共查询到18条相似文献，搜索用时 93 毫秒
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本文探讨利用新一代微卫星遥感数据CHRIS/PROBA定量反演三峡坝区叶绿素(Chl)浓度的方法。首先对CHRIS/PROBA高光谱影像进行去条带、几何校正、辐射校正、大气校正等预处理,得到水体像元的遥感反射率;然后结合三峡坝区水质,分析了悬浮物对叶绿素浓度反演的影响,采用半经验回归方法建立了叶绿素浓度反演算法;最后在对算法验证的基础上,将模型应用到经过一系列预处理的影像中,得到三峡坝区叶绿素浓度的遥感反演结果,并对反演结果进行了分析。分析表明,CHRIS/PROBA影像在三峡坝区水质的遥感监测中是可用的,且反演结果精度较高。 相似文献
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航天高光谱遥感器CHRIS的水体图像大气校正 总被引：2，自引：0，他引：2
CHRIS(Compact High Resolution Imaging Spectrometer)是欧空局于2001年10月发射的PROBA-1卫星上搭载的探索性高光谱遥感器,它具备高空间分辨率、多角度观测、高光谱成像等特点,为水质遥感监测提供不可多得的数据源。基于卫星遥感图像定量监测水质,一个关键步骤就是进行精确的大气校正,提取水面反射率。相比陆地遥感图像,水面反射率是弱信号,对大气校正的要求更高。6S(Second Simulation of SatelliteSignal in the Solar Spectrum)和MODTRAN(MOderate resolution TRANsmittance code)是两种常用的大气辐射传输模型。本文选取基于6S的REMS(Remote Sensing Environmental Monitoring System)和基于MODT-RAN的ACORN(Atmospheric CORrection Now)两种大气校正软件,对太湖梅梁湾的三景不同成像角度CHRIS图像进行大气校正,将大气校正后的图像水体反射率与地面同步实测水体反射率进行比较分析。结果表明,经过大气校正的CHRIS图像得到的水面反射率与实测反射率波形十分地接近,在全部波长范围内的相关系数达到90%。分析实测的水体反射率角度特征,发现图像的角度特征更明显。三个观测角度下反射率之间的各差值都呈现出在绿光波段较大,在红光和近红外波段偏小的特点,这和实测结果相符。ACORN校正后的图像的角度特征更好地与实测结果吻合。 相似文献
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赵传章 《测绘与空间地理信息》2016,(1)
由于多角度卫星的快速发展,多角度的应用也随之而来。由于多角度观测卫星可同时提供多角度观测数据,提供立体像对,从而为提取影像高程信息成为了可能。我们在制作DSM、DEM等数字3D产品时,都需要对多角度影像进行高精度的配准,并且配准的精度会影响到以上应用的效果,因此,对多角度影像进行配准研究非常必要。本文针对CHRIS/PROBA卫星影像,对目前多角度影像的配准方法进行探讨。 相似文献
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地形校正是遥感影像定量化应用环节之一,以往的地形校正研究多是针对一景影像中很小的局部影像块来进行处理研究的,对整景大场景影像进行地形校正的研究尚不多。基于此,本文利用高分一号的宽视场相机拍摄的16 m分辨率的遥感影像,研究了大场景下地形校正方法,对C校正模型进行了改进,在C校正模型中加入了反射角的影响,并且验证了改进模型的合理性;最后对改进的模型与余弦校正模型、传统的C校正模型的处理结果进行了比较。通过分析,利用改进的模型,影像的标准差普遍变小,影像校正后的阴阳坡亮度值趋于一致的趋势更明显。试验结果表明,对大场景、非星下点成像的遥感影像利用改进模型进行地形校正效果明显增强。 相似文献
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影像目视判读常会遇到山脊与沟谷的凹凸感与现实相反的反立体现象。消除反立体现象,能有效提高非专业人员对遥感影像的正确使用。立足于反立体现象的成因,本文采用地形正规化模型来校正影像的反立体现象,推导出Lambertian、Cosine-Civco、c校正、b校正这4种地形正规化模型的反立体校正式;对这4种地形正规化模型的反立体校正效果进行了对比,并且与其他5种校正法也进行了对比。通过3个实验区的校正发现,这4种地形正规化模型均能校正反立体现象,但校正影像存在色调偏差;Lambertian、Cosine-Civco的反立体校正影像立体感较强,但影像色调改变较大,视觉效果偏差;c校正、b校正的校正影像在视觉效果和定量指标上都比较接近,基本保持地物光谱信息,校正效果相对较好。从定量指标来看,b校正的反立体校正影像的各指标值整体最小,一定程度代表b校正能取得相对较好的反立体校正效果。与其他方法的对比表明,c校正和b校正的反立体校正不局限于波段个数,在有效消除反立体现象的同时,能相对较好的保留地物光谱信息,有利于影像的定量应用。 相似文献
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海岸带地区SPOT-5遥感影像无控制点正射校正方法 总被引：1，自引：0，他引：1
本文利用ENVI遥感软件处理平台,针对海岸带地区影像特点,对传统的SPOT-5遥感影像正射校正流程进行改进,主要有:增加SPOT传感器辐射校正;在影像融合前,使用伪正射校正代替几何校正;利用GDEM数据代替传统的DEM测量数据及野外测点数据;使用Google Earth Bridge功能检验校正结果精度。结果表明:经过改进的无控制点正射校正流程可有效减少人为误操作产生的误差,降低了正射校正的难度,提高了影像处理的效率,拓宽了影像检验的思路。正射校正影像精度符合研究要求,取得较为满意的结果。 相似文献
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本文基于对传统不变目标区域校正法的改进,选择4期辐射定标参考影像对DMSP-OLS影像进行了饱和校正与时间序列连续性校正。通过阈值法去除了NPP-VIIRS影像的背景噪声及异常值,利用对数变换压缩了其灯光辐射值的动态范围,使其亮度分布更接近于DMSP-OLS数据。利用BiDoseResp函数模型对NPP-VIIRS影像进行了一致性校正,获得了1992-2019年长时间序列夜间灯光影像。从定性、定量及校正影像与社会经济参量的相关性方面对校正结果进行了精度验证。结果表明,改进后的校正方法改善了DMSP-OLS影像饱和严重的现象,使其获得了长时间序列纵向可比性。BiDoseResp函数模型可以很好地拟合DMSP-OLS和对数变换后的NPP-VIIRS之间的回归。校正后的长时间序列灯光影像数据与社会经济参量高度契合。校正结果对推广长时间序列夜间灯光影像的广泛应用、深化长时间序列科学问题的研究具有重要价值。 相似文献
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遥感影像中的不均匀现象是遥感影像处理中要解决的一个重要问题。现有的遥感影像不均匀性校正方法通常都是针对亮度不均匀进行处理的,对于反差不均匀性校正并没有好的解决方案。针对遥感影像中同时存在亮度、反差不均匀的情况,提出了一种基于LRM均值-方差规定化的不均匀校正算法。该方法以LRM影像分块处理为基础,结合影像均值-方差规定化原理,对遥感影像进行处理。实验证明,该方法不仅能够校正亮度不均匀现象,而且对于反差不均匀现象也有很好地校正作用,能够达到整体影像的亮度、反差一致性,获得更加清晰的影像。 相似文献
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为探讨不同大气校正模型对高分六号(GF-6)WFV影像清晰度的提升,利用主客观相结合的方法对大气校正后的影像清晰度进行评价。结果表明:1)不同大气校正模型对影像清晰度提升的效果不同。从基于地理视觉要素的主观评价来看,大气校正后的GF-6 WFV影像纹理特征更为明显,清晰度得以提升。2)基于影像特征的定量评价结果表明,不同的大气校正模型对GF-6 WFV影像清晰度提升程度不同,快速大气校正对影像提升效果最为明显。3)从基于色彩保真度的定量评价结果可知,不同大气校正结果对不同地物反射率影响较为明显,FLAASH大气校正结果更适合于植被遥感应用研究,快速大气校正模型的适用范围更广。 相似文献
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Computer simulation models have seldom been applied for estimating the structural and biophysical variables of forest canopy. In this study, an approach for the estimation of leaf area index (LAI) using the information contained in hyperspectral, multi-angle images and the inversion of a computer simulation model are explored. For this purpose, L-systems combined with forest growth model ZELIG were applied to render 3-D forest architectural scenarios. The Radiosity-graphics combined model (RGM) was used to estimate forest LAI from the Compact High-Resolution Imaging Spectrometer/Project for On-Board Autonomy (CHRIS/PROBA) data. LAI inversion was performed using the look-up table (LUT) method. The estimated LAI was evaluated against in situ LAI measurement and compared against the LAI predictions from CHRIS data obtained using the Li-Strahler geometric-optical canopy reflectance model (GOMS). The results indicated that the method used in this study can be efficient strategy to estimate LAI by RGM model inversion. 相似文献
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选取江西省余干县的一景CHRIS/PROBA影像5个观测角度(±55°、0°和±36°)的反射率,在CHRIS数据处理后得到的NDVI基础上得到HDVI,并与野外实测的草地、灌木、针叶林、针阔林和阔叶林的VFC建立相关性分析,以及对于模型拟合度的决定系数R2的影响因素进行分析。结果表明,在±55°下,针阔林的多项式拟合度最高,植被类型模型的拟合度均值也最高。其次是灌木拟合度较高。最差的是针叶林指数模型,植被类型的整体拟合度最不理想。在±36°下,针阔林多项式拟合度最高,植被类型的整体拟合度也最高,其次是阔叶林拟合度较高。最差的是针叶林的指数模型,植被类型的整体拟合度也是最不理想的。 相似文献
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First results from the PROBA/CHRIS hyperspectral/multiangular satellite system over land and water targets 总被引：1，自引：0，他引：1
The Project for On-Board Autonomy (PROBA) platform developed by the European Space Agency was launched on October 22, 2001. The instrument payload includes the Compact High Resolution Imaging Spectrometer (CHRIS). The coupled system provides high spatial resolution hyperspectral/multiangular data, which represents a new-generation source of information for Earth observation purposes. The first results obtained from the preprocessing (noise removal and geometric/atmospheric correction) of two different datasets, collected over agricultural crops and inland waters, are presented in this letter. In situ measurements are used to assess the quality of the data and to validate the processing algorithms. The capabilities of this new kind of information for an improved analysis of the surface properties are shown, focusing on the advantages that the coupling between the spectral and the angular domains may have in future Earth observation systems. 相似文献
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《地理信息系统科学与遥感》2013,50(4):541-565
In this study, we examine seasonal aspects and the potential of multi-angle CHRIS/PROBA data, acquired at two different dates, to improve forest classification. The test site is a typical peat swamp landscape located in Central Kalimantan, Indonesia. We focus on eight specific land use/cover categories from a single view angle and from a multi-angular perspective. We show that: (1) reflectance changes from the end of the monsoon to the beginning of the dry season in the visible were small and slightly positive for the forestry classes, whereas slightly negative for grassland classes; (2) reflectance increases according to the successional stages for a given angle and were higher in the beginning of the dry season; (3) reflectance values increase in the near-infrared with decreasing leaf area index (LAI); and (4) classification results using a multi-angular approach were statistically better at a 5% level of significance from a single view approach on both selected dates, showing that anisotropy information can improve differentiation between peatland landscape classes. 相似文献
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Petr Lukeš Miina Rautiainen Pauline Stenberg Zbyněk Malenovský 《International Journal of Applied Earth Observation and Geoinformation》2011
The spectral invariants theory presents an alternative approach for modeling canopy scattering in remote sensing applications. The theory is particularly appealing in the case of coniferous forests, which typically display grouped structures and require computationally intensive calculation to account for the geometric arrangement of their canopies. However, the validity of the spectral invariants theory should be tested with empirical data sets from different vegetation types. In this paper, we evaluate a method to retrieve two canopy spectral invariants, the recollision probability and the escape factor, for a coniferous forest using imaging spectroscopy data from multiangular CHRIS PROBA and NADIR-view AISA Eagle sensors. Our results indicated that in coniferous canopies the spectral invariants theory performs well in the near infrared spectral range. In the visible range, on the other hand, the spectral invariants theory may not be useful. Secondly, our study suggested that retrieval of the escape factor could be used as a new method to describe the BRDF of a canopy. 相似文献
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辐射归一化旨在减小不同时相遥感影像间因获取条件不一致而导致的非地表辐射变化的差异,是土地覆盖变化监测的重要前提条件。本文根据高光谱图像上同类地物的谱形及数值的相似性,利用光谱角距离(SAD)和欧氏距离(ED)双重判定选取不变特征点,提出了一种基于光谱角—欧氏距离的辐射归一化方法。在评价指标中除了常用的均方根误差和相对偏差,更增加了高光谱特色的衡量光谱保真性指标:皮尔森系数、光谱扭曲程度。利用高光谱遥感CHRIS图像对本文提出方法进行验证,并与基于多元变化检测(MAD)的辐射归一化方法比较。结果表明,本文方法不仅在辐射特性上优于基于多元变化检测(MAD)的方法,而且具有保持光谱特性的优势,具有较好的应用前景。 相似文献
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Lênio Soares Galvão Flávio Jorge PonzoniVeraldo Liesenberg João Roberto dos Santos 《International Journal of Applied Earth Observation and Geoinformation》2009
CHRIS/PROBA data collected in the Brazilian Amazônia in 4 view angles (−36°, nadir, +36°, +55°) and 62 bands (410–1000 nm range) were evaluated for the discrimination between primary forest and 3 stages of secondary succession after deforestation: initial (SS1; <5 years), intermediate (SS2; 5–15 years) and advanced (SS3; >15 years). Single view angle and multiangular approaches (nadir plus anisotropic information derived from reflectance ratios between view angles) were tested for discrimination. Both approaches used principal components analysis (PCA) applied to pixel spectra representative of each class in order to reduce data dimensionality at each dataset, to enhance separability between the classes, and to provide input variables for multiple discriminant analysis (MDA). The results showed that the off-nadir viewing improved discrimination between the successional stages. Discrimination between SS2 and SS3 was enhanced with PCA at +36° view angle. Primary forest and SS3 presented a more anisotropic behavior than SS2 and SS1, especially in the backward scattering direction (positive view angles) in which great amounts of sunlit canopy components were viewed by the sensor. MDA classification results showed that the multiangular approach produced an overall improvement in the discrimination. From the single (nadir) to the multiangular approach, classification accuracy using a separate set of pixels increased from 83.3% to 98.3% for SS1, 53.3% to 70.0% for SS2, and 58.3% to 76.7% for SS3. The nadir and multiangular classifications were statistically different at a 0.05% level of significance. Kappa statistics increased from 0.63 to 0.82. The results showed that multiangular data can improve the differentiation between primary forest and old stages of natural vegetation regrowth, which have been reported in the literature as the most difficult classes to be mapped in the Amazonian environment. 相似文献