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1.
Adrianos Retalis Nicolaos Sifakis 《ISPRS Journal of Photogrammetry and Remote Sensing》2010,65(1):17-25
Low and moderate spatial resolution satellite sensors (such as TOMS, AVHRR, SeaWiFS) have already shown their capability in tracking aerosols at a global scale. Sensors with moderate to high spatial resolution (such as MODIS and MERIS) seem also to be appropriate for aerosol retrieval at a regional scale. We investigated in this study the potential of MERIS-ENVISAT data to resolve the horizontal spatial distribution of aerosols over urban areas, such as the Athens metropolitan area, by using the differential textural analysis (DTA) code. The code was applied to a set of geo-corrected images to retrieve and map aerosol optical thickness (AOT) values relative to a reference image assumed to be clean of pollution with a homogeneous atmosphere. The comparison of satellite retrieved AOT against PM10 data measured at ground level showed a high positive correlation particularly for the AOT values calculated using the 5th MERIS’ spectral band (R2=0.83). These first results suggest that the application of the DTA code on cloud free areas of MERIS images can be used to provide AOT related to air quality in this urban region. The accuracy of retrieved AOT mainly depends on the overall quality, the pollution cleanness and the atmospheric homogeneity of the reference image. 相似文献
2.
Abstract In this paper we process diachronic SPOT satellite images acquired with different viewing angles in order to assess the aerosol optical thickness (AOT) spatial distribution over Brescia. This urban area, located in Northern Italy, is subject to frequent visibility‐reducing smog episodes. AOT was calculated by using the Differential Textural Analysis (DTA) code on a satellite data series consisting by one pollution‐free and various pollution‐loaded SPOT images. The resulting maps showed the horizontal distribution of AOT with a resolution of 500 metres. These maps can be readily integrated with the results obtained by mesoscale modelling, ground measurements, and respond to local scale application requirements. Satellite AOT retrieval compared successfully with available AOT ground‐based measurements and with pollution measurements in the ambient air. In this study the use of diachronic multiangle SPOT imagery allowed us to analyse the effect of the viewing angle variation on AOT retrieval accuracy based on the contrast reduction method. 相似文献
3.
苏南大运河沿线城市热岛现象的卫星遥感分析 总被引：18，自引：2，他引：18
本文利用陆地卫星TM热红外波段的数据对苏南大运河沿线城市苏州、常州、镇江的热环境作了分析,了解各市热岛效应的强度,分布和成因,调查了热岛内部的精细结构。研究表明TM热红外图像能较好地揭示城市下垫面的微细热现象的景观结构,反映温度场的分布,可为城市热环境质量评价和热源调查提供丰富的信息。 相似文献
4.
A. P. Subudhi N. D. Sharma Debajit Mishra 《Journal of the Indian Society of Remote Sensing》1989,17(3):85-99
Visual interpretation of Landsat Thematic Mapper data coupled with ground checking has been used to extract information for urban areas. The emphasis has been given on development of land use/land cover scheme and image interpretation keys for interpretation and delineation purposes using satellite remote sensing data. Lucknow city and its surroundings have been studied to evaluate the usefulness and potentiality of satellite data particularly Landsat Thematic Mapper for urban area studies. This study has demonstrated that remote sensing can provide a valuable tool for urban data acquisition. 相似文献
5.
以2001年7月11日LandsatETM7影像和2009年7月16日TM影像为数据源,基于V-I-S理论模型,采用归一化光谱分解模型提取了乌鲁木齐市区范围内2个时段的植被、土壤、不透水层3个连续地表参数分量。通过对不透水层不同阈值的划分,提取了2时段的乌鲁木齐市城市发展的空间信息,结果较为满意;通过空间叠加计算方式获取了8年来乌鲁木齐市城市化发展的空间信息和主要拓展方向。结果表明,乌鲁木齐城市化发展速度较快,特别是北扩趋势显著。 相似文献
6.
7.
Changes in landscape composition and configuration patterns of Sancaktepe Municipal District in the Asian side of Istanbul Metropolitan City of Turkey were analysed using landscape metrics. Class-level and landscape-level metrics were calculated from the land cover/land use data using Patch Analyst, an extension in the Arc View GIS. The land cover/land use data were derived from classified satellite images of Landsat Thematic Mapper of 2002 and 2009 for Sancaktepe District. There was evidence of increase in agglomeration process of built-up patches as indicated by the increases in mean patch size, decrease in total edge and number of patches between 2002 and 2009. The urban expansion pattern experienced overall was not fragmented but concentrated due to infilling around existing patches. Changes in Area-Weighted Mean Shape Index and Area-Weighted Patch Fractal Dimension Index indicated that the physical shapes within built-up, forest and bareland areas were relatively complex and irregular. A conclusion is made in this study that spatial metrics are useful tools to describe the urban landscape composition and configuration in its various aspects and certain decisions whether to approve a specific development in urban planning could, for example, be based on some measures of urban growth form or pattern in terms of uniformity and irregularity, attributable to the dynamic processes of agglomeration and fragmentation of land cover/land use patches caused by urban expansion. 相似文献
8.
Abstract Landsat Thematic Mapper (TM) data have been used to monitor land cover types and to estimate biophysical parameters. However, studies examining the spatial relationships between land cover change and biophysical parameters are generally lacking. With the integration of remote sensing and Geographic Information Systems (GIS), these relationships can be better explored. The research reported in this paper applies this integrated approach for detecting urban growth and assessing its impact on vegetative greenness in the Zhujiang Delta, China. Multi‐temporal Landsat TM data were utilized to map urban growth and to extract and identify changes in vegetative greenness. GIS analyses were conducted to examine the changing spatial patterns of urban growth and greenness change. Statistical analyses were then used to examine the impact of urban growth on vegetative greenness. The results revealed that there was a notably uneven urban growth pattern in the delta, and urban development had reduced the scaled Normalized Difference Vegetation Index (NDVI) value by 30% in the urbanized area. 相似文献
9.
《International Journal of Digital Earth》2013,6(2):115-142
Abstract On site observation is the most common way of monitoring cultural heritage sites and monuments in Cyprus. However, this procedure that includes data collection, periodical observations, and multivariate risk assessment analysis is difficult to accomplish with the traditional practices and methods since it is time consuming and expensive. Furthermore, many archaeological sites and monuments are located at inaccessible areas, far away from the main road network and urban areas. Satellite remote sensing and Geographical Information Systems (GIS) can successfully confront this problem by providing the scientists with integrated monitoring of the study areas and the unique advantage to store and manipulate a large amount of spatial and attribute data simultaneously. Actually the monitoring and identification of several natural and anthropogenic hazards in the vicinity of the cultural heritage sites in Cyprus, seems to be one of the main priorities of its governmental and municipal authorities. This study aims to integrate both satellite remote sensing techniques and GIS in a multidisciplinary approach, for monitoring anthropogenic and natural hazards with the use of archived and up-to-date multitemporal remotely sensed images in the study area, namely in areas nearby cultural heritage sites and monuments in Cyprus. In this study anthropogenic hazards include urbanisation and extended land use changes in the surroundings of archaeological sites and natural hazards concern seismicity and sea erosion. 相似文献
10.
Sunyurp Park 《地理信息系统科学与遥感》2016,53(5):634-650
Spatiotemporal characteristics and anthropogenic signals of aerosol optical thickness (AOT) distributions over Korea are investigated in this study using AOT time-series data from the Moderate Resolution Imaging Spectroradiometer (MODIS). AOT observations, a quantitative measure of the atmospheric quality, had significant geographical variations during the study period (2000–2010). Comparing metro cities or counties with similar populations, western regions showed higher AOT values than eastern regions. Particular matter with a diameter < 10 µm (PM10), including aeolian dust or yellow dust, is the primary component of atmospheric aerosols, and their transport into the region has shown a strong seasonal pattern with its peak from March to April and lows from July to September. These seasonal dust patterns, however, did not correspond well to temporal AOT records, which typically reached the maximum level in June nationwide. Rather, widespread regional fire events and humidity showed significant correlations with AOT time-series. This correlation rapidly increased as the range of fire occurrence was extended to the west as far as 115°E. The relative humidity also had a significant correlation with AOT during the month of June. In addition to urban emission of anthropogenic aerosols, regional biomass burning and secondary growth of hygroscopic aerosols are considered important contributors to the degradation of the atmospheric environment during the non-Asian Dust season over the Korean Peninsula. 相似文献
11.
Minghong Tan 《地理信息系统科学与遥感》2016,53(4):444-458
Defense Meteorological Satellite Program (DMSP)/Operational Linescan System (OLS) nighttime imagery provides a valuable data source for mapping urban areas. However, the spatial extents of large cities are often overestimated because of the effect of over-glow from nighttime light if a fixed thresholding technique is used. In the work reported here, an inside buffer method was developed to solve this issue. The method is based on the fact that the area overestimated is proportional to the extent of the lit area if a fixed threshold is used to extract urban areas in a region/county. Using this method, the extents of urban areas in North China were extracted and validated by interpretations from Landsat Thematic Mapper images. The results showed that the lit areas had a significant linear relationship with the urban areas for 120 representative cities in North China in 2000, with an R2 value of over 0.95. This demonstrates that the inside buffer method can be used to extract urban areas. The validation results showed that the inside buffer model developed in 2000 can be directly used to extract the extent of urban areas using more recent nighttime light imagery. This is of great value for the timely updating of urban area databases in large regions or countries. 相似文献
12.
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
13.
时间序列遥感影像常用于地表覆盖监测及其变化监测。然而,利用时序遥感数据—尤其是中分辨率遥感数据监测地表覆盖变化,其方法基本是先对多期影像分别进行监督分类然后对比分类结果。由于这种方法需要对每期遥感影像单独选择分类训练样本,而对于历史影像,常常难以获得可靠的样本数据。本文基于遥感数据定量化处理,尝试利用光谱特征扩展方法对时间序列Landsat数据进行分类:首先,结合一种新的大气校正方法和相对辐射归一化方法,对时间序列Landsat数据进行定量化处理,以消除各期影像之间的辐射差异,获得地表反射率数据。然后,论文选择一期易于获得分类训练样本的反射率数据作为"参考影像",并结合样本数据提取不同地表覆盖类型的光谱特征。最后,将"参考影像"中提取的地物光谱特征,扩展到所有时间序列反射率数据进行分类。论文利用青藏高原玛多地区的5景Landsat数据对本文的方法进行了验证,结果显示:基于光谱特征扩展的分类方法,可有效对定量化处理后的Landsat数据进行分类,分类总体精度为88.35%—94.25%,分类结果和传统的单景监督分类结果具有较好的一致性。此外,研究也发现,"参考影像"和待分类图像获取时间的季相差异会影响其分类的精度。 相似文献
14.
Fusion of multispectral and panchromatic Satellite images using the curvelet transform 总被引：18，自引：0，他引：18
Myungjin Choi Rae Young Kim Myeong-Ryong Nam Hong Oh Kim 《Geoscience and Remote Sensing Letters, IEEE》2005,2(2):136-140
A useful technique in various applications of remote sensing involves the fusion of different types of satellite images, namely multispectral (MS) satellite images with a high spectral and low spatial resolution and panchromatic (Pan) satellite image with a low spectral and high spatial resolution. Recent studies show that wavelet-based image fusion provides high-quality spectral content in fused images. However, the results of most wavelet-based methods of image fusion have a spatial resolution that is less than that obtained via the Brovey, intensity-hue-saturation, and principal components analysis methods of image fusion. We introduce an improved method of image fusion which is based on the amelioration de la resolution spatiale par injection de structures (ARSIS) concept using the curvelet transform, because the curvelet transform represents edges better than wavelets. Because edges are fundamental in image representation, enhancing the edges is an effective means of enhancing spatial resolution. Curvelet-based image fusion has been used to merge a Landsat Enhanced Thematic Mapper Plus Pan and MS image. The proposed method simultaneously provides richer information in the spatial and spectral domains. 相似文献
15.
The reliability of habitat maps that have been generated using Geographic Information Systems (GIS) and image processing of remotely sensed data can be overestimated. Habitat suitability and spatially explicit population viability models are often based on these products without explicit knowledge of the effects of these mapping errors on model results. While research has considered errors in population modeling assumptions, there is no standardized method for measuring the effects of inaccuracies resulting from errors in landscape classification. Using landscape‐scale maps of existing vegetation developed for the USDA Forest Service in southern California from Landsat Thematic Mapper satellite data and GIS modeling, we performed a sensitivity analysis to estimate how mapping errors in vegetation type, forest canopy cover, and tree crown size might affect delineation of suitable habitat for the California spotted owl (Strix occidentalis occidentalis). The resulting simulated uncertainty maps showed an increase in the estimated area of suitable habitat types. Further analysis measuring the fragmentation of the additional patches showed that they were too small to be useful as habitat areas. 相似文献
16.
Qingmin Meng Chris Cieszewski Marguerite Madden 《ISPRS Journal of Photogrammetry and Remote Sensing》2009,64(1):27-36
Large area forest inventory is important for understanding and managing forest resources and ecosystems. Remote sensing, the Global Positioning System (GPS), and geographic information systems (GIS) provide new opportunities for forest inventory. This paper develops a new systematic geostatistical approach for predicting forest parameters, using integrated Landsat 7 Enhanced Thematic Mapper Plus (ETM+) images, GPS, and GIS. Forest parameters, such as basal area, height, health conditions, biomass, or carbon, can be incorporated as a response variable, and the geostatistical approach can be used to predict parameter values for uninventoried points. Using basal area as the response and Landsat ETM+ images of pine stands in Georgia as auxiliary data, this approach includes univariate kriging (ordinary kriging and universal kriging) and multivariable kriging (co-kriging and regression kriging). The combination of bands 4, 3, and 2, as well as the combination of bands 5, 4, and 3, normalized difference vegetation index (NDVI), and principal components (PCs) were used in this study with co-kriging and regression kriging. Validation based on 200 randomly sampling points withheld field inventory was computed to evaluate the kriging performance and demonstrated that band combination 543 performed better than band combination 432, NDVI, and PCs. Regression kriging resulted in the smallest errors and the highest R-squared indicating the best geostatistical method for spatial predictions of pine basal area. 相似文献
17.
Diofantos G Hadjimitsis 《Transactions in GIS》2008,12(5):633-644
Satellite sensors have provided new datasets for monitoring regional and urban air quality. Satellite sensors provide comprehensive geospatial information on air quality with both qualitative remotely sensed imagery and quantitative data, such as aerosol optical depth which is the basic unknown parameter for any atmospheric correction method in the pre‐processing of satellite imagery. This article presents a new method for retrieving aerosol optical thickness directly from satellite remotely sensed imagery for short wavelength bands in which atmospheric scattering is the dominant contribution to the at‐satellite recorded signal. The method is based on the determination of the aerosol optical thickness through the application of the contrast tool (maximum contrast value), the radiative transfer calculations and the ‘tracking’ of the suitable darkest pixel in the scene. The proposed method that needs no a‐priori information has been applied to LANDSAT‐5 TM, LANDSAT‐7 ETM+, SPOT‐5 and IKONOS data of two different geographical areas: West London and Cyprus. The retrieved aerosol optical thickness values show high correlations with in‐situ visibility data acquired during the satellite overpass. Indeed, for the West London area a logarithmic regression was fitted for relating the determined aerosol optical thickness with the in‐situ visibility values. A high correlation coefficient (r2= 0.82; p= 0.2) was found. Plots obtained from Tanre et al. (1979, 1990) and Forster (1984 ) were reproduced and estimates for these areas were generated with the proposed method so as to compare the results. The author's results show good agreement with Forster's aerosol optical thickness vs. visibility results and a small deviation from Tanre's model estimates. 相似文献
18.
Topographic information from maps and geographical information systems (GIS) has been combined with satellite data (SPOT Panchromatic, SPOT Multispectral and Landsat Thematic Mapper) to derive a product that may be valuable in preliminary route location studies. The objectives of this study were to evaluate the classification accuracy of this combined product, to compare levels of ground detail obtainable from different types of satellite imagery against aerial photography, and to present an example application on the use of the combined product.
The classification accuracy of the combined product was dependent on the type of land cover and was 83 to 100 per cent successful, with accuracy exceeding 95 per cent for most land cover types. The overall accuracy of the product was almost 95 per cent, with accuracy based on KHAT statistics of 92 per cent. Varying levels of ground detail were attainable from different types of satellite imagery. This detail may be adequate for preliminary route selection, especially in the absence of aerial photographs and GIS. The combined product presented in this study was applied successfully in selecting the optimal route for the Greater Amman ring road. 相似文献
The classification accuracy of the combined product was dependent on the type of land cover and was 83 to 100 per cent successful, with accuracy exceeding 95 per cent for most land cover types. The overall accuracy of the product was almost 95 per cent, with accuracy based on KHAT statistics of 92 per cent. Varying levels of ground detail were attainable from different types of satellite imagery. This detail may be adequate for preliminary route selection, especially in the absence of aerial photographs and GIS. The combined product presented in this study was applied successfully in selecting the optimal route for the Greater Amman ring road. 相似文献
19.
B. S. Sokhi N. D. Sharma P. S. Uttarwar 《Journal of the Indian Society of Remote Sensing》1989,17(3):57-69
Visual interpretation of satellite data products coupled with field checking is a very useful technique of finding out the physical growth of urban centres. The expansion of urban centres is very fast and conventional ground methods are slow and in-accurate because by these methods, delineation of built-up area is difficult. Mapping and monitoring the urban sprawl, as a result of urban decay of city centre, at regular intervals is very essential for urban planners to understand the trend of development on the urban periphery and subsequently to regulate it. In this study, various data products like Landsat MSS, TM, Toposheets were used to find out the growth of Delhi urban area since 1975 to 1988. Thematic Mapper imagery was used to prepare a broad landuse/land cover map of Delhi and environs. This study was very useful in finding out the potential, as well as shortcomings of satellite data products in the study of various urban aspects. 相似文献
20.
Youshui Zhang Inakwu O.A. Odeh Chunfeng Han 《International Journal of Applied Earth Observation and Geoinformation》2009
As more than 50% of the human population are situated in cities of the world, urbanization has become an important contributor to global warming due to remarkable urban heat island (UHI) effect. UHI effect has been linked to the regional climate, environment, and socio-economic development. In this study, Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) imagery, respectively acquired in 1989 and 2001, were utilized to assess urban area thermal characteristics in Fuzhou, the capital city of Fujian province in south-eastern China. As a key indicator for the assessment of urban environments, sub-pixel impervious surface area (ISA) was mapped to quantitatively determine urban land-use extents and urban surface thermal patterns. In order to accurately estimate urban surface types, high-resolution imagery was utilized to generate the proportion of impervious surface areas. Urban thermal characteristics was further analysed by investigating the relationships between the land surface temperature (LST), percent impervious surface area, and two indices, the Normalized Difference Vegetation Index (NDVI) and Normalized Difference Built-up Index (NDBI). The results show that correlations between NDVI and LST are rather weak, but there is a strong positive correlation between percent ISA, NDBI and LST. This suggests that percent ISA, combined with LST, and NDBI, can quantitatively describe the spatial distribution and temporal variation of urban thermal patterns and associated land-use/land-cover (LULC) conditions. 相似文献