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针对HJ-1A/B卫星CCD数据,建立适合于厦门海域的叶绿素a浓度反演模型,将为持续监测该海域的赤潮提供时间序列的叶绿素a浓度数据。基于2013年7月31日厦门海域水体实测光谱与叶绿素a浓度同步测量数据,及HJ\|1B卫星CCD2光谱响应函数,对各波段遥感反射率与叶绿素a浓度的相关性进行比较,证实蓝、绿波段比值与叶绿素a浓度相关性最高。对OC3模型在内的5种模型的反演结果和实测叶绿素a浓度做相关性分析,发现各模型相关系数均达到0.7以上。利用2013年7月30日实测数据对同期厦门海域HJ-1B卫星CCD2数据叶绿素a浓度反演结果进行精度验证,结果表明本地化的10指数模型在反演叶绿素a浓度动态范围较大的区域具有更高的精度。 相似文献
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基于Landsat 8 OLI遥感影像的天山北坡草地地上生物量估算 总被引:1,自引:0,他引:1
《遥感技术与应用》2017,(6)
利用Landsat 8OLI遥感数据获得NDVI、RVI、DVI、EVI、GNDVI和SAVI等6种常用植被指数,同时结合研究区草地地面实测数据,再根据坡向将研究区划分为阴坡和阳坡两类,利用统计分析方法分别建立紫泥泉牧场阴坡和阳坡的草原生物量遥感估算模型,并进行生物量空间反演和验证。相关分析结果表明:所选植被指数与牧场生物量显著相关,依据坡向分类后数据与未分类数据相关性存在较大差异,其中NDVI相关性最高,EVI相关性最低;紫泥泉草场生物量最优反演模型为基于SAVI的二次多项式模型,精度达80%。利用该模型反演得到2015年紫泥泉牧场草原平均鲜草产草量为113g/m2,折合干草产草量41.85g/m2。研究表明:坡向是影响生物量分布变化的重要因素;利用遥感数据、地面实测生物量数据并结合研究区阴阳坡地形特征,提出的生物量估算模型精度较高,可为该牧区草原生物量合理估算和草地放牧管理提供科学依据。 相似文献
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地形校正是提高复杂地形区地表参数遥感定量化反演精度的重要手段。当前广泛应用的遥感叶面积指数产品(Leaf Area Index, LAI)多具有一定的地形误差,减少地形影响、提升其产品精度有着非常重要的意义。以我国江西省千烟洲地区为研究区域,利用地面实测LAI数据、LandsatTM数据和高程数据等,基于高程标准差和GLOBMAP LAI产品值的关系,建立面向叶面积指数产品的地形校正模型,利用这一模型对GLOBMAP LAI产品进行地形校正。结果表明:校正后的LAI与地面实测数据更为接近,LAI产品与地面测量值的RMSE由2.11下降到2.04;校正后LAI产品的标准差由2.08下降至1.69,LAI产品的地形误差得到了较好的改正。该方法较好地完成了LAI产品的地形校正,进一步提高了产品精度,具有一定的实用价值。 相似文献
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介绍了利用交互式数据语言(Interactive Data Language,IDL)开发TM/ETM遥感影像大气与地形校正模型的详细过程,以2000年4月30日密云ETM影像为例,对大气与地形校正方法的有效性和实用性进行了验证。结果表明,该方法有效地消除了大气与地形影响,提高了地表反射率等地表参数的反演精度和数据质量,为进一步开展定量遥感研究提供了数据质量保障。 相似文献
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应用Landsat TM影像估算渤海叶绿素a和总悬浮物浓度 总被引:4,自引:0,他引:4
利用23个实测样点的渤海叶绿素a和总悬浮物浓度数据及同步Landsat TM影像数据,分别分析了Landsat TM离水辐射亮度对渤海叶绿素a和总悬浮物浓度的敏感性,选择合适的波段,通过回归分析构建了基于Landsat TM离水辐射亮度的渤海叶绿素a和总悬浮物浓度反演模型。结果表明,TM1、TM2和TM3波段对叶绿素a的敏感性较高,以TM4/TM1和TM3/TM2的对数为自变量,以叶绿素a浓度的对数为因变量的线性估算模型可以有效反演渤海叶绿素a浓度,决定系数R2达到0.97;TM3波段对悬浮物的敏感性最高,以TM2、TM3和TM3/TM2为自变量,以总悬浮物浓度的以10为底的对数为因变量的多元线性模型获得的结果最佳,决定系数R2达到0.91。 相似文献
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F. Wang L. Han H.‐T. Kung R. B. Van Arsdale 《International journal of remote sensing》2013,34(23):5269-5283
Water quality in Reelfoot Lake, Tennessee, was investigated in the field over 15 years ago. However, the spatial variations of water quality were not studied. The remote sensing technique has been proved a powerful tool in mapping spatial distributions of some water quality parameters such as chlorophyll‐a concentration. Additionally, different regression methods and various independent variables have been used to establish relationships between water quality parameters and spectral reflectance. The results from this study indicate that Landsat TM2 and TM3, as a set of independent variables in multivariate regression analysis, are good predictors of water quality in Reelfoot Lake. TM2 is positively correlated to water quality, and TM3 is negatively correlated to water quality. Poor water quality, or a high algae load, results in a high reflectance measured by TM2 and a low reflectance measured by TM3. Maps of spatial distribution of Secchi disk depth, turbidity, chlorophyll‐a, and total suspended solids present apparent spatial variations of water quality in the lake. 相似文献
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以我国云南省西双版纳的热带森林为例,分别对栎类林、其它阔叶林、其它硬阔叶林的生物量与其对应的Landsat TM数据及其派生数据、气象数据和地形数据进行了相关性分析。首先,利用森林资源连续清查的林业固定样地数据,通过各树种组的各器官生物量估算模型计算出各样地的森林植被的生物量。然后,根据样地的坐标来建立样地GIS数据库。其次,将同期的遥感影像、气象数据和地形数据与GIS数据进行配准,并从遥感影像中产生出一系列的派生数据。最后,在此基础上,分别对栎类林、其它阔叶林、其它硬阔叶林的样地生物量与其遥感数据和派生数据、气象数据和地形数据进行相关性分析。研究表明,栎类林的生物量与TM1、TM2、TM3、TM4、TM5、TM7、缨帽变换的亮度、绿度、湿度、VI3、DVI、PC1和PVI在0.05的水平上显著,而与其它因子在这个水平上相关都不够显著。其它阔叶林的生物量与降雨量在0.05的水平上显著,而与其它因子在这个水平上相关都不够显著。其它硬阔叶林的生物量与降雨量在0.05的水平上显著,而与其它因子在这个水平上,其相关都不够显著。 相似文献
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M. F. Ramli N. K. Tripathi N. Yusof H. Z. M. Shafri Z. Ali Rahman 《International journal of remote sensing》2013,34(23):6277-6300
Remote sensing has proved to be a useful tool in lineament identification and mapping. This study demonstrates the use of multispectral Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM?+) satellite data obtained over two acquisition dates in 1990 and 2002 for lineament interpretation in a Malaysian tropical environment. A digital elevation model (DEM) was generated to improve the interpretation. We found that most of the major orientations in the field station could be successfully detected from the remotely sensed imagery. The results from the study show that the remote sensing technique is capable of extracting lineament trends in an inaccessible tropical forest. 相似文献
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河流精确提取在水资源调查、利用、变化检测及大型水利设施建设评估等方面具有非常重要的意义.通常的河流信息提取方法受影像中云、冰雪、山体阴影、大型湖泊等的干扰较大,大范围的适用性有限.以Landsat卫星遥感数据为数据源,在归一化差异水指数(NDWI)计算的基础上,首次提出采用高斯归一化水体指数(GNDWI)提取河流水体的模型,使得指数能够更大程度上保证河流提取的连续性,并通过DEM的辅助实现了其他干扰信息的去除.通过对伊犁河试验区河流信息提取的实验结果表明,该方法除了能够实现对复杂多样的河流水体信息进行自动提取外,还可有效去除阴影等信息的混淆,并能够达到较高的河流提取精度. 相似文献
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Detection limits of coral reef bleaching by satellite remote sensing: Simulation and data analysis 总被引:5,自引:0,他引:5
Monitoring of coral reef bleaching has hitherto been based on regional-scale, in situ data. Larger-scale trends, however, must be determined using satellite-based observations. Using both a radiative transfer simulation and an analysis of multitemporal Landsat TM images, the ability of satellite remote sensing to detect and monitor coral reef bleaching is examined. The radiative transfer simulation indicates that the blue and green bands of Landsat TM can detect bleaching if at least 23% of the coral surface in a pixel has been bleached, assuming a Landsat TM pixel with a resolution of 30×30 m on shallow (less than 3 m deep) reef flats at Ishigaki Island, Japan. Assuming an area with an initial coral coverage of 100% and in which all corals became completely bleached, the bleaching could be detected at a depth of up to 17 m. The difference in reflectance of shallow sand and corals is compared by examining multitemporal Landsat TM images at Ishigaki Island, after normalizing for variations in atmospheric conditions, incident light, water depth, and the sensor's reaction to the radiance received. After the normalization, a severe bleaching event when 25-55% of coral coverage was bleached was detected, but a slight bleaching event when 15% of coral coverage was bleached was not detected. The simulation and data analysis agreed well with each other, and identified reliable limits for satellite remote sensing for detecting coral reef bleaching. Sensitivity analysis on solar zenith angle, aerosol (visibility) and water quality (Chl a concentration) quantified the effect of these factors on bleaching detection, and thus served as general guidelines for detecting coral reef bleaching. Spatial misregistration resulted in a high degree of uncertainty in the detection of changes at the edges of coral patches mainly because of the low (∼30 m) spatial resolution of Landsat TM, indicating that detection of coral reef bleaching by Landsat TM is limited to extremely severe cases on a large homogeneous coral patch and shallow water depths. Satellite remote sensing of coral reef bleaching should be encouraged, however, because the development and deployment of advanced satellite sensors with high spatial resolution continue to progress. 相似文献
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R. N. Fraser 《International journal of remote sensing》2013,34(15):3011-3016
This study shows robust correlation of multispectral reflectance data (from Landsat Thematic Mapper) with turbidity among 21 lakes in Nebraska, USA, sampled in June, 1994. Mean lake reflectance percentages ranged from 5-12 (TM1), 4-18 (TM2), 2-12 (TM3) and 1-5 (TM4). Turbidity ranged from 2.7-82.3 nephelometric turbidity units. Correlations were highly significant (r 0.68; P 0.001) between each of the TM bands and turbidity. Linear models were useful for measurement among lakes in the region, despite potential bottom effects or variation in turbidity components due to a range of water quality. 相似文献