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1.
应用卫星多角度遥感识别被老鼠和昆虫破坏的草地(英文) 总被引：1，自引：0，他引：1
该文研究用ＡＶＨＲＲ数据监测Ｒｕｏｒｇａｉ县大草原被老鼠、昆虫破坏的情况。鼠虫危害区的光谱特征是：ＡＶＨＲＲ数据的可见光波段（０．５８－０．６８μｍ）地面反射率（ＣＨ１）较高，近红外波段（０．７２５－１．１μｍ）的地面反射率（ＣＨ２）较低，红外辐射波段（３．５５－３．９３μｍ）的亮度温度（ＣＨ３）较高；鼠虫危害区的遥感信息特征在雨季７月最为明显；可用比值植被指数ＲＶＩ（ＣＨ２／ＣＨ１）确定鼠虫危害程度；用多角度获得的ＲＶＩ可反映鼠虫危害。结果显示在这方面上，多角度遥感比多波段光谱法能更好地识别老鼠、昆虫破坏的地区。 相似文献
2.
本文利用日本北方岛屿Ｈｏｋｋａｉｄｏ地区的草地、高山农耕和稻田的ＪＥＲＳ－１（Ｌ波段ＳＡＲ）和ＥＲＳ－１（Ｃ波段ＳＡＲ）影像进行了面向农业的ＳＡＲ数据多季节性分析。 相似文献
3.
雪域和表面反照率的精确测量对于推进人们认识全球气候系统非常重要。这是因为大面积雪盖的高反射特性（北半球的冬季，雪可覆盖到４０％的陆地表面）。雪的反射随太阳光线入射角度和观测角度的变化而变化。我们已采用具有不同空间分辨率的可见光传感器来获得雪的参数。目前，从卫星观测器能获得的只是天底观测方向反射数据，因此需要用多角度进行观测来获得雪域的半球反射率。我们建议用包括不同观测角信息和多极化信息的ＰＯＬＤＥＲ数据来研究雪域的方向反射。载于ＡＤＥＯＳ１卫星上的ＰＯＬＤＥＲ已于１９９６年８月成功发射。但目前仍不具备ＰＯＬＤＥＲ数据，我们研究采用的是从可定向的机载分光辐射谱仪获得的ＡＳＡＳ数据。从Ｍｏｎｔａｔａ冰河国家公园采集的数据显示出很强的角度依赖性。初步的结果证实了雪反射的各向异性。对雪盖ＢＲＤＦ认识是以后的发展真实反照率模型的关键。 相似文献
4.
３维矢量结构ＧＩＳ拓扑关系研究３ＤＶＥＣＴＯＲＳＴＲＵＣＴＵＲＥＧＩＳＴＯＰＯＬＯＧＩＣＡＬＲＥＬＡＴＩＯＮＳＨＩＰＲＥＳＥＡＲＣＨ李青元（中国测绘科学研究院,北京,１０００３９）该论文的目的是对３维矢量结构ＧＩＳ（地理信息系统）的拓扑关系进行研究。... 相似文献
5.
全球定位系统（ＧＰＳ）及其在高等级道路勘测中的应用ＧＬＯＢＡＬＰＯＳＩＴＩＯＮＩＮＧＳＹＳＴＥＭ（ＧＰＳ）ＡＮＤＩＴＳＡＰＰＬＩＣＡＴＩＯＮＴＯＨＩＧＨ－ＧＲＡＤＥＲＯＡＤＲＥＣＯＮＮＡＩＳＳＡＮＣＥＳＵＲＶＥＹ姚连璧（同济大学测量与国土信息工程系,... 相似文献
6.
研究利用高光谱成像数据,用数字的方法定量模拟了ＳＯＰＴ－ＨＲＶ,ＣＢＥＲＳ－ＣＣＤ,Ｌａｎｄｓａｔ５－ＴＭ和ＮＯＡＡ１４－ＡＶＨＲＲ类似波段的空中表面反射率及地面光谱反射度图像,并利用这些对上述传感器相应波段的光谱响应,大气影响特性用基于反射率和基于归一化植被指数的方法进行了定量比较分析。 相似文献
7.
将要用来处理来自即将开始运行的ＥＯＳＭＯＤＩＳ和ＭＩＳＲ仪器的ＢＲＤＦ／反照率乘积的反照率反演程序包中的ＢＲＤＦ模型在该文中被用来对来自ＡＶＨＲＲ数据的ＳＡＨＥＬ地区的方向反射数据进行建模。模型被证明能够很好地描述观测到的数据。同时也讨论了核的选择和导出模型的参数所含的信息内容等问题。 相似文献
8.
ＰＯＬＤＥＲ（地球反射极化和方向）仪器在ＢＯＲＥＡＳ实验中曾搭载ＮＡＳＡ的一架Ｃ１３０飞机飞行。在ＢＯＲＥＡＳ的南部地区，ＰＯＬＤＥＲ获取了各种实验场地上的ＢＲＤＦ测量值。森林覆盖地区的大的热点特征，以及十个地区上的镜面反射分量得到了描述。该文通过ＰＯＬＤＥＲ的测量数据，对向常规的光谱特征中加入通过遥感获得的方向性特征后，对各种森林覆盖的分类和区分能力的提高给出了定量化的解。当将方向信息加入常规光谱信息后，采用无监督分类时，类间耦合矩阵的各项显著减小（减小倍数为２－５倍）。这一事实证明了用遥感方向特征可以增强对ＢＯＲＥＡＬ森林覆盖的区分能力。 相似文献
9.
本文在分析ＰＣ ＡＲＣ／ＩＮＦＯ文件存贮结构,数据存贮结构的基础上利用高级编程语言主ＰＣ ＡＲＣＶ／ＩＮＦＯ ＳＭＬ语言进行开发的用户界面,具有操作简单,直观等特点同时大大提高了使用效率。 相似文献
10.
1 地球观测卫星的过去表 1 已停止运行的地球资源遥感卫星卫星所属国家或组织运行时间传感器图像类型波段数分辨率 /ｍＬａｎｄｓａｔ＿1(ＥＲＴＳ＿1) 美国 1972 - 1978ＭＳＳ多光谱 479ＲＢＶ视频 380Ｌａｎｄｓａｔ＿2美国 1975 - 1982 ＭＳＳ多光谱 479ＲＢＶ视频 380ＳＥＡＳＡＴ 美国 1978- 1978ＳＡＲ雷达 12 5Ｌａｎｄｓａｔ＿3美国 1978- 1983ＭＳＳ多光谱 47912 40ＲＢＶ视频 130Ｎｉｍｂｕｓ＿7美国 1978- 1986ＣＺＣＳ多光谱 6 82 5～ 10 0 0ＮＯＡＡ＿6 美国 1979- 1987ＡＶＨＲＲ多光谱 4110 0ＳＰＩＮ＿2俄罗斯 1980 - 199… 相似文献
11.
This letter describes the concept of using delta-K technique on interferometric synthetic aperture radar (InSAR) data for deriving the snow water equivalent (SWE) of dry snow-covered ground by utilizing the presence of scatterers in both datasets. The main scattering contribution from a dry snow cover is from the snow-ground interface. Thus, the interferometric phase of two SAR images, one with no snow and one with dry snow cover, contains information on the SWE. By performing a delta-K processing of the two SAR scenes followed by averaging, an estimation of the SWE can be achieved. The first step in the delta-K InSAR processing is to split the band into two nonoverlapping subfrequency band images. The resulting two subband images then contain two new carrier frequencies with a small delta frequency or delta-K separation. The next step is to multiply the two subband images together to obtain the delta-K image, one for summer and one for winter. Finally, the delta-K interferometric SAR image is generated by multiplying the two delta-K images from summer and winter together. In this letter, experimental results using European Remote sensing Satellite 1 (ERS-1) data from a summer and winter situation show that the delta-K phase can be estimated to a few degrees accuracy for an area of 10/spl times/10 km/sup 2/ corresponding to an SWE accuracy of approximately 100 mm. 相似文献
12.
Praveen K. Thakur Pradeep K. Garg Shiv P. Aggarwal Rahul D. Garg Sneh Mani 《Journal of the Indian Society of Remote Sensing》2013,41(4):933-945
The current study has used Synthetic Aperture Radar (SAR) satellite data to estimate the Snow Cover Area (SCA) in Manali watershed of Beas River in Northwest Himalayas of Himachal Pradesh, India. SAR data used in this study is of Radarsat-2 (RS2) and Environmental Satellite (ENVISAT), Advanced Synthetic Aperture Radar (ASAR). The SAR preprocessing was done with SAR image processing tools for converting raw SAR images into calibrated geo-coded backscatter images. Maps for forest, built area, layover and shadow were created and used for masking snow cover in these areas. The backscattering ratio of wet snow to reference image threshold method with value range from ?2 to ?3 db was used to estimate wet SCA for study area. In this technique, if the threshold is too high (≥-2 db) wet SCA is overestimated and if it is too low (≤-3db), this method underestimates the SCA. The wet SCA is under/over estimated (+6 % to?8 % on average) in late spring season due to the inherent terrain and SAR imaging effects of layover/foreshortening and shadow and also due to the masking of forest areas. Overall, the SCA derived from SAR data matches well when compared with total SCA derived from cloud free optical remote sensing data products, especially during wet season. 相似文献
13.
C-band dual polarization (HH, HV) Synthetic Aperture Radar (SAR) data from Radarsat-2 were used to discriminate and characterize mangrove forests of the Sundarbans. Multi-temporal data acquired during winter and rainy seasons were analysed for the segregation of mangrove forest area. A decision rule based classification involving combination of three-date HH (range −11 to −2 dB) with single-date cross-polarization ratio (2–8) was applied on the datasets for discriminating mangrove forests from other land cover classes. Application of textural measures (entropy and angular second moment) in the aforesaid decision rule based classification produced three broad homogeneous mangrove classes. The area covered by the most homogeneous class increased from January to March and decreased from July to September, and correlated well to the change in the phenological status of the mangroves. Extent of homogeneous areas was more in the eastern region of the Sundarbans than that of the central and western side. Thus, the study revealed that textural measures combined with multi-temporal HH backscatter and single-date cross-polarization ratio in a decision rule classification could be satisfactorily used for characterization of the mangrove forests. 相似文献
14.
基于MODIS影像的内蒙古草原积雪监测 总被引：2，自引：0，他引：2
光学遥感源MODIS具有高光谱分辨率、高时间分辨率、高空间分辨率、全球范围内免费接收等优势,被广泛应用于洪涝、干旱、森林草原火灾、雪灾等自然灾害的动态监测领域。MODIS数据用于内蒙古草原积雪监测,提取积雪信息在国内尚属空白。本文利用MODIS L1B 500m分辨率数据,经过几何校正、去"双眼皮"预处理,根据归一化差分积雪指数(NDSI)算法和综合阈值判别法对内蒙古自治区2008年1月下旬大范围降雪进行积雪信息提取,制作积雪覆盖图。利用内蒙古生态与农业气象中心发布的雪情遥感监测信息验证积雪覆盖图的准确度。验证结果表明,MODIS数据用于大范围积雪监测非常有效。 相似文献
15.
多频率InSAR提取沼泽湿地DEM精度对比分析 总被引：1，自引：1，他引：0
选取3种波长的干涉SAR数据对提取沼泽湿地区域的DEM，并随机从1：10 000地形图中选取111个点数据进行精度验证，最后对比分析了沼泽湿地植被对于不同SAR波长的干涉相干性差异。结果表明：L-band ALOS-1 PALSAR精细模式的HH单视复数数据与1：10 000地形图数据吻合度较好，76.58%的高程值差异在3 m以内，其相干系数比C-band Sentinel-1A IW模式的VV单视复数数据和X-band TerraSAR HH单视复数数据要高；更适合利用雷达干涉测量技术提取沼泽湿地的DEM；不同湿地植被类型的相干系数有较大差异，岛状林和灌草结合的湿地植被分布区相干系数值较大，而浅水沼泽植被区和深水沼泽植被区相对较低。 相似文献
16.
Kátia Kellem da Rosa Cláudio Wilson Mendes Jr. Jorge Arigony-Neto Jefferson Cardia Simões 《国际地球制图》2016,31(9):1032-1043
This work analysed the spatio-temporal variation of snow cover on the Kraków Ice Field, located in the King George Island, Antarctica. High spatial resolution images of COSMO-SkyMed were used in this study. These X-band images are vertically and horizontally co-polarized and their intensity data were converted to amplitude (dB). The COSMO-SkyMed images were classified by a minimum distance algorithm and post-classified based on knowledge of adjacency relationships of snow zones. Hypsometric, slope, aspect and solar radiation maps to support the interpretation of backscatter patterns in the COSMO-SkyMed images. Three radar zones were classified in these images: percolation, slush and wet snow radar zone. Positive surface air temperatures and rainfall events, registered from a meteorological station, lead to increase in wet snow and slush zones. The COSMO-SkyMed images and minimum distance algorithm were adequate to discriminate the snow cover and to assess the supraglacial melting pattern during the ablation season in the study area. 相似文献
17.
利用SVM的全极化、双极化与单极化SAR图像分类性能的比较 总被引：1，自引：0，他引：1
支持向量机(SVM)以其在小训练样本时良好的分类性能,目前已广泛应用于多个领域.本文在极化SAR图像特征提取基础上,将SVM应用于极化SAR图像分类,定性和定量地比较了全极化、双极化和单极化SAR图像的分类性能,分析了不同的极化组合对分类结果的影响,并根据地物极化散射特性分析了分类精度差异的成因.实测极化SAR数据的实验结果表明,全极化数据能获得最好的分类性能,双极化次之,单极化最低,且在某些情况下,双极化与全极化分类性能接近. 相似文献
18.
用星载合成孔径雷达(SAR)立体影像生成DEM的方法研究 总被引：3，自引：0，他引：3
星载SAR成像是一种微波成像,由于微波具有穿透云雾、雨雪等的特点,使得SAR能够不受天气和时间的限制而对地球扫描成像,这使得SAR具有一般光学成像所没有的优点。人们正积极探索把SAR数据用于测绘并来解决一些问题。考虑到卫星在短时间内的运动比较平稳,并且它的相对关系精确度高,本文主要从SAR成像的几何角度和两景影像的相对关系出发,分析了雷达成象的特点,进而探讨了从立体像对上提取DEM的方法,并就具体步骤做了进一步的阐述。 相似文献
19.
Satellite Remote Sensing, with both optical and SAR instruments, can provide distributed observations of snow cover over extended and inaccessible areas. Both instruments are complementary, but there have been limited attempts at combining their measurements. We describe a novel approach to produce monthly maps of dry and wet snow areas through application of data fusion techniques to MODIS fractional snow cover and Sentinel-1 wet snow mask, facilitated by Google Earth Engine. The method is demonstrated in a 55,000 km2 river basin in the Indian Himalayan region over a period of ∼2.5 years, although it can be applied to any areas of the world where Sentinel-1 data are routinely available. The typical underestimation of wet snow area by SAR is corrected using a digital elevation model to estimate the average melting altitude. We also present an empirical model to derive the fractional cover of wet snow from Sentinel-1. Finally, we demonstrate that Sentinel-1 effectively complements MODIS as it highlights a snowmelt phase which occurs with a decrease in snow depth but no/little decrease in snowpack area. Further developments are now needed to incorporate these high resolution observations of snow areas as inputs to hydrological models for better runoff analysis and improved management of water resources and flood risk. 相似文献
20.
利用TM高光谱图像提取青藏高原喀喇昆仑山区现代冰川边界 总被引：19，自引：0，他引：19
采用阈值法、监督分类、非监督分类、谱间关系法对冰川的TM图像进行了分类,证明利用比值图像取阈值是对冰川区图像分类的有效手段。对图像处理的结果进行了分析和解释,并指出了存在的问题。 相似文献