  
Vol 59 (03) ◽  
pp. 1
Author(s):  
Ze-Hou Yang ◽  
Yong-Ke Zhang ◽  
Jie Zhou ◽  
Yong Chen ◽  
Guo-Juan Zhang ◽  
...  

2006 ◽  
Vol 21 (4) ◽  
pp. 222-227 ◽  
Author(s):  
Michael G. Wing ◽  
Richard Karsky

Abstract Accuracy requirements for forested resource measurements can vary greatly depending on analysis and management objectives. Technologies that present efficiencies for reliable measurement collection may help organizations better meet data requirements. We tested the accuracy and reliability of a mapping-grade GPS in a variety of forested conditions in western Oregon. Our objectives were to measure the performance of a GPS operating in a standard configuration and also with real-time US Coast Guard Beacon signals. We also examined the influence of postfield differential corrections and the number of GPS points collected on measurement accuracy and reliability. We found measurement accuracies between 1 and 4 m from true position depending on the amount of canopy closure and the type of GPS configuration. Our results indicated that both standard-mode GPS and US Coast Guard Beacon signals can produce very accurate measurements in open-canopy conditions but are less reliable in young-forest conditions. Postprocessing of field measurements generally yielded improved measurements in young-forest settings but led to slightly reduced accuracies for US Coast Guard Beacon data collected in open-canopy settings. Our results also indicated that collecting a greater number of points does not necessarily lead to improved measurement accuracies. West. J. Appl. For. 21(4):222–227.


Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2095
Author(s):  
Isis Frausto-Vicencio ◽  
Alondra Moreno ◽  
Hugh Goldsmith ◽  
Ying-Kuang Hsu ◽  
Francesca M. Hopkins

In this study, we test the performance of a compact gas chromatograph with photoionization detector (GC-PID) and optimize the configuration to detect ambient (sub-ppb) levels of benzene, toluene, ethylbenzene, and xylene isomers (BTEX). The GC-PID system was designed to serve as a relatively inexpensive (~10 k USD) and field-deployable air toxic screening tool alternative to conventional benchtop GCs. The instrument uses ambient air as a carrier gas and consists of a Tenax-GR sorbent-based preconcentrator, a gas sample valve, two capillary columns, and a photoionization detector (PID) with a small footprint and low power requirement. The performance of the GC-PID has been evaluated in terms of system linearity and sensitivity in field conditions. The BTEX-GC system demonstrated the capacity to detect BTEX at levels as high as 500 ppb with a linear calibration range of 0–100 ppb. A detection limit lower than 1 ppb was found for all BTEX compounds with a sampling volume of 1 L. No significant drift in the instrument was observed. A time-varying calibration technique was established that requires minimal equipment for field operations and optimizes the sampling procedure for field measurements. With an analysis time of less than 15 min, the compact GC-PID is ideal for field deployment of background and polluted atmospheres for near-real time measurements of BTEX. The results highlight the application of the compact and easily deployable GC-PID for community monitoring and screening of air toxics.


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