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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Multi-Frequency Microwave Resonance Cavity for Nondestructive Core Plug Measurements
摘要： This work describes the theory, design and testing of a multi-frequency microwave cavity. The cavity measures the complex permittivity of core plugs of rocks, consolidated soil or sea ice. The core plugs can have commercially available diameter dimensions (0.02 meters - 0.038 meters) and for maximum height of 0.055 meters. The cavity measures the complex permittivity at five resonant frequencies between 1 GHz and 3.5 GHz of the TM0np mode. An infrared temperature sensor measures the temperature of the core plug under testing. This cavity allows for a more accurate characterization of the core composition. Initial complex permittivity measurements of six different shale core plugs were conducted. Results show that permittivity spectra can be correlated to the clay content and total organic content (TOC) of the shales. The latter is a function of the maturity of the rock. Moreover, initial results indicate the importance of water and salinity on shale samples.
关键词： sea ice,dielectric measurement,geology,Permittivity measurement,soil,well logging,geophysical measurement,microwave measurements
更新于2025-09-23 15:21:21
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A new approach to non-linear multivariate calibration in laser-induced breakdown spectroscopy analysis of silicate rocks
摘要： In this paper a new approach to quantitative Laser-Induced Breakdown Spectroscopy (LIBS) analysis of silicate rocks is presented. The method is adapted from the Franzini and Leoni algorithm, a method widely used in X-Ray Fluorescence analysis for correcting the matrix effects in the determination of the composition of geological materials. To illustrate the features of the new method proposed, nine elements were quantified in 19 geological standards by building linear univariate calibration curves, linear multivariate calibration surfaces (PLS) and using Artificial Neural Networks. The results were then compared with the predictions derived from the application of the algorithm here proposed. It was found that the Franzini and Leoni approach gives results much more precise than linear uni- and multivariate approaches, and comparable with the ones derived from the application of Artificial Neural Networks. A definite advantage of the proposed approach is the possibility of building multivariate non-linear calibration surfaces using linear optimization algorithms, a feature which makes the application of the Franzini and Leoni method in LIBS analysis much simpler (and controllable) with respect to the algorithms based on Artificial Neural Networks.
关键词： LIBS,Artificial Neural Networks,Multivariate Analysis,Geology,PLS
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE Innovative Smart Grid Technologies - Asia (ISGT Asia) - Chengdu, China (2019.5.21-2019.5.24)] 2019 IEEE Innovative Smart Grid Technologies - Asia (ISGT Asia) - Designs and Applications for the Controller Parameters of the Photovoltaic System
摘要： Many economically important minerals have absorption features in the short-wave infrared (SWIR; 2000–2500 nm). Sensors which measure this part of the spectrum cannot detect the wavelength minimum of a feature at ～900 nm (F900), indicative of ferric iron mineralogy. A method based on Gaussian processes (GPs) was developed and compared with multiple linear regression (MLR) to estimate the wavelength position of F900 from SWIR data (1002–1355 nm). SWIR data with different signal-to-noise ratios were acquired from crushed rock samples by a nonimaging spectrometer and an imaging spectrometer. GP estimates of wavelength position were converted to the proportion of goethite using coefficients from a regression of the proportion of goethite determined from X-ray diffraction (XRD) on wavelength position measured directly from spectra. GP-estimated wavelength positions were within the 2-nm and ～4-nm root-mean-square error of measurements made directly from spectra for nonimaging and imaging spectrometer data, respectively. Proportions of goethite derived from these estimates were respectively within 4% and 6% of the values measured by XRD. MLR performed poorly compared to GPs when applied to data with no added noise and failed when applied to data with added noise or to imaging spectrometer data. These findings indicate that the wavelength position of F900—an indicator of ferric iron mineralogy—can be estimated from data acquired at SWIR wavelengths (1002–1355 nm). This opens up possibilities for using a single (SWIR) sensor to acquire information on ferric iron mineralogy (using F900) and other minerals with diagnostic absorptions between 1000 and 2500 nm.
关键词： geology,infrared spectroscopy,iron,image sensors,remote sensing,Gaussian processes (GPs),mining industry,Electromagnetic radiation,spectral analysis,signal processing
更新于2025-09-19 17:13:59
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Abrupt Change in Forest Height along a Tropical Elevation Gradient Detected Using Airborne Lidar
摘要： Most research on vegetation in mountain ranges focuses on elevation gradients as climate gradients, but elevation gradients are also the result of geological processes that build and deconstruct mountains. Recent ?ndings from the Luquillo Mountains, Puerto Rico, have raised questions about whether erosion rates that vary due to past tectonic events and are spatially patterned in relation to elevation may drive vegetation patterns along elevation gradients. Here we use airborne light detection and ranging (LiDAR) technology to observe forest height over the Luquillo Mountain Range. We show that models with different functional forms for the two prominent bedrock types best describe the forest height-elevation patterns. On one bedrock type there are abrupt decreases in forest height with elevation approximated by a sigmoidal function, with the in?ection point near the elevation of where other studies have shown there to be a sharp change in erosion rates triggered by a tectonic uplift event that began approximately 4.2 My ago. Our ?ndings are consistent with broad geologically mediated vegetation patterns along the elevation gradient, consistent with a role for mountain building and deconstructing processes.
关键词： long-term ecological research,geology,critical zone observatory,three-dimensional structure,vegetation,10Be,erosion,active remote sensing,tectonics,ecology
更新于2025-09-09 09:28:46
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Mini-UAV-Borne Hyperspectral Remote Sensing: From Observation and Processing to Applications
摘要： In recent years, with the rapid development of unmanned aerial vehicles (UAVs) and lightweight hyperspectral imaging (HSI) sensors, mini-UAV-borne hyperspectral remote sensing (HRS) systems have been developed and demonstrate great value and application potential. Compared to spaceborne and airborne HSI systems, mini-UAV-borne HSI systems come with relatively low manufacturing and running costs and have thus become a new research focus in the field of HRS. This article focuses on recent developments in UAV-borne HRS, including UAV platforms, miniaturized hyperspectral sensors, system integration, data observation, and preprocessing. In addition, successful application cases in the domains of agriculture, forestry, geology, and environmental monitoring are introduced, and we discuss current UAV-borne systems and their developing trends.
关键词： forestry,environmental monitoring,hyperspectral remote sensing,HSI,geology,agriculture,UAV
更新于2025-09-04 15:30:14