نتایج جستجو برای: داده های landsat

تعداد نتایج: 527839  

Journal: :Data Science Journal 2007
Christopher J. Rusanowski

People believe what they can see. The Poles exist as a frozen dream to most people. The International Polar Year wants to break the ice (so to speak), open up the Poles to the general public, support current polar research, and encourage new research projects. The IPY officially begins in March, 2007. As part of this effort, the U.S. Geological Survey (USGS) and the British Antarctic Survey (BA...

2006
P Boccardo E Borgogno Mondino F Perez P Claps

To evaluate accuracy of low resolution vegetation mapping for hydrological purposes, a comparative study of NDVI images derived from MODIS and Landsat 7 ETM+ data has been done. Main goal is to understand how effective MODIS images can be for vegetation characterization on large areas, as compared to the Landsat 7 ETM+ ones. In this paper a methodology is proposed with the aim of measuring the ...

2013
Douglas A. Stow John E. Estes

The major conclusions reached in this research effort are: 1) Landsat derived land cover classification data are, at present, a marginally accurate data source for county-level resource management requirements; and 2) the accuracy of standard product National Cartographic Information Center (NCIC) Digital Terrain Tape data appear to be questionable, again with respect to the information require...

2005
Lars Eklundh Martin Sjöström

* Corresponding author. Abstract – The semi-arid Sahel zone of Africa has suffered several periods of severe drought since about 1950. We have analyzed AVHRR Normalized Difference Vegetation Index (NDVI) over the Sahel for the period 1982-2002, and found extensive areas of increasing NDVI. To verify these changes we have analyzed Landsat TM and ETM+ scenes from 1984-1986 and 1999-2001 for areas...

2015
Jody C. Vogeler Zhiqiang Yang Warren B. Cohen

a r t i c l e i n f o Post-fire snags provide important resources for cavity nesting communities as well as being subject to timber removal through salvage logging practices. Tools that can characterize their distributions along with other features important as wildlife habitat, such as woody shrub cover, would be useful for research and management purposes. Three dimensional lidar data and Lan...

2005
Ya-Qiu Jin Guangzhen Cao

A hybrid algorithm of the BP-ANN/GA (Back Propagation Artificial Neural Network and Genetic Algorithm) is developed to optimize the initial weights and make fast convergence of the BP-ANN. This algorithm is applied to data fusion of Landsat ETM+ and ERS-2 SAR for classification of the urban terrain surfaces. An example of the Shanghai Pudong area using both the Landsat ETM+ and ERS-2 SAR image ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز 1390

در این پایان نامه پس از مطالعه روش های موجود در زمینه های طبقه بندی بدون ناظر، روش های تلفیق تصاویر نور حساس و چندطیفی و روش های بهینه سازی از جمله الگوریتم های ژنتیک و آموزش-یادگیری، روشی جهت بهبود کیفیت تصاویر سنجش از دور با استفاده از بهینه کردن ترکیب روشهای موجک با حفره و ihs ارائه می دهد و سپس جهت طبقه بندی تصاویر از این روش کمک می گیرد. نتایج بدست آمده از اعمال الگوریتم ها بر روی 4 داده ت...

Journal: :Fact sheet / 2022

First posted June 14, 2022 For additional information, contact: Program Coordinator, National Land Imaging U.S. Geological Survey 12201 Sunrise Valley Drive Reston, VA 20192Contact Pubs Warehouse Scenic Arkansas certainly lives up to its nickname, “The Natural State.” The Ozark Plateau and Ouachita Mountains boast stunning views, vast resources, recreation. Hardwood pine forests cover one-half ...

Journal: :Fact sheet / 2021

First posted August 3, 2021 Revised February 17, 2023 For additional information, contact: Program Coordinator, National Land Imaging U.S. Geological Survey12201 Sunrise Valley Drive Reston, VA 20192Contact Pubs Warehouse The Green Mountain State of Vermont is known for its vast swaths deciduous forest, patches evergreen, and the Mountains that run through center.Valuable insight into forests l...

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