共查询到20条相似文献，搜索用时 140 毫秒
1.
2.
利用遗传算法优化神经网络实现混合像元组分参数的反演 总被引：1，自引：1，他引：0
《遥感学报》2000,4(Z1):31-37
采用热红外多波段遥感数据反演陆面温度(LST),由于波段间信息高度相关,以及难以直接反演混合像元组分温度,使得LST的反演精度和应用价值都受到很大的限制.在建立非同温混合像元热辐射方向性模型基础上指出,热红外多角度遥感提供了反演组分温度的可能性,但是,由于该模型是采用蒙特卡洛方法模拟而建立起来的数值概念模型,采用一般反演方法很难同时提取所有参数信息.为了有效获取各参数信息,使用神经网络模型.由于待反演参数中,组分温度、土壤比辐射率和叶面积指数(LAI)都是多角度辐射亮度的非线性函数,然而,使用经典的误差后传(BP)算法容易陷入局部最优解区域;虽然遗传算法(GA)可以搜索到全局最优解,但在微机上实现算法速度太慢,因此,采用GA训练神经网络,得到网络权重,然后再以GA训练得到的权重作为BP算法的初始权重,继续训练神经网络,直到获得满意结果.这样既可以发挥BP算法快速寻优的特点,又能得到网络权重的最优组合.数值模拟的结果表明,基于非同温混合像元热辐射方向性模型,采用GA优化的神经网络模型反演多维参数效果比较理想. 相似文献
3.
地物波谱数据辅助的SPOT影像模拟真彩色方法研究 总被引：1，自引：0，他引：1
提出一种新的高分辨率遥感影像真彩色模拟方法。该方法从遥感成像光谱角度,依据地物波谱特性,采用光谱角匹配模型(SAM),首先计算出地物在绿(G)、红(R)、近红外(NIR)以及短波红外(SWIR)波段的整体和局部波谱向量角;然后根据角度距离构建最小距离隶属函数,查找对应地物波谱库中最为相似的地物波谱;最后对此条地物波谱曲线积分计算出该像素点在蓝波段的反射率。实验表明,该方法模拟出的SPOT真彩色影像在视觉效果和空间信息上优于传统的方法。 相似文献
4.
资源一号02C卫星多光谱数据没有蓝色波段,给制作真彩色影像带来了一定困难。本文针对02C卫星多光谱波段的特点,分析了常用线性模拟蓝波段影像方法,选取多景不同时相的、覆盖山地或平地的真实数据进行加权法和平均值法的对比试验,定性与定量分析后的结果表明：基于加权法生成蓝波段的真彩色模拟结果,无论是从整体色调方面,还是从典型地类的颜色方面,均优于基于平均值法生成蓝波段的真彩色模拟结果,可进一步深入研究后进行规模化应用。 相似文献
5.
6.
基于神经网络方法的极化雷达地表参数反演 总被引：6，自引：1，他引：6
人工神经网络（Artificial Neural Network)是一个由独立处理单元以一定拓扑结构高度连接而成的并行分布式信息处理结构，适于解决各种非线性问题，积分方程（Integrated Equation Model)单散射模型可模拟各种地表参数条件下裸露地表后向散射系数，以IEM为基础生成训练数据，用L波段的C波段SIR-CHH，VV极化单散射后向散射系数数据为神经网络输入，通过后向反馈（BP）神经网络模型可同时反演得到裸露地表条件下地表介电常数，地表相关长度和均方根高度等地表参数。 相似文献
7.
SPOT 5卫星影像在广东省土地资源动态监测中的应用 总被引：4，自引：1，他引：4
介绍了在土地资源监测管理中,利用SPOT 5卫星影像进行正射纠正、全色波段与多光谱数据融合、模拟自然彩色的工艺流程。 相似文献
8.
本文主要探讨了SPOT5卫星遥感影像在1：1万基础测绘中的应用。本文围绕实际生产,重点阐述了卫星遥感影像高精度正射纠正技术、真彩色影像融合处理技术以及大范围影像批量分幅方法,并对不同控制点布设方案制作的卫星遥感正射影像图进行了精度分析。 相似文献
9.
福建省多丘陵、山地,植被覆盖度高,若采用直接真彩色合成或整幅波段加权后真彩色合成效果都不佳,尤其是植被区部分,可以利用植被指数对植被区单独进行波段加权处理后再进行真彩色合成,从而达到理想的效果。最后通过对ALOS和QB数据的试验,分别采用定性和定量比较方法,认为该方法效果最好,并且具有很好的实用性和可操作性。 相似文献
10.
11.
12.
A study on crop discrimination was carried out using simulated IRS 1C LISS-III data produced using visible (to simulate B2, B3) and NIR (to simulate B4) channels from SPOT and middle infrared (MIR) channel (to simulate B5) from TM over a previously investigated test site, characterized by multiple crops and small fields, in Sabarkantha district (Gujarat). The separability amongst dominant kharif season crops, namely, cotton, groundnut, maize, pigeonpea, between crops and various natural vegetation classes was investigated using Jeffries-Matusita (JM) distance, a pair-wise inter-class separability measure. The study highlighted the capability of simulated LISS-III data to be useful in identifying and labelling small fields and the 4-band data set (B2345, i.e., simulated LISS-III) to significantly improve the separability amongst various crops and vegetation over two 3-band sets (B234, equivalent to SPOT)and B345. 相似文献
13.
Integrating multiple images with artificial neural networks (ANN) improves classification accuracy. ANN performance is sensitive to training datasets. Complexity and errors compound when merging multiple data, pointing to needs for new techniques. Kohonen's self-organizing mapping (KSOM) neural network was adapted as an automated data selector (ADS) to replace manual training data processes. The multilayer perceptron (MLP) network was then trained using automatically extracted datasets and used for classification. Two hypotheses were tested: ADS adapted from the KSOM network provides adequate and reliable training datasets, improving MLP classification performance; and fusion of Landsat thematic mapper (TM) and SPOT images using the modified ANN approach increases accuracy. ADS adapted from the KSOM network improved training data quality and increased classification accuracy and efficiency. Fusion of compatible multiple data can improve performance if appropriate training datasets are collected. This proved to be a viable classification scheme particularly where acquiring sufficient and reliable training datasets is difficult. 相似文献
14.
《International Journal of Digital Earth》2013,6(5):351-372
This study compares the spectral sensitivity of remotely sensed satellite images, used for the detection of archaeological remains. This comparison was based on the relative spectral response (RSR) Filters of each sensor. Spectral signatures profiles were obtained using the GER-1500 field spectroradiometer under clear sky conditions for eight different targets. These field spectral signature curves were simulated to ALOS, ASTER, IKONOS, Landsat 7-ETM+, Landsat 4-TM, Landsat 5-TM and SPOT 5. Red and near infrared (NIR) bandwidth reflectance were re-calculated to each one of these sensors using appropriate RSR Filters. Moreover, the normalised difference vegetation index (NDVI) and simple ratio (SR) vegetation profiles were analysed in order to evaluate their sensitivity to sensors spectral filters. The results have shown that IKONOS RSR filters can better distinguish buried archaeological remains as a result of difference in healthy and stress vegetation (approximately 1–8% difference in reflectance of the red and NIR band and nearly 0.07 to the NDVI profile). In comparison, all the other sensors showed similar results and sensitivities. This difference of IKONOS sensor might be a result of its spectral characteristics (bandwidths and RSR filters) since they are different from the rest of sensors compared in this study. 相似文献
15.
基于多进制小波变换的遥感影像融合 总被引：7，自引：0，他引：7
首先介绍了遥感影像融合的理论和方法 ,然后在讨论多进制小波理论的基础上 ,提出了一种基于特征的多进制小波变换的影像融合算法 ,该算法根据待融合影像分辨率之比确定采用多进制小波 ,从而最大限度的利用了待融合影像的信息 ,防止影像信息的丢失。通过对具体影像的实验 ,证明融合后的影像最大限度地保留了待融合影像的光谱信息 ,同时提高了待融合影像的清晰度和空间分辨率。文中给出了SPOT全色影像与SPOT多光谱波段影像、SPOT全色影像与TM影像的融合结果 ,并与其他方法进行了比较 ,证明了本方法的优越性和自适应能力 相似文献
16.
利用卫星遥感数据制作复杂地形环境的植被图面临的最主要问题是精度，单纯对遥感数据（ＴＭ或ＳＰＯＩ）进行监督或非监督分类的精度低于５０％。本文选择美国亚利桑那州ＳａｎｔａＣａｔａｌｉｎａ山脉的ＰｕｓｃｈＲｉｄｇｅ作为研究区，分析地理信息系统模型在改善植被分类精度中的作用。结果表明，通过结合辅助数据和应用地理信息系统模型，其精度可以从３７．４１％提高到７１．６７％（ＳＰＯＴ数据，非监督分类），或从５０．０７％提高到６１．５０％（ＴＭ数据，监督分类）。同时表明用ＳＰＯＴ数据进行山区植被制图的效果好于ＴＭ数据。 相似文献
17.
Barnaby Clark Juha Suomalainen Petri Pellikka 《International Journal of Applied Earth Observation and Geoinformation》2011
SPOT satellites have been imaging Earth's surface since SPOT 1 was launched in 1986. It is argued that absolute atmospheric correction is a prerequisite for quantitative remote sensing. Areas where land cover changes are occurring rapidly are also often areas most lacking in situ data which would allow full use of radiative transfer models for reflectance factor retrieval (RFR). Consequently, this study details the proposed historical empirical line method (HELM) for RFR from multi-temporal SPOT imagery. HELM is designed for use in landscape level studies in circumstances where no detailed overpass concurrent atmospheric or meteorological data are available, but where there is field access to the research site(s) and a goniometer or spectrometer is available. SPOT data are complicated by the ±27° off-nadir cross track viewing. Calibration to nadir only surface reflectance factor (ρs) is denoted as HELM-1, whilst calibration to ρs modelling imagery illumination and view geometries is termed HELM-2. Comparisons of field measured ρs with those derived from HELM corrected SPOT imagery, covering Helsinki, Finland, and Taita Hills, Kenya, indicated HELM-1 RFR absolute accuracy was ±0.02ρs in the visible and near infrared (VIS/NIR) bands and ±0.03ρs in the shortwave infrared (SWIR), whilst HELM-2 performance was ±0.03ρs in the VIS/NIR and ±0.04ρs in the SWIR. This represented band specific relative errors of 10–15%. HELM-1 and HELM-2 RFR were significantly better than at-satellite reflectance (ρSAT), indicating HELM was effective in reducing atmospheric effects. However, neither HELM approach reduced variability in mean ρs between multi-temporal images, compared to ρSAT. HELM-1 calibration error is dependent on surface characteristics and scene illumination and view geometry. Based on multiangular ρs measurements of vegetation-free ground targets, calibration error was negligible in the forward scattering direction, even at maximum off-nadir view. However, error exceeds 0.02ρs where off-nadir viewing was ≥20° in the backscattering direction within ±55° azimuth of the principal plane. Overall, HELM-1 results were commensurate with an identified VIS/NIR 0.02ρs accuracy benchmark. HELM thus increases applicability of SPOT data to quantitative remote sensing studies. 相似文献
18.
植被冠层辐射散射信号中蕴含了丰富的植被信息,通过构建植被冠层辐射散射模型,可以实现植被结构等生物物理参数的遥感定量反演。迄今为止,可见光/近红外、热红外、微波波段均已发展了大量的模型,这些模型在参数反演方面各具优势,但不同波段的模型又有其自身的局限性。跨波段的联合模拟可以实现模型间的优势互补,进而提高地表参数的反演精度,近年来已有学者专注于可见光/近红外与热红外模型,热红外与微波模型,主被动微波模型,以及可见光/近红外与微波模型的联合模拟和协同反演,但多是两两联合,且主要是基于经验模型或解析模型。基于3维场景的植被冠层辐射散射特性模拟模型可以细致刻画不同组分的结构和空间分布特征,对于由植被结构引起的多次散射和组分比例变化的考虑具有优势。本文主要介绍了3维模拟模型在可见光/近红外、热红外和微波波段,以及跨波段联合模拟方面的研究进展,从模型机理、场景统一、以及组分理化参数的统一的角度,探讨了构建多波段3维模拟系统的可行性,展望了多波段3维模拟模型的发展趋势。 相似文献
19.
This paper describes results from a detailed study of circular anomalies—related to outcrops of granitic domes over the western part of the Armorican Massif—using SPOT, Landsat TM, Seasat, and composite imagery in conjunction with aerial photographs. Two types of features have been distinguished: (1) simple and circular, related to small granitic bodies or to hidden domes, which correspond with concentric networks of fractures formed during the cooling of the granite, and (2) complex and composite of the onion skin type, related to the larger plutonic domes. This type of feature could also be related to the concentric cooling networks but would more probably correspond to the magmatic foliation planes. Semi-circular features of the “half-moon” type, derived from these described structures, are located on the periphery of plutonic domes. These could correspond to preliminary intrusions cross cut by the major structures. From the lineament maps and based on the relationship between regional foliation fracturing networks and circular features, the following networks can be distinguished: (1) radial networks centered on plutonic diapirs, which seem to be contemporary with the granitic intrusions; (2) transverse networks that pass around or across circular features, creating fan-shaped forms and which are late with respect to the granitic intrusions; (3) post-tectonic fracturing networks that cross all previously described structures; and (4) a network, parallel to the regional foliation N070, which crosses or twists the circular features. This system documents the syntectonic pattern of the granites. Translated by Judit Ozoray, Chicoutimi, Quebec from: “Structures circulaires et réseaux de fractures en pays granitique. Analyse de données SPOT, Landsat TM et Seasat sur le Massif armoricain,” Bull. Soc. géol. France, 1993, Vol. 164, No. 2, pp. 199-214, with permission of the Société Gèologique de France (please cite original paper). 相似文献
20.
陆地卫星TM图像含有丰富的光谱信息,SPOT全色波段图像数据分辨率较高,因此,如何将这两种图像数据有效地结合起来,在遥感应用领域中显得越来越重要。本文研究了SPOT和TM图像数据的数字复合方法。结果表明,复合后的图像提高了分辨率,增加了光谱信息。 相似文献