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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Investigating the Relationship Between Shallow Groundwater, Soil Moisture and Land Surface Temperature Using Remotely Sensed Data
摘要： Shallow groundwater has a decisive impact on land surface temperature (LST) and soil moisture (SM). In the present paper relationship between shallow groundwater, SM and LST was studied. For this purpose, the groundwater level and soil moisture were measured in 59 and 39 locations respectively in the southwest of Iran, during June 2016, Simultaneous with the overpass of a Landsat 8 satellite from the study site. After necessary image processing the LST was retrieved from the Landsat image using the split window algorithm. Then relationship between retrieved LST and different field observation were studied. Results show that there is a significant relationship between the groundwater depth and SM with LST. These results indicate that shallow groundwater depth and soil moisture content could be estimated and mapped using the retrieved LST from the satellite imagery.
关键词： Remote Sensing,LST,Landsat 8,Shallow Groundwater,Soil moisture
更新于2025-09-23 15:23:52
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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 - Estimation of 1-Km All-Weather Land Surface Temperature Over the Tibetan Plateau
摘要： Land surface temperature (LST) immensely affects the energy balance and water cycle on the earth’s surface. Merging thermal infrared (TIR) and passive microwave (MW) remote sensing provides the possibility to obtain all-weather LST with moderate resolutions. However, due to difficulties in downscaling MW LST, current methods merging TIR LST and MW LST into such an all-weather LST are limited over large areas with very complicated land surfaces (e.g. the Tibetan Plateau). By fully considering the influence of the topography on estimation of merged LSTs, this study revises the recently-developed physical method for generating the 1-km all-weather LST and applies it over the Tibetan Plateau to merge MODIS (1 km) and AMSR2 (10 km) observations. Results show that the merged LST has accuracy of 0.99 K-3.22 K when validated against in-situ LSTs from five ground stations with various land cover types. This study would be beneficial for continuously monitoring LST and improving spatio-temporal resolutions for associated land surface process studies requiring high-quality all-weather LST over large scales.
关键词： MODIS,Spatial correlations,AMSR2,Land surface temperature (LST),Passive microwave remote sensing
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE SENSORS - Montreal, QC, Canada (2019.10.27-2019.10.30)] 2019 IEEE SENSORS - Evanescent field waveguide particle detector : Simulations concerning size and shape dependence
摘要： The midinfrared (MIR) spectral region (3–5 μm), which penetrates most haze layers in the atmosphere and is less sensitive to variations in atmospheric water vapor, seems to be appropriate for retrieving land surface temperature (LST). However, there are currently few studies of LST retrieval with MIR data because it is difficult to eliminate solar irradiance from the total energy measured in the MIR during the daytime. This paper proposes a physics-based method to retrieve LST from MODIS daytime MIR data. The bidirectional reflectivity describing the reflected solar direct irradiance is determined using the method by Tang and Li. The directional emissivity, representing the surface emitted radiance, is determined by a kernel-driven bidirectional reflectance distribution function model, i.e., RossThick-LiSparse-R. Intercomparisons using the MODIS-derived LST product MYD11_L2, for the Baotou experimental site in Urad Qianqi, Inner Mongolia, China, have a maximum root-mean-square error (RMSE) of 1.69 K and a minimum RMSE of 1.31 K, for four scenes of MODIS images. Furthermore, in situ LSTs measured at the Hailar field site in northeastern Inner Mongolia, China, were also used to validate the proposed method. Comparisons of the LSTs retrieved from MODIS daytime MIR data and those calculated using in situ measurements have a bias and RMSE of ?0.17 K and 1.42 K, respectively, which indicates that the proposed method can accurately retrieve LST from MODIS daytime MIR data.
关键词： MODIS,midinfrared (MIR),Daytime,land surface temperature (LST)
更新于2025-09-23 15:19:57
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Microstructural and Metallurgical Assessment of the Laser-Patterned Cemented Tungsten Carbide (WC-CoNi)
摘要： Cemented carbide is difficult to machine using traditional chip-removal methods due to its hardness. Electrical discharge machining (EDM) is the common method applied to shape cemented carbides because high geometric precision can be achieved. However, some important defects (pores, residual stresses or oxidation products) can be induced due to thermal reactions. Ultra-short pulse laser processing can also provide high precision and meanwhile effectively avoid these defects due to its short laser-matter reaction time. In this paper, three different patterns on WC-CoNi cemented carbides for tribological purposes, namely line-like patterns, dimples and grooves, have been created using different laser set-ups with pulse duration in the range of nanoseconds (10-9s), picoseconds (10-12s) and femtoseconds (10-15s). Microstructural and metallurgical changes of modified surfaces have been studied. Laser scanning microscopy (LSM) is conducted to measure the pattern dimensions. Focused ion beam (FIB) in combination with scanning electron microscope (SEM) is used to investigate the microstructural changes of the patterned materials.
关键词： Surface integrity,Laser surface patterning (LST),Cemented carbide,Ultra-short pulse laser processing
更新于2025-09-12 10:27:22
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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 Refined Generalized Split-Window Algorithm for Retrieving Long-Term Global Land Surface Temperature from Series NOAA-AVHRR Data
摘要： Long-term global land surface temperature (LST) is a very important data source for climate change study. By adding a quadratic term of two adjacent channels’ brightness temperature difference, this paper proposed to use a refined generalized split-window (GSW) algorithm to retrieve LST from series NOAA-AVHRR data. Results of the simulation analysis and the sensitive analysis indicated that the refined GSW method had a high retrieval accuracy and a robust performance. The overall root mean square errors (RMSEs) varied from 0.55 K to 0.59 K for NOAA 7-AVHRR to NOAA 19-AVHRR data. In terms of the wet atmosphere, the refined algorithm had a better ability than the GSW algorithm, and the proportion of sub-ranges with RMSE below 0.5 K was 61.7%. Most RMSE errors were within 0.2 K and 0.7 K for sensor noise (NEΔT) = 0.1 K and NEΔT = 0.2 K, respectively, compared with the cases of no NEΔT. Given the uncertainties of emissivity around 1%, the errors were mainly within [0.9K, 1.2K] for dry atmosphere and [0.3K, 0.7K] for wet atmosphere.
关键词： land surface temperature (LST),long-term,AVHRR-AVHRR,generalized split-window (GSW)
更新于2025-09-10 09:29:36
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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 - Estimation of Land Surface Temperature from Chinese Gaofen-5 Satellite Data
摘要： This work addressed the estimation of Land Surface Temperature (LST) from Chinese Gaofen-5 (GF-5) satellite Thermal Infrared (TIR) data, using a Generalized Split-Window (GSW) algorithm. The numerical values of the GSW coefficients were obtained using a statistical regression method from synthetic data simulated with an accurate atmospheric radiative transfer model MODTRAN 5 over a wide range of atmospheric and surface conditions. The LST, mean emissivity, and atmospheric Water Vapor Content (WVC) were divided into several tractable sub-ranges to improve the fitting accuracy. The experimental results showed that the combination of two adjacent channels CH8.20 (centered at 8.20 μm) and CH8.63 (centered at 8.63 μm) was comparable with the combination of two adjacent channels CH10.80 (centered at 10.80 μm) and CH11.95 (centered at 11.92 μm) for estimating LST using the GSW algorithm, with Root Mean Square Errors (RMSEs) below 0.8 K, provided that the Land Surface Emissivities (LSEs) are known. Particularly, for the high emissivity surfaces under wet and hot atmospheric conditions (WVC>3.0g/cm2), two not adjacent channels combination of CH8.63 and CH11.95 could also be used to estimate LST with RMSEs within 0.5 K.
关键词： Generalized Split-Window (GSW),channels combination,Land Surface Temperature (LST),Gaofen-5,Thermal Infrared (TIR)
更新于2025-09-10 09:29:36
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Comprehensive Remote Sensing || Land Surface Temperature Product Development for JPSS and GOES-R Missions
摘要： Land surface temperature (LST) is defined by the International LST and Emissivity Working Group as a measure of how hot or cold the surface of the Earth would feel to the touch. For ground-based, airborne, and space-borne remote sensing instruments it is the aggregated radiometric surface temperatures of all components within the sensor’s field of view in the direction of observation, or 'ensemble directional radiometric temperature.' As one of the most important parameters in the weather and climate system controlling surface heat and water exchange between the land and the atmosphere (Yu et al., 2012), LST has recently been listed as one of the Essential Climate Variables (ECVs) by the Global Climate Observation System (GCOS) of the World Meteorological Organization (WMO). Knowledge of the LST provides information on the temporal and spatial variations of the surface equilibrium state and is of fundamental importance in many applications (Li et al., 2013). This thermodynamic variable has been widely used in a variety of fields such as numerical weather prediction models and data assimilation systems (Meng et al., 2009; Zheng et al., 2012; Trigo et al., 2015), evapotranspiration evaluation (Sun et al., 2012; Galleguillos et al., 2011), irrigation and hydrological cycle particularly agricultural drought monitoring (Anderson et al., 2011, 2012; Karnieli et al., 2010), and urban heat island monitoring (Rajasekar and Weng, 2009; Weng et al., 2004).
关键词： ABI,LST Retrieval,Satellite LST Assessment,Land Surface Temperature,GOES-R,Split-Window Technique,Remote Sensing,VIIRS,JPSS
更新于2025-09-04 15:30:14
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Sulfur Dioxide (SO2) Monitoring Over Kirkuk City Using Remote Sensing Data
摘要： Air pollution mapping is now being an important issue to manage and enhance the environment of a city. The major problems of air pollution mapping is the data acquisition due to the high cost of instruments and the high spatial distribution requirements. This study aimed to monitor Sulfur Dioxide over Kirkuk city using Landsat-8 thermal bands to provide Department of Environment Kirkuk with low-cost Sulfur Dioxide concentration maps to better manage the city. The study used correlation analysis to find a relationship between Sulfur Dioxide ground-based measurements and satellite data. The ground-based measurements were collected from (17) stations distributed in Kirkuk city in January, 2014 using NOVA device to measure SO2 concentrations. The research showed a good correlation between ground- based measurements and satellite data with (R2=0.48 for band 11 and R2= 0.52 for band 10). Therefore, the study resulted that with band 10 of Landsat-8 data, better SO2 can be monitored than using band 11. It is recommended to other researchers to investigate the ability of free remote sensing data to monitor all elements that specify the air quality of a city.
关键词： LST,Environment,Kirkuk city,SO2,TIRS,Remote sensing,GIS,Air pollution,Sulfur dioxide
更新于2025-09-04 15:30:14
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[Lecture Notes in Electrical Engineering] Proceedings of the Tiangong-2 Remote Sensing Application Conference Volume 541 (Technology, Method and Application) || Analysis of Slope and NDVI Effects on Land Surface Temperature Retrieval Accuracy in Mountain Area Based on WIS Data of Tiangong-2
摘要： The relationship between land surface temperature (LST) and Normalized Difference Vegetation Index (NDVI) is evaluated in mountain areas using the Wide-band Imaging Spectrometer (WIS) data on Chinese Tiangong-2 (TG-2) Space Lab. The WIS is composed of three regions: Visible Near-Infrared (VNIR) (14 channels), Short-Wave Infrared (SW) (2 channels), and Thermal Infrared (TIR) (2 channels). The two TIR channels, T1 (8.125–8.825 lm) and T2 (8.925–9.275 lm) have not been fully exploited to extract LST. Thus, a modi?ed split window method was proposed to retrieve LST and evaluated by comparing to the MODIS LST product. Then, the LST retrieval accuracy affected by slope and NDVI is analyzed. Results show that: (a) TG-2 LST is positively correlated to MODIS LST (R2 = 0.74) but overestimated (about 3.5 K); further improvement on the split window method is still needed; (b) the TG-2 LST accuracy is different in vegetation and non-vegetation area, where non-vegetation area with small NDVI standard deviation has better agreement between MODIS LST and TG-2 than vegetation area; (c) the LST retrieval accuracy in vegetation area is independent on slopes; while increasing with the slope in non-vegetation area.
关键词： NDVI,Split-window algorithm,WIS data of Tiangong-2,TIR,LST retrieval,Slope
更新于2025-09-04 15:30:14