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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 - Leaf Water Status from Lab Estimates of VIS-NIR Reflectance and Transmittance
摘要： Remotely sensing the water status of plant canopies remains a long term goal of remote sensing research. Established approaches involve measurements in the thermal infrared and the 900-2000nm reflective infrared. Less popular UV-visible-NIR techniques presumably deserve research attention, because photochemical changes linked to plant water status manifest spectral light scattering and absorption changes. Here we estimated the visible and NIR light reflected from the leaf interior and the leaf transmittance of corn (Zea mays L.) leaves having a range of relative water contents. Our results highlight the importance of both scattering effects and effects due to absorption by leaf pigments.
关键词： leaf reflectance,leaf relative water content,RWC,leaf transmittance
更新于2025-09-04 15:30:14
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Improved Vegetation Profiles with GOCI Imagery Using Optimized BRDF Composite
摘要： The purpose of this study was to optimize a composite method for the Geostationary Ocean Color Imager (GOCI), which is the first geostationary ocean color sensor in the world. Before interpreting the sensitivity of each composite with ground measurements, we evaluated the accuracy of bidirectional reflectance distribution function (BRDF) performance by comparing modeled surface reflectance from BRDF simulation with GOCI-measured surface reflectance according to composite period. The root mean square error values for modeled and measured surface reflectance showed reasonable accuracy for all of composite days since each BRDF composite period includes at least seven cloud-free angular sampling for all BRDF performances. Also, GOCI-BRDF-adjusted NDVIs with four different composite periods were compared with field-observation NDVI and we interpreted the sensitivity of temporal crop dynamics of GOCI-BRDF-adjusted NDVIs. The results showed that vegetation index seasonal profiles appeared similar to vegetation growth curves in both field observations from crop scans and GOCI normalized difference vegetation index (NDVI) data. Finally, we showed that a 12-day composite period was optimal in terms of BRDF simulation accuracy, surface coverage, and real-time sensitivity.
关键词： bidirectional reflectance distribution function (BRDF),vegetation profiles,Geostationary Ocean Color Imager (GOCI),composite period,normalized difference vegetation index (NDVI)
更新于2025-09-04 15:30:14
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The effect of TiO <sub/>2</sub> nanopigment on the optical properties of polyester fabric in UV–VIS–NIR regions
摘要： The particle size parameter is a key factor that affects radiative properties of nano-pigments, and consequently, pigments of the same type but different sizes represent different spectral performance. Therefore, current study dealt with a systematic experimental investigation on the effect of TiO2 pigmented coatings on spectral reflectance and color performance of white and colored polyester fabrics in UV, VIS, and NIR region of electromagnetic spectrum, with a special emphasis on VIS region. In order to accomplish this target, polyester fabrics were coated with TiO2 nanopigment with various concentrations and different diameters, and their reflectance spectra were measured using spectrophotometric method. Two-way analysis of variance (ANOVA) was utilized to investigate the significance of the effect of TiO2 nanopigment on the color performance of coated fabrics. According to experimental observations, an organized color shift appears in color coordinate of fabrics coated with TiO2 nanopigment of various sizes. Moreover, although TiO2 nanopigment with 35 nm diameter has the most significant impact on short wavelength region (UV region), the effect of pigment with 250 nm diameter is more noticeable on NIR region as long wavelength region.
关键词： nanopigment,polyester fabric,reflectance spectra,optical property,titanium dioxide
更新于2025-09-04 15:30:14
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Performance evaluation of the SIMBIO-SYS Stereo Imaging Channel on board BepiColombo/ESA spacecraft
摘要： The Stereo Imaging Channel (STC) is one of the channels of the Spectrometer and Imagers for MPO BepiColombo Integrated Observatory SYStem (SIMBIO-SYS) onboard the ESA BepiColombo mission to Mercury. STC is a double wide-angle camera designed to image each portion of the Mercury surface from two different lines of sights, whose main aim is to provide panchromatic stereo-image pairs required to generate the Digital Terrain Model (DTM) reconstruction. In addition, selected surface areas will be acquired in color. This work presents the expected STC on-ground and in-flight performance describing the preliminary evaluation of some key parameters: the optical performance, the on-ground resolution and detector response, the achievable Signal to Noise Ratio (SNR) for different integration times and observation strategies and the global coverage of panchromatic filters during the entire scientific phase. The estimation of the SNR has been made using the STC radiometric model with Hapke reflectance model for Mercury surface and the SPICE toolkit software. The SPICE toolkit software with kernel for BepiColombo mission has been used also for the estimation of the on-ground pixel dimension and the global coverage all over the mission.
关键词： Mercury,Reflectance model,SIMBIO-SYS,STC,SNR,Global coverage
更新于2025-09-04 15:30:14
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Rembrandt's <i>An Old Man in Military Costume</i> : Combining hyperspectral and MA-XRF imaging to understand how two paintings were painted on a single panel
摘要： Over the past several decades the painting An Old Man in Military Costume by Rembrandt Harmensz van Rijn (ca. 1630–31; J. Paul Getty Museum, 78.PB.246) has been the subject of a number of investigations carried out in order to better visualize a second painting beneath the surface figure. The underlying image – the head and shoulders of a man wearing a cloak – is oriented 180 degrees from the upper image and appears to be fairly complete. Scanning macro x-ray fluorescence (XRF) spectroscopy reveals the face is painted with lead white and a mercury-(likely vermilion), and the cloak is painted with a copper-containing pigment. Following the revelation and digital color reconstruction of the underlying figure, a number of questions still remained. Here, through the use of infrared reflectance imaging spectroscopy (i.e., hyperspectral imaging) and macro-XRF imaging spectroscopy, together with cross-sections taken from targeted areas, the sequence of painting in both compositions was explored. Of particular interest was the discovery of evidence of multiple attempts to situate the lower figure, and the subsequent application of a blocking-out layer over the lower figure before the artist rotated the panel and executed the upper figure. In addition, examination of the placement of the two images on the panel adds to our understanding of the subtle complexities of Rembrandt’s working process.
关键词： re-use of painting supports,Early Rembrandt,infrared reflectance imaging spectroscopy,X-ray fluorescence imaging spectroscopy
更新于2025-09-04 15:30:14
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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 - The Use of a Quadcopter-Mounted Hyper-Spectral Spectrometer for Examining Reflectance in Scottish Coastal Waters
摘要： Remote sensing of the marine coastal environment is useful for obtaining information about processes occurring within it. Monitoring has traditionally been carried out in situ, before investment increased in remote techniques such as manned planes and satellites. This paper proposes the use of remotely piloted aircraft systems (RPAS) as an alternative platform, with an aim of increasing the spectral, spatial and temporal resolution of data whilst reducing the associated costs and risks. A custom-built ‘spectro-copter’ system, comprising of an integrated dual field-of-view, miniaturised, hyper-spectral spectrometer aboard a purpose-built quadcopter is presented, developed at the Scottish Association for Marine Science (SAMS), Oban. This has been produced with a view to investigating reflectance from Scottish coastal waters, which can give inferences as to the concentrations of various constituents present [1, 2]. Initial test flights show the ‘spectro-copter’ system is capable of flights of ~20 minutes, sufficient for meaningful data collection, despite late adjustments incurring increased weight and an associated reduction in efficiency. Early results demonstrate that the setup is capable of discerning differences in R at a high spectral resolution. Further work is ongoing in order to assess the capacity for establishing this equipment as a routine technique for the monitoring of coastal harmful algal blooms (HAB), which currently relies upon physical sampling in combination with satellites. HAB events are noted to be increasing in severity and frequency [3, 4], with knock-on health and economic impacts, particularly for the rising aquaculture industry in Scottish coastal waters [5]. Therefore advancement of an alternative, affordable technique would be extremely beneficial.
关键词： spectrometer,Scottish coastal waters,reflectance,remote-sensing,quadcopter,remotely piloted aircraft system,hyper-spectral
更新于2025-09-04 15:30:14