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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 - Monitoring Land Surface Hydrology Using Cygnss
摘要： The Cyclone Global Navigation Satellite System (CYGNSS) is a constellation of eight small satellites, each of which carries specialized GNSS receivers to record surface-reflected GNSS signals. The L-band signals recorded by CYGNSS have been shown to be sensitive to land surface hydrologic variables, including near-surface soil moisture and inundation extent. However, given certain conditions—such as vegetation cover and surface roughness, CYGNSS observations may be more or less sensitive to these variables. The pseudo-random sampling strategy used by CYGNSS presents new opportunities but also new challenges to the monitoring of land surface hydrology. This work, using South America as a case study, quantifies the ability of CYGNSS to monitor soil moisture and inundation extent for different vegetation and roughness conditions and describes how these measurements could be used to sense changes in surface hydrology over time.
关键词： CYGNSS,inundation,hydrology,soil moisture
更新于2025-09-23 15:21:21
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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 - Assessment of the Ground Polarimetry in Crops Estimated Using MB Sar Interferometry at C-Band
摘要： In this paper, polarimetric multi-baseline (MB) Synthetic Aperture Radar (SAR) Interferometry data are used to estimate the polarimetric ground component under vegetation. However, the solution of the applied separation algorithm is not unique and depends on the constraints in the regularization. First, the effect of this non-uniqueness is analyzed and then exploited to isolate a ground component with minimized influence of depolarizing scattering mechanisms. Using experimental MB SAR data acquired by DLR’s airborne sensor F-SAR, the polarimetric entropy and mean alpha angle of the isolated ground component are compared to the original polarimetry of the full image. Finally, the ground polarimetry is interpreted for changing soil moisture vegetation conditions in corn. To this purpose, three dates are compared characterized by 1) a change in soil moisture, 2) a change in vegetation cover or 3) a simultaneous change of soil moisture and vegetation cover.
关键词： Agricultural Vegetation,SAR Interferometry,Soil moisture
更新于2025-09-23 15:21:21
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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 - A First-Order Radiative Transfer Model for Global Soil Moisture Retrievals Under Vegetation Canopies
摘要： SMAP and SMOS missions estimate soil moisture using a zeroth-order radiative transfer model, the τ-ω model. Its simplifying assumption of a weakly scattering vegetation medium is insufficient in the presence of woody biomass, greater than 30% of the land surface. Here, a simplified first-order radiative transfer equation for use in retrieval algorithms is proposed. The inclusion of first-order scattering increases sensitivity to soil moisture especially for wet surfaces. The recently developed multi-temporal dual channel algorithm (MT-DCA) is implemented over Africa using both the τ-ω model and the proposed first-order equation with SMAP 36 km gridded brightness temperature measurements as inputs. The algorithm finds large changes in soil moisture mean and standard deviation in areas with woody vegetation and little change elsewhere. This implies that inclusion of first-order scattering can significantly change mean soil moisture retrievals and increase their temporal variability in regions with woody biomass.
关键词： Soil moisture,passive microwave radiometer,first-order scattering,SMAP
更新于2025-09-23 15:21:21
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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 - Recent Advances in Smap RFI Processing
摘要： The measurements made by the Soil Moisture Active/Passive (SMAP) mission are affected by the presence of Radio Frequency Interference (RFI) in the protected 1400-1427 MHz band. In SMAP data processing, the main protection against RFI is a sophisticated RFI detection algorithm which flags sub-samples in time and frequency that are contaminated by RFI and removes them before estimating the brightness temperature. This contribution presents two additional approaches that have been developed to address the RFI concern in SMAP. The first consists in locating sources of RFI, which can then be reported; once located, it becomes possible to report RFI sources to spectrum management authorities, which can lead to less RFI being experienced by SMAP in the future. The second is an additional RFI detection method that is based on detecting outliers in the spatial distribution of measured antenna temperatures.
关键词： Radio Frequency Interference (RFI),Soil Moisture Active/Passive (SMAP)
更新于2025-09-23 15:21:21
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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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Effect of Open Soil Surface Patterns on Soil Detectability Based on Optical Remote Sensing Data
摘要： Arable soils are subjected to the altering influence of agricultural and natural processes determining surface feedback patterns therefore affecting their ability to reflect light. However, remote soil mapping and monitoring usually ignore information on surface state at the time of data acquisition. Conducted research demonstrates the contribution of surface feedback dynamics to soil reflectance and its relationship with soil properties. Analysis of variance showed that the destruction surface patterns accounts for 71% of spectral variation. The effect of surface smoothing on the relationships between soil reflectance and its properties varies. In the case of organic matter and medium and coarse sand particles, correlation decreases with the removement of surface structure. For particles of fine sand and coarse silt, grinding changes spectral areas of high correlation. Partial least squares regression models also demonstrated variations in complexity, R2cv and RMSEPcv. Field dynamics of surface feedback patterns of arable soils causes 22–46% of soil spectral variations depending on the growing season and soil type. The directions and areas of spectral changes seem to be soil-specific. Therefore, surface feedback patterns should be considered when modelling soil properties on the basis of optical remote sensing data to ensure reliable and reproducible results.
关键词： digital soil mapping,remote sensing,spectral reflectance,surface feedback
更新于2025-09-23 15:21:21
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Indirect field technology for detecting areas object of illegal spills harmful to human health: application of drones, photogrammetry and hydrological models
摘要： The accumulation of heavy metals in agricultural soils is a serious environmental problem. The Campania region in southern Italy has higher levels of cancer risk, presumably due to the accumulation of geogenic and anthropogenic soil pollutants, some of which have been incorporated into organic matter. The aim of this study was to introduce and test an innovative, field-applicable methodology to detect heavy metal accumulation using drone-based photogrammetry and micro-rill network modelling, specifically to generate wetlands wetlands prediction indices normally applied at large catchment scales, such as a large geographic basin. The processing of aerial photos taken using a hexacopter equipped with fifth-generation software for photogrammetry allowed the generation of a digital elevation model (DEM) with a resolution as high as 30 mm. Not only this provided a high potential for the study of micro-rill processes, but it was also useful for testing and comparing the capability of the topographic index (TI) and the clima-topographic index (CTI) to predict heavy metal sedimentation points at scales from 0.1 to 10 ha. Our results indicate that the TI and CTI indices can be used to predict points of heavy metal accumulation for small field catchments.
关键词： drones,heavy metals soil pollution,Italy,health,topographic index,photogrammetry
更新于2025-09-23 15:21:21
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Influence of soil texture on the estimation of bare soil moisture content using MODIS images
摘要： Spectral behaviour of soil is strongly influenced by the soil texture as well as its nutrient content. Many attempts have so far been made to assess the soil moisture using soil reflectance in different bands of satellite images. In this paper, the investigations showed that the coarse texture soils did not show a profound relationship with the reflectance values that was in part due to its weak water storage capacity. Fine texture soils, on the contrary, showed better results which could be attributed to their higher water storage capacity and the capillary phenomenon. Finally, a linear regression model made of a combination of Land Surface Temperature (LST), Normalized Difference Water Index (NDWI) and Visible and Short-wave infrared Drought Index (VSDI) indices was proposed. The suggested method has improved the accuracy of the soil moisture content estimation up to 1% in general and the medium texture soil in particular. The results were compared with the performance of seven conventional soil moisture estimators method all using the Moderate Resolution Imaging Spectroradiometer (MODIS) data.
关键词： Soil moisture content,MODIS,soil texture,US-SCAN
更新于2025-09-23 15:21:01
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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 - Soil Moisture Retrieval by Combining Using Active and Passive Microwave Data
摘要： Active and passive microwave remote sensing have their particular characteristics. Active microwave is more sensitive to vegetation cover and surface soil roughness, while passive microwave is more sensitive to the surface soil moisture. A new retrieval algorithm has been proposed by using Aquarius and SMAP satellites’ active and passive microwave observations to retrieve soil moisture products in different spatial scales. The retrieval results of soil moisture have been verified with the ground observations of soil moisture and temperature measurement (SMTM) stations in Naqu, China. The advantages and disadvantages of the algorithm have also been evaluated to analyze the practical value of the new soil moisture retrieval algorithm.
关键词： soil moisture retrieval algorithm,passive microwave,soil moisture,active microwave,active and passive microwave remote sensing,Aquarius satellite
更新于2025-09-23 15:21:01
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The application of proximal visible and near-infrared spectroscopy to estimate soil organic matter on the Triffa Plain of Morocco
摘要： Soil organic matter (SOM) is a fundamental soil constituent. The estimation of this parameter in the laboratory using the classical method is complex time-consuming and requires the use of chemical reagents. The objectives of this study were to assess the accuracy of two laboratory measurement setups of the VIS-NIR spectroscopy in estimating SOM content and determine the important spectral bands in the SOM estimation model. A total of 115 soil samples were collected from the non-root zone (0-20 cm) of soil in the study area of the Triffa Plain and then analysed for SOM in the laboratory by the Walkley–Black method. The reflectance spectra of soil samples were measured by two protocols, Contact Probe (CP) and Pistol Grip (PG)) of the ASD spectroradiometer (350-2500 nm) in the laboratory. Partial least squares regression (PLSR) was used to develop the prediction models. The results of coefficient of determination (R2) and the root mean square error (RMSE) showed that the pistol grip offers reasonable accuracy with an R2 = 0.93 and RMSE = 0.13 compared to the contact probe protocol with an R2 = 0.85 and RMSE = 0.19. The near-Infrared range were more accurate than those in the visible range for predicting SOM using the both setups (CP and PG). The significant wavelengths contributing to the prediction of SOM for (PG) setup were at: 424, 597, 1432, 1484, 1830 ,1920, 2200, 2357 and 2430 nm, while were at 433, 587, 1380, 1431, 1929, 2200 and 2345 nm for (CP) setup.
关键词： soil organic matter,SOM analysis.,VIS-NIR spectroscopy,reflectance spectra,SOM estimation
更新于2025-09-23 15:21:01