基于HJ卫星IRS遥感数据的农作物秸秆火点提取模式研究   总被引：5，自引：0，他引：5  

王玲  田庆久  包颖 《地理科学》2011,31(6):661-667

根据农作物收割前后的HJ-1B 卫星红外相机(IRS)遥感数据特征,提出农作物秸秆焚烧火点提取模式:利用IRS波段3(3.78 μm)与波段4(11.36 μm)结合两种经典火点探测算法首先提取出所有类型的地面火点;再利用收割前后的IRS波段2(1.72 μm)与波段1(0.9 μm)建立农作物秸秆地判定依据,从而从所有类型的地面火点中识别出秸秆火点。结合10月6日、10月21日的HJ-1B IRS影像,对10月21日江苏省农作物收割时期的秸秆火点进行提取实验,并与对应的MODIS探测结果进行相关分析,相关系数R²为0.685,验证了研究方法的合理性。  相似文献   

基于环境小卫星CCD影像的水体提取指数法比较   总被引：1，自引：0，他引：1  

范登科  李明  贺少帅 《地理与地理信息科学》2012,28(2):14-19

针对湖北省大东湖水网水环境遥感监测需求,开展基于环境小卫星CCD影像的内陆湖库水体提取指数方法研究。以常见的3种水体识别指数为模型,参照使用TM、MODIS等典型传感器进行水体提取的波段选择方式,通过对环境小卫星CCD影像4个波段地物光谱信息的变化趋势分析,发现各波段对水体目标的区分能力;使用指数模型和相应阈值分别计算获得水体特征图像,并以目视判读结合精度评价指标的方式对提取结果进行对比分析。实验结果表明,归一化差异综合水体指数的目视判别效果最好,且具有水陆区分度高和误识别率低的特点,适用于解决水体目标快速提取问题。  相似文献   

不同核函数RVM的冰凌检测能力比较     

王春光  徐琪  陈刚  赵根庄 《地理空间信息》2012,(2):67-69,75

利用HJ-1A/1B卫星CCD数据进行黄河凌汛监测,提出了利用相关向量机的检测冰凌,并对比了不同核函数的冰凌检测效果。实验结果显示利用RVM和HJ-1A/1B卫星CCD数据能有效提取出黄河冰凌范围,RBF核函数的稳定性和精度要高于改进型RBF核函数,但改进型RBF核函数的相关向量的个数要明显少于RBF核函数,因此测试速度要高于RBF核函数。  相似文献   

基于6S模型的山区环境星影像大气校正研究     

韩杰  杨磊库  李家国  孟庆岩  李慧娜 《测绘信息与工程》2011,(5):4-7

针对山区地形复杂,高程变化较大的特点,利用6S辐射传输模型建立查找表,结合研究区DEM对影像进行了大气校正。试验结果表明,校正后的影像清晰度、对比度提高了,消除了大气对NDVI的负面影响。  相似文献   

Fusion of HJ1B and ALOS PALSAR data for land cover classification using machine learning methods     

《International Journal of Applied Earth Observation and Geoinformation》2016

Image classification from remote sensing is becoming increasingly urgent for monitoring environmental changes. Exploring effective algorithms to increase classification accuracy is critical. This paper explores the use of multispectral HJ1B and ALOS (Advanced Land Observing Satellite) PALSAR L-band (Phased Array type L-band Synthetic Aperture Radar) for land cover classification using learning-based algorithms. Pixel-based and object-based image analysis approaches for classifying HJ1B data and the HJ1B and ALOS/PALSAR fused-images were compared using two machine learning algorithms, support vector machine (SVM) and random forest (RF), to test which algorithm can achieve the best classification accuracy in arid and semiarid regions. The overall accuracies of the pixel-based (Fused data: 79.0%; HJ1B data: 81.46%) and object-based classifications (Fused data: 80.0%; HJ1B data: 76.9%) were relatively close when using the SVM classifier. The pixel-based classification achieved a high overall accuracy (85.5%) using the RF algorithm for classifying the fused data, whereas the RF classifier using the object-based image analysis produced a lower overall accuracy (70.2%). The study demonstrates that the pixel-based classification utilized fewer variables and performed relatively better than the object-based classification using HJ1B imagery and the fused data. Generally, the integration of the HJ1B and ALOS/PALSAR imagery can improve the overall accuracy of 5.7% using the pixel-based image analysis and RF classifier.  相似文献   

Land-cover impacts on streamflow: a change-detection modelling approach that incorporates parameter uncertainty     

Jan Seibert  Jeffrey J. McDonnell 《水文科学杂志》2013,58(3):316-332

Abstract

The effect of land-use or land-cover change on stream runoff dynamics is not fully understood. In many parts of the world, forest management is the major land-cover change agent. While the paired catchment approach has been the primary methodology used to quantify such effects, it is only possible for small headwater catchments where there is uniformity in precipitation inputs and catchment characteristics between the treatment and control catchments. This paper presents a model-based change-detection approach that includes model and parameter uncertainty as an alternative to the traditional paired-catchment method for larger catchments. We use the HBV model and data from the HJ Andrews Experimental Forest in Oregon, USA, to develop and test the approach on two small (<1 km²) headwater catchments (a 100% clear-cut and a control) and then apply the technique to the larger 62 km² Lookout catchment. Three different approaches are used to detect changes in stream peak flows using: (a) calibration for a period before (or after) change and simulation of runoff that would have been observed without land-cover changes (reconstruction of runoff series); (b) comparison of calibrated parameter values for periods before and after a land-cover change; and (c) comparison of runoff predicted with parameter sets calibrated for periods before and after a land-cover change. Our proof-of-concept change detection modelling showed that peak flows increased in the clear-cut headwater catchment, relative to the headwater control catchment, and several parameter values in the model changed after the clear-cutting. Some minor changes were also detected in the control, illustrating the problem of false detections. For the larger Lookout catchment, moderately increased peak flows were detected. Monte Carlo techniques used to quantify parameter uncertainty and compute confidence intervals in model results and parameter ranges showed rather wide distributions of model simulations. While this makes change detection more difficult, it also demonstrated the need to explicitly consider parameter uncertainty in the modelling approach to obtain reliable results.

Citation Seibert, J. & McDonnell, J. J. (2010) Land-cover impacts on streamflow: a change-detection modelling approach that incorporates parameter uncertainty. Hydrol. Sci. J. 55(3), 316–332.  相似文献   

江苏近岸海域HJ CCD影像悬浮泥沙遥感反演     

王林  杨建洪  李冠男  陈艳拢  孟庆辉 《海洋科学》2016,40(2):77-83

基于2012~2014年期间江苏近岸海域实测遥感反射率、悬浮泥沙浓度及HJ CCD数据,建立该海域HJ CCD影像悬浮泥沙遥感反演模型。通过研究水体实测反射光谱特征,确定对悬浮泥沙浓度变化的敏感波段,并与悬浮泥沙浓度进行函数拟合分析。结果表明:将HJ CCD Band3的等效遥感反射率、HJ CCD Band3与Band2等效遥感反射率的比值分别作为敏感因子,并采用对数函数模拟低值区、指数函数模拟高值区获得的叠加模型表现最为突出。通过卫星应用发现,第2、3波段比值模型的遥感反演结果与实际情况相符,可有效削弱大气校正、表观反射率到遥感反射率的转换方法以及HJ CCD辐射分辨率较低等一系列问题的干扰,为江苏近岸海域HJ CCD悬浮泥沙遥感反演的最优模型。  相似文献