塔里木河荒漠植被光谱可分性模拟   总被引：3，自引：2，他引：1  

赵金  陈曦  古丽·加帕尔  马忠国  常存 《中国沙漠》2009,29(2):270-278

以塔里木河典型植被为研究对象,分析胡杨、芦苇叶片及柽柳冠层的可分性,并计算背景的影响。首先用ASD光谱仪测新鲜叶片光谱,找出光谱特征点;然后模拟EO-1高光谱数据和TM多光谱数据;最后植被与土壤光谱按比例混合,分析背景的影响。以上三步分别计算植被指数（VI）。结果显示:叶片光谱特征位置430 nm、670 nm、750 nm附近,黄边斜率和红外平台平均高度,1 080~1 280 nm、1 430~1 650 nm能够区分塔里木河流域3个主要植被类型。模拟的EO-1波谱保持了控制波形的10个特征,TM 只有绿反射峰和红吸收谷、近红外1个反射峰3个特征,大部分特征都消失了。植被指数显示(R680-R500)/R750、(R680-R550)/R705、R1430+\:+R1650、D712/D688能够区分3类,且指数值差异较大,为绿峰、红谷和近红外波峰的组合;模拟的EO-1数据(R680-R500)/R750、(R680-R550)/R705、R1430+\:+R1650能分别区分植被,TM多波谱数据不能有效区分植被。  相似文献   

南极温度的时空特征及其与我国夏季天气的关系   总被引：3，自引：0，他引：3       下载免费PDF全文

卞林根  陆龙骅  张永萍 《极地研究》1989,1(3):8-17

本文利用南极地区20个站1958—1983年逐年逐月温度资料和同期南方涛动指数、北半球高度场资料及我国大范围温度和降水资料,对南极地区冷暖变化规律及其与北半球大气环流和我国夏季降水的关系进行了初步分析。发现南极地区的温度和南方涛动都存在准3年振荡,我国华北地区的夏季温度与前期和同期南极大陆的温度存在显著的遥相关。 当南极大陆夏季温度偏高时,翌年我国华北地区夏季降水往往偏多,东北地区夏季温度偏低,反之亦然。  相似文献   

“祝融号”火星车多光谱相机岩矿类型识别的地面验证研究   总被引：1，自引：0，他引：1  

谢涓  闫凯  康志忠  徐箫剑  薛彬  杨建峰  陶金有 《遥感学报》2021,25(7):1385-1399

中国首个自主火星探测任务“天问一号”探测器于2020-07成功发射,其搭载的中国首台火星车“祝融号”将在着陆火星后开展巡视探测,获取中国火星探测的原始科学数据。识别火星表面岩矿类型对于了解火星的大气变化、环境状态、地质演化以及生物宜居性等具有重要意义。本研究利用“祝融号”火星车搭载的多光谱相机载荷鉴定件（8个波段）在地球环境下拍摄并获取了18种火星表面岩矿的多光谱影像数据。基于该数据所开展的火星岩矿类型的识别研究可为未来基于“祝融号”多光谱相机数据进行火星表面岩矿的原位识别提供指导。本文所采用的基于多光谱影像波段运算和彩色图像HSV颜色特征直方图的岩矿识别方法,可从多光谱特征和颜色特征两个层面来识别不同类型的岩矿。所使用的多光谱影像数据是在太阳高度角约60°、拍摄高度1.8 m、拍摄角度约37°的条件下采集所得。在该实验条件下,两种识别方法共提取出12种岩矿的识别指标。基于多光谱影像波段运算可以区分出在8个特定波段下具有突出光谱特征的岩矿类型,而基于图像HSV颜色特征可区分出颜色特征分布较为集中的岩矿类型。同时,研究发现拍摄角度不同会对岩矿的识别效果产生不可忽略的影响。  相似文献   

基于无人机遥感的黄海绿潮搁浅生物量估算     

尚伟涛  高志强  姜晓鹏  田信鹏  郭少方 《海洋科学》2021,45(10):11-19

浒苔在近岸搁浅后会破坏海岸景观,干扰水上运动,给滨海旅游业造成严重影响。本文使用无人机搭载的多光谱和可见光传感器对山东半岛的海阳、乳山和文登的三个海滩搁浅的浒苔进行航拍监测,并结合地物光谱测量数据,分别选择归一化植被指数（NDVI）、差值植被指数（DVI）和虚拟基线高度浮藻指数（VB-FAH）对海滩搁浅浒苔与岸边植被及非植被（海水、沙滩）进行识别评估,并分别估算了三个研究区搁浅浒苔的生物量。研究结果表明：NDVI可以识别植被和非植被,但无法区分潮间带上部和潮间带下部分布的浒苔;DVI和VB-FAH对植被和非植被的区分度不高,但对不同分布的搁浅浒苔具有一定的区分度,其中,DVI对潮间带上部和潮间带下部分布浒苔的识别能力优于VB-FAH。因此,通过对岸边植被进行腌膜,利用DVI构建海滩搁浅浒苔生物量估算模型,实现了海滩搁浅浒苔生物量的估算。海阳、乳山和文登三个海滩搁浅浒苔的生物量分别为1 468 t、745 t和5 034 t,本文提出的方法可以为搁浅浒苔的清理和资源合理分配提供技术支持。  相似文献   

Three-Dimensional Geographically Weighted Inverse Regression (3GWR) Model for Satellite Derived Bathymetry Using Sentinel-2 Observations     

Andrzej Chybicki 《Marine Geodesy》2018,41(1):1-23

Current trends of development of satellite derived bathymetry (SDB) models rely on applying calibration techniques including analytical approaches, neuro-fuzzy systems, regression optimization and others. In most of the cases, the SDB models are calibrated and verified for test sites, that provide favorable conditions for the remote derivation of bathymetry such as high water clarity, homogenous bottom type, low amount of sediment in the water and other factors. In this paper, a novel 3-dimensional geographical weighted regression (3GWR) SDB technique is presented, it binds together methods already presented in other studies, the geographically weighted local regression (GWR) model, with depth dependent inverse optimization. The proposed SDB model was calibrated and verified on a relatively difficult test site of the South Baltic near-shore areas with the use of multispectral observations acquired by a recently launched Sentinel-2 satellite observation system. By conducted experiments, it was shown that the proposed SDB model is capable of obtaining satisfactory results of RMSE ranging from 0.88 to 1.23[m] depending on the observation and can derive bathymetry for depths up to 12m. It was also shown, that the proposed approach may be used operationally, for instance, in the continuous assessment of temporal bathymetry changes, for areas important in the context of ensuring local maritime safety.  相似文献   

南京沿江湿地高光谱与多光谱遥感分类对比分析     

高原  赵波  蔡悦 《测绘与空间地理信息》2016,(8):57-60

随着遥感技术的发展,以及对湿地分类研究的不断深入,如何提高分类精度成为一大研究方向。分类方法、影像数据源、影像的特征提取都影响着分类结果的精度。目前,利用影像数据进行湿地分类,精度难以提高主要是受影像像源的制约,其中,不同湿地类型波谱特性之间的混淆是制约精度提高的直接原因。高光谱(Hyperspectral)遥感是20世纪末对地观测系统中较重要的技术突破之一,随着定量化研究的发展,高光谱遥感技术以其光谱分辨率较高的特点受到国内外广泛关注,并在资源、环境、城市、生态等领域得到了广泛应用。本文比较了湿地分类中hyperion的数据与landset TM数据的分类精度。在进行分类时,使用监督分类的方法(SVM)对南京新济州、新生州、江心洲的湿地地物类型进行分类。结果表明,在训练样本合适的前提下,用高光谱数据进行分类可以得到更高的分类精度。  相似文献   

Quantification of the Total Suspended Matter Concentration around the Sea Breaking Zone from In Situ Measurements and Terra/Aster Data     

《Marine Georesources & Geotechnology》2007,25(2):67-80

Remote sensing techniques can be used to quantify the total suspended matter concentration (TSM). The main objective of this study is the quantification of the TSM concentration around the sea breaking zone for a particular area of the Portuguese coast, near Aveiro city. The methodology used was based on in situ measurements and on multispectral satellite image from TERRA/ASTER. In situ experimental techniques were used to determine a relationship between the TSM concentration and the seawater reflectance. Empirical relationships were established between TSM concentration and the equivalent reflectance values for TERRA/ASTER at visible and near infrared bands computed from the experimental data. The reflectance values had a very high correlation with the TSM concentration in the wavelength between 500 and 900 nm. The ASTER image was calibrated, atmospherically and geometric corrected. Equations of linear, polynomial, logarithmic, power and exponential models were applied. The best results were found with the linear and polynomial models, with a determination factor higher than 0.95. However, the differences in the TSM concentration calculated for the three bands indicate that we should not use the information of a single band to obtain the TSM concentration.  相似文献   

Remote sensing and GIS analyses of the Strangways impact structure,Northern Territory     

H. Zumsprekel  L. Bischoff 《Australian Journal of Earth Sciences》2013,60(4-5):621-630

Remote sensing and GIS techniques play a substantial role for the identification of possible terrestrial impact structures, for mapping target-rock lithologies and deciphering the structural style of known craters. In this case study the lithological and structural characteristics of the highly eroded Proterozoic Strangways impact crater in the Northern Territory have been analysed on the basis of Landsat Enhanced Thematic Mapper satellite imagery, topographical data and airborne geophysical data. Regarding Landsat data, the calculation of basic statistical parameters and the optimum index factor has been found useful for a pre-selection of informative band combinations. By means of the analysis of multisensoral data, the distribution of crystalline basement rocks, siliciclastic target rocks of the Roper Group as well as post-impact deposits and deeper seated Proterozoic dykes can be detected. The original crater dimensions of the Strangways structure are carefully estimated at 26?–?29 km by combining the remote sensing data with the distribution of shatter cones localised in the field. The remote sensing/GIS approach of a geological interpretation based on multisensoral sources and combined fieldwork data can be successfully applied to other impact structures on earth, as well.  相似文献   

面向应用需求的星载多光谱相机指标设置探讨     

张振华  甘甫平  王军 《国土资源遥感》2015,(2):1-7

卫星研制和应用相互脱节是卫星数据质量无法有效满足应用需求的重要原因之一,如果不进行调整,将制约国产卫星数据的推广应用。在影响卫星数据质量的诸多因素中,其载荷相机的指标设置是核心和关键,因其决定了所获取数据的可应用范围及效益。在对国内外卫星载荷指标设置系统调研分析的基础上,根据国内用户对数据的使用情况,以地质矿产应用需求为主,兼顾土地、环保、农业、林业以及减灾等行业应用需求,就用户关心的相机谱段范围、空间分辨率、图像幅宽及重访周期等可见光/近红外多光谱相机基本指标设置提出了建议,旨在为相机的研制提供应用支撑。  相似文献   

Spatial database updating using active contours for multispectral images: application with Landsat 7     

S. Jodouin  L. Bentabet  D. Ziou  J. Vaillancourt  C. Armenakis 《ISPRS Journal of Photogrammetry and Remote Sensing》2003,57(5-6):346

This paper presents a fully automated approach for area detection and delineation based on multispectral images and features from a topographic database. The vectors residing in the database are refined using active contours (snakes) according to updated information provided by the multispectral images. The conventional methods of defining the external energy guiding the deformation of the snake based on: (1) statistical measures; or (2) gradient-based boundary finding is often corrupted by poor image quality. Here a method to integrate the two approaches is proposed using an estimation of the maximum a posteriori (MAP) segmentation in an effort to form a unified approach that is robust to noise and poor edges. We further propose to improve the accuracy of the resulting boundary location and update of the snake topology. A number of experiments are performed on both synthetic and LANDSAT 7 images to evaluate the approach.  相似文献