面向对象的农田信息遥感影像分割算法     

苏腾飞  李瑞平 《测绘科学》2016,41(3):49-53

为了提高农业遥感数据处理中多光谱影像分割的精度,文章提出了一种面向农田信息提取的遥感影像分割算法:利用KMeans非监督分类算法和Fisher标准估算多光谱遥感影像中各个波段的权值,并将估算的波段权值应用到光谱合并计算中,能够较好地提高农田区域的分割精度,实现基于全局最优合并的区域生长算法,得到最优化的分割结果;从分割结果中提取基于区域的NDVI信息可以较为快速、准确地区分农田和非农田区域。实验结果说明:该方法的分割精度优于传统的全局最优合并算法和FNEA算法,并对遥感影像中旱田和水田的提取均有较好的效果。  相似文献   

广义马尔可夫随机场及其在多光谱纹理影像分类中的应用   总被引：1，自引：0，他引：1  

赵银娣  张良培  李平湘 《遥感学报》2006,10(1):123-129

在二维马尔可夫随机场模型的基础上，提出顾及波段间的空间相关性，发展了一种适用于多光谱纹理影像分类的广义马尔可夫随机场模型。鉴于广义马尔可夫随机场模型的复杂性，利用最大伪似然法建立了求解模型参数的简化方程式，实现了纹理特征的快速提取。结合提取的纹理特征影像和光谱特征影像，采用概率松弛算法实现影像的分类。实验证明，提出的基于广义马尔可夫随机场的多光谱纹理影像分类算法克服了传统的基于光谱特征的分类算法的局限性，提高了纹理影像的分类精度。  相似文献   

Extraction of altered minerals from Aster remote sensing data in Gongchangling iron deposit of Liaoning,China     

LUAN Yiming  HE Jinxin  DONG Yongsheng  JIANG Tian  XIAO Zhiqiang 《世界地质(英文版)》2022,25(1):16-25

The precision of Aster data is higher than that of Landsat series of multispectral remote sensing data,which can more accurately reveal the distribution of altered minerals.It plays an important role in prospecting,but it is rarely used in areas with complex terrain and high vegetation coverage.Based on this purpose,this study used Aster remote sensing data,and took Gongchangling iron deposit as a case study.It combined the mineral spectrum theory and the basic geologic data of the study area,using the model of principal component analysis(PCA)and color synthesis to extract abnormal altered minerals.The results show that the distribution of identified anomalies is basically consistent with the existing geological data in this study area,which provides a reliable reference for the mineral resources ex-ploration and delineation of mining areas.  相似文献   

Edge enhancement in multispectral satellite images by means of vector operators     

《Geofísica Internacional》2014,53(3):289-308

Edge enhancement is an element of analysis to derive the spatial structure of satellite images. Two methods to extract edges from multispectral satellite images are presented. A multispectral image is modeled as a vector field with a number of dimensions equal to the number of bands in the image. In this model, a pixel is defined as a vector formed by a number of elements equal to the number of bands. Two vector operators are applied to such vector field. In our first method, we extend the definition of the gradient. In this extension, the vector difference of the window central pixel with neighboring pixels is obtained. A multispectral image is then generated where each pixel represents the maximum change in spectral response in the image in any direction. This image is named a multispectral gradient. The other method, considers the generalization of the Laplacian by means of an η-dimensional Fourier transform. This image is named a multispectral Laplacian. The vector operators perform a simultaneous extraction of edge-content in the spectral bands of a multispectral image. Our methods are parameter-free. Our methods work for a multispectral image of any number of bands. Two examples are discussed that involve multispectral satellite images at two scales. We compare our results with widely used edge enhancement procedures. The evaluation of results shows better performance of proposed methods when compared to widely used edge operators.  相似文献   

全色/多光谱融合影像的MVG无参考质量评价     

包科迪  孟祥超  邵枫  叶蒙梦  金康俊  彭振宇 《遥感学报》2022,26(3):568-578

同时具有高空间分辨率和高光谱保真度的全色/多光谱融合影像具有广泛的应用前景.然而,一方面全色/多光谱融合方法通常会产生不同的空间畸变或光谱失真;另一方面,受卫星成像系统限制,无法获取真实高空间分辨率多光谱参考影像,因此,如何在无真实参考影像情况下有效评估融合影像质量具有重要意义.为此,本文提出了一种基于多元高斯模型(M...  相似文献   

多光谱遥感图像的自适应各向异性扩散滤波     

王毅  张良培  李平湘 《遥感学报》2005,9(6):659-666

图像滤波预处理不仅有助于增强图像信噪比和减少类间(intra-c lass)光谱可变性,而且还能够对影像中亮度均匀的区域进行平滑,从而为影像地物识别、分割和分类提供有力的支持。在Pope和Acton提出的两个多光谱图像各向异性扩散滤波模型的基础上,通过各向异性扩散和稳健统计学的联系,建立了基于B iwe ight Estim ator误差模型的扩散系数,同时利用非线性退化技术对梯度阈值的改进,提出了两个基于各向异性扩散方程的非线性滤波方法。提出的方法不仅能够有效地消除传感器随机噪声的影响,而且还能够很好地保持遥感图像上重要的细节边缘和影像质量。实验结果表明,不论是视觉效果还是质量统计分析,提出的扩散模型的性能优于Pope和Acton的各向异性扩散模型,是理想的多光谱图像保边缘滤波方法。  相似文献   

Mapping forest windthrows using high spatial resolution multispectral satellite images     

《International Journal of Applied Earth Observation and Geoinformation》2020

Wind disturbances represent the main source of damage in European forests, affecting them directly (windthrows) or indirectly due to secondary damages (insect outbreaks and forest fires). The assessment of windthrows damages is very important to establish adequate management plans and remote sensing can be very useful for this purpose. Many types of optical remote sensing data are available with different spectral, spatial and temporal resolutions, and many options are possible for data acquisition, i.e. immediately after the event or after a certain time. The objective of this study is to compare the windthrows mapping capabilities of two multispectral satellite constellations (i.e. Sentinel-2 and PlanetScope) characterized by very different spectral, spatial and temporal resolutions, and to evaluate the impact of the acquisition conditions on the mapping results. The analysed area, with an extent of 732 km², is located in the Trentino-South Tyrol region (Italy) which was affected by the Vaia storm on the 27th-30th of October 2018, causing serious forest damages. The change vector analysis technique was used to detect the windthrows. For each data source, two pairs of images were considered: 1) pre- and post- event images acquired as close as possible to the event; 2) pre- and post- event images acquired at optimal conditions, i.e. at similar phenological state and similar illumination conditions. The results obtained with the two satellite constellations are very similar despite their different resolutions. Data acquired in optimal conditions allowed having the best detection rate (accuracy above 80 %), while data acquired just after the event showed many limitations. Improved spatial resolution (PlanetScope data) allows for a better delineation of the borders of the windthrow areas and of the detection of smaller windthrow patches.  相似文献   

基于WOFOST模型与UAV数据的玉米生长后期地上生物量估算     

程志强  蒙继华  纪甫江  汪洋  方慧婷  于丽红 《遥感学报》2020,24(11):1403-1418

地上生物量能够有效反映作物的生长状态，其信息的实时估算对产量预测和农田生产管理都有重要意义。作物生长模型因其详尽的生理生化基础和对生长过程数字化描述能力，成为生物量估算的理想模型。近年来，研究人员利用数据同化算法将时间序列遥感数据同化到作物生长模型中，实现了作物模型由基于气象站的点模拟到区域尺度面模拟的外推，使生物量模拟结果同时具备大范围和机理性两个方面的特点。这一模式下，时间序列的遥感数据质量将对生物量模拟精度产生直接影响，作物生长后期受到光谱饱和的影响，遥感数据的作物冠层信息获取能力会出现明显下降，因此有必要对该阶段遥感数据和作物模型的结合方式进行优化，提升生物量模拟精度。本文针对东北地区春玉米生物量遥感估算存在的问题，提出了利用WOFOST作物模型结合无人机（UAV）遥感数据实现作物生长后期生物量准确估算的新思路。新思路首先利用多光谱遥感数据获取WOFOST模型具备较高空间异质性的土壤速效养分参数以提升模型的空间信息模拟能力，使其能在一定程度上摆脱点尺度模拟的限制。同时，结合集合卡尔曼滤波算法将生长前期无人机（UAV）遥感数据同化到模型中，以缩短模型单独运行时间，减少模型运行过程中的参数误差累积，实现无遥感数据参与下的短期作物生长模拟，并输出生长后期相应的生物量模拟结果。最后，本文利用地面实测数据对新方法的生物量模拟精度进行了评价。结果表明，与全生育期数据同化相比，新方法的生物量估算精度有了明显的提升（全生育期同化：R² = 0.45，RMSE = 4254.30 kg/ha；新方法：R²= 0.86，RMSE = 2216.79 kg/ha）。  相似文献   

Monitoring turbidity from above: Deploying small unoccupied aerial vehicles to image in‐stream turbidity     

Karyn Ehmann  Christa Kelleher  Laura E. Condon 《水文研究》2019,33(6):1013-1021

Small unoccupied aerial systems (sUASs) are increasingly applied to study hydrologic processes and water quality. Here, we evaluate a novel application of sUAS to stream turbidity monitoring, with the goal of extending analyses implemented with satellite remote sensing to enable high resolution, rapid collection of turbidity imagery along smaller waterbodies. To accomplish this, we collected multispectral imagery using two sUAS platforms under a range of environmental conditions along a local creek in Syracuse, NY. In addition, we collected in situ turbidity observations immediately after each flight along several transects along the creek, as well as within a clear plume created by a natural spring entering the main channel of the creek. The in situ turbidity values were compared with the mean and standard deviation of several single‐band and multiband indices extracted along similar transects from the sUAS flights. On the basis of data collected across several flights, we found optical metrics obtained from multispectral imagery correlated well with in situ turbidity measurements. Though many optical metrics yielded strong relationships considering only values within the main channel, values associated with the red band were strongly related to turbidity estimates from the main channel as well as lower turbidity values observed in the spring plume. Although there are still limitations of this approach associated with variable field conditions, results from this proof of concept analysis show that sUASs offer a promising avenue for cost‐effective turbidity monitoring.  相似文献   

利用无人机的多光谱参数预测荔枝叶片养分质量分数     

周慧  苏有勇  王重洋  陈金月  赵晶  姜浩  陈水森  李丹 《热带地理》2019,39(4):562-570

以花芽分化期荔枝为例，分析了荔枝冠层叶片养分质量分数的空间分布差异；选用18种光谱变量，研究了荔枝不同冠层叶片养分质量分数与光谱变量的关系及其对无人机多光谱遥感监测模型的影响。结果表明：荔枝不同冠层叶片的氮、钾质量分数随冠层高度降低而明显提高；冠层中、上层叶片氮质量分数与无人机正射数据计算的类胡萝卜素反射指数（CRI）相关性最高（r＝0.86，p＜0.01）；冠层中、下层叶片钾质量分数与无人机正射数据的光谱变量显著相关，且与标准绿波段（NG）指数的相关程度最高（r＝-0.83，p＜0.01）。荔枝冠层叶片养分质量分数空间变化对基于垂直观测遥感数据建立的叶片养分质量分数估算模型精度有影响，无人机多光谱数据具有估算荔枝叶片氮、钾质量分数变化的潜力，但估算精度与冠层高度有关。  相似文献