基于地面定标技术的地物光谱反演方法研究

阐述了利用地面光谱定标和实验室遥感仪器定标技术和遥感方程对成像光谱遥感数据进行反射率反演的理论基础、技术方案及操作规范。结合航空遥感飞行试验,对成像光谱遥感数据进行了地物反射率反演,并讨论分析了该方法的可行性条件。研究结果表明:(1)该方法简便、实用、可行;(2)地面定标点的选择及光谱测量精度是影响反射率反演准确性的主要因素;(3)遥感器的几何参量、遥感数据获取的时间跨度、地形因子及二向反射因素是造成反射率反演误差的重要原因,在实际应用中也应加以重视。     

沉积岩石信息的热红外多光谱遥感探测及有效性评价

在对热红外多光谱（ＴＩＭＳ）遥感的探测机理及其图像专题信息提取方法的综合分析基础上，以不同沉积岩石的化学成分，矿物组成，结构，反射和发射光谱特征的实验室分析温度测试结果为依据，对不同沉积岩石的热红外多光谱遥感成像机制进行了探讨，并对比分析了不同沉积岩石ＴＩＭＳ图像和ＴＭ图像的识别效果。     

勇往直前──MDI发布ADAMS10.0

国ＭＤＩ（Ｍｅｃｈａｎｉｃａｌ　Ｄｙｎａｍｉｃｓ　Ｉｎｃ）公司于近日在京发布了ＡＤＡＭＳ１０．０（ＡｕｔｏｍａｒｉｃＤｙｎａｍｉｃ　Ａｎａｌｙｓｉｓ　ｏｆ　ＭｅｃｈａｎｉｃａｌＳｙｓｔｅｍ））版本。ＭＤＩ公司同时发布了三个新模块,即Ｅｎｇｉｎｅ（发动机系统设计软件包）、Ｈｙｄｒａｕｌｉｃ（液压系统设计软件包）、ＰｏｓｔＰｅｏｅｓｓｏｒ（数据后处理模块）。ＭＤＩ公司开发的ＡＤＡＭＳ是世界上最权威的机械系统动力学分析软件,全球市场占有率超过７０％。它可以自动生成包括机－电－液一体化的复杂机械系统的多…     

ERDAS IMAGINE─遥感业界的先驱

ＥＲＤＡＳＩＭＡＧＩＮＥ─遥感业界的先驱戎兵，王彻（富融科技有限公司）１９７８年在美国佐治亚州的亚特兰大市创办的ＥＲ－ＤＡＳ公司，如今已成为全球最大的专业遥感图像处理软件公司。近２０年来，ＥＲＤＡＳ公司一直致力于遥感图像处理系统技术的开发应用和服务，...     

用SIMAN遗留代码建立32位Windows仿真应用程序

文章详细讨论了对ＤＯＳ环境下的ＳＩＭＡＮ仿真语言进行３２位Ｗｉｎｄｏｗｓ化改造（Ｗｉｎ_ＳＩＭＡＮ）的过程和方法。并且完整地讨论了用Ｍｉｃｒｏｓｏｆｔ Ｆｏｒｔｒａｎ ＰｏｗｅｒＳｔａｔｉｏｎ ４．０、Ｍｉｃｒｏｓｏｆｔ ＶｉｓｕａｌＣ＋＋５．０和Ｗｉｎ_ＳＩＭＡＮ创建３２位Ｗｉｎｄｏｗｓ仿真应用程序的方法和注意事项。关键部分用源代码加以说明并已调试通过。     

HJ-1A高光谱数据高效大气校正及应用潜力初探

环境与灾害监测预报小卫星于2009年3月30日开始正式交付使用,A星上搭载了我国自主研制的空间调制型干涉高光谱成像仪（HSI）,作为一种新型传感器,HSI数据的应用在我国还处于探索阶段。要充分发挥超光谱数据优势、进行有效的遥感应用,首先需要消除遥感成像过程中的大气影响,获得不同波段的地物真实反射辐射信息。通过使用FLAASH大气辐射传输模型对HSI数据进行大气校正,并与表观反射率进行对比分析,证明了校正后获得的地表光谱反射率的有效性。同时基于校正后得到的光谱反射率图像,进行改良型土壤调整植被指数（MSAVI）与叶面积指数（LAI）的反演,初步展现了HSI数据的实际应用效果。     

N—甲基—D,L—天门冬氨酸对肥育猪生长性能的影响

用１２０头杜大长肥育猪分别研究口服不同剂量Ｎ－甲基－Ｄ,Ｌ－天门冬氨酸（ＮＭＡ）对猪生长性能的影响,并分析了５０ｍｇ／ｋｇＮＭＡ对猪消化性能和血清激素水平的影响。试验表明：①添加ＮＭＡ均不同程度地提高了日增重,降低了料重比。其中５０ｍｇ／ｋｇＮＭＡ组效果最佳,日增重提高了９．６５％（Ｐ＜０．０２）,料重比降低了９．５９％（Ｐ＜０．０１）;②５０ｍｇ／ｋｇＮＭＡ使饲料中粗蛋白、粗脂肪的表观消化率分别提高了４．３９％（Ｐ＜０．０１）、２６．６１％（Ｐ＜０．０２）,而对干物质和粗灰分的表观消化率无明显影响（Ｐ＞０．０５）;③在添加５０ｍｇ／ｋｇＮＭＡ组,猪血清ＧＨ、ＩＧＦ－Ｉ、Ｉｎｓｕｌｉｎ水平分别提高了１１７．１９％（Ｐ＜０．０１）、９２．８９％（Ｐ＜０．０１）、４８．２９（Ｐ＜０．０５）。     

不断发展的ERDAS IMAGINE(一)──遥感领域专业分析软件的排头兵

１ＥＲＤＡＳ公司及产品ＥＲＤＡＳＩＭＡＧＩＮＥ是美国ＥＲＤＡＳ公司开发的遥感图像处理系统,它以其先进的图像处理技术,友好、灵活的用户界面和操作方式,面向广阔应用领域的产品模块,服务于不同层次用户的模型开发工具以及高度的ＲＳ／ＧＩＳ（遥感图像处理和地理...     

下一代永久性存储器(FRAM)

下一代永久性存储器（ＦＲＡＭ）Ｒｏｈｍ和ＩｎｔａｇＩｎｔｅｒｎａｔｉｏｎ合作开发的新产品，用于航空包裹邮寄标记的肤入式ＦＲＡＭ单片大规模集成电路（ＬＳＩ）。这种单片ＬＳＩ的特点在于其带有嵌人式铁氧体存储器。”这种单片ＬＳＩ可广泛应用于航空、邮电、金融...     

集成系统获奖软件介绍

集成系统获奖软件介绍集成化ＣＡＤ／ＣＡＭ支撑软件系统ＧＨＣＡＤＭＩＳ１．０（工作站版）一、概况ＧＨＣＡＤＭＩＳ１．０是由清华大学、华中理工大学和大连理工大学紧密联合、优势互补、综合渗透，经过近１００人三年多的努力奋斗，于１９９５年３月２０日推出的有我...     

机载成像光谱图象边缘辐射畸变校正

由于受大气效应、地物反射非朗伯特性、仪器－太阳－目标相对几何关系以及仪器系统本身特性等多种因素的影响,机载成像光谱数据中不可避免地将引入系统或非系统的辐射畸变,严重地影响了数据表达信息的可靠性和有效性。目前虽然已有一些机载遥感图像辐射畸变校正方法,但由于受各种应用条件的限制,所发展的这些方法普遍缺乏实用性和通用性。该文在对机载成像光谱图象边缘辐射畸变形机制进行理论分析和探讨的基础上,针对机载成像光     

Imaging spectrometry data correlated to hydrocarbon microseepage

Modular Airborne Imaging Spectrometer (MAIS) data were used to map hydrocarbon microseepages in the Weibei Depression, People's Republic of China, as an aid to petroleum exploration. To convert the radiance data to reflectance, the Empirical Line Method was used and the resulting data were similar to the field spectra. After first delineating the wheat fields, three bands (at 719.75nm, 739nm and 758.25nm) were used to map the pixels that had a red shift. A neighbourhood summation function was applied to evaluate which pixels were more likely to be anomalies. The non-systematic geometric distortions were corrected with the aid of linear features in the image and subsequently the systematic geometric distortions were corrected using ground control points. Ethane concentrations of 217 soil samples were used to assess the mapping result. It appears that high ethane concentrations in the map area are positively correlated to red-edge shift, which suggests that a high ethane concentration in soil may cause red-edge shift in wheat spectra. However, sub-surface structure and stratigraphy must be considered as well when analysing MAIS data.     

MODIS气溶胶光学厚度产品和激光雷达数据在大气颗粒物监测中的应用

遥感反演是区域尺度上近地面颗粒物数据获取的有效手段。利用激光雷达观测的消光系数垂直分布、地面相对湿度、风速等数据,对无锡市MODIS(中分辨率成像光谱仪)气溶胶光学厚度(AOD)产品进行垂直、湿度和风速订正,并用研究区域中7个地面站点的PM_(10)和PM_(2.5)浓度监测数据对订正结果进行评估。结果表明:经过订正的MODIS AOD产品与地面监测数据具有良好的相关性,其中与PM_(10)的决定系数达到0.452,与PM_(2.5)的决定系数达到0.449,说明MODIS AOD产品经相关订正后,可用于无锡及其附近地区地面空气污染的监测。在MODIS AOD产品的垂直订正方面,利用激光雷达数据的订正效果好于利用能见度数据的订正效果。在遥感与实测数据的相关性季节变化方面,夏季相关性最高,秋季次高,春季较低,冬季最低。     

Geo-atmospheric processing of airborne imaging spectrometry data. Part 2: Atmospheric/topographic correction

A method for the radiometric correction of wide field-of-view airborne imagery has been developed that accounts for the angular dependence of the path radiance and atmospheric transmittance functions to remove atmospheric and topographic effects. The first part of processing is the parametric geocoding of the scene to obtain a geocoded, orthorectified image and the view geometry (scan and azimuth angles) for each pixel as described in part 1 of this jointly submitted paper. The second part of the processing performs the combined atmospheric/ topographic correction. It uses a database of look-up tables of the atmospheric correction functions (path radiance, atmospheric transmittance, direct and diffuse solar flux) calculated with a radiative transfer code. Additionally, the terrain shape obtained from a digital elevation model is taken into account. The issues of the database size and accuracy requirements are critically discussed. The method supports all common types of imaging airborne optical instruments: panchromatic, multispectral and hyperspectral, including fore/aft tilt sensors covering the wavelength range 0.35-2.55 w m and 8-14 w m. The processor is designed and optimized for imaging spectrometer data. Examples of processing of hyperspectral imagery in flat and rugged terrain are presented. A comparison of ground reflectance measurements with surface reflectance spectra derived from airborne imagery demonstrates that an accuracy of 1-3% reflectance units can be achieved.     

Surface mineral mapping of Makhtesh Ramon Negev,Israel using GER 63 channel scanner data

Geophysical and Environmental Research (GER) 63 channel scanner data were used to map the surface mineralogy of Makhtesh Ramon, Negev, Israel. The data werecorrected to reflectance using the Internal Average Relative Reflectance (IARR) method and analysed using colour-composites, the Spectral Angle Mapper (SAM), and linear spectral unmixing (UNM). Results demonstrate that imaging spectrometer data can be used to produce detailed mineralogical maps in arid terrains even when no calibration measurements are made during the flights and no ground measurements are available. The mineralogical maps produced using the GER data compare favourably to the known surface mineralogy, however, they provide greater detail regarding composition and mineral abundance than the existing geological maps.     

Evaluation of apparent surface reflectance estimation methodologies

The estimation of apparent surface reflectance values from imaging spectroscopy data requires a correction for the efTects of the intervening atmosphere. Four methods of estimating apparent surface reflectance have been evaluated, the empirical line method and three methods of radiative transfer modelling. To compare the results of these correction methodologies two high albedo targets, of identified composition, were selected. The empirical line method was found to be sensitive to errors in locating and spectral variations within the ground survey targets and also target height differences. The radiative transfer modelling techniques gave relatively similar results, reasonably close to the library spectra. This study indicates that radiative transfer modelling using only atmospheric information derived from the imaging spectroscopy data, while still not as sensitive as correction methods using additional ground and atmospheric information, can satisfactorily correct the atmospheric elfects involved in estimating apparent surface reflectance, allowing the identification of the major diagnostic absorption features.     

Validating the use of metre-scale multi-spectral satellite image data for identifying tropical forest tree species

Identifying and mapping tropical trees at the species level from space can support an improved assessment of forest composition, forest carbon uptake, tree species distribution and preferred habitat as well as a better understanding of the response of forests to climate change. In this study, the development of a validated data and image-processing schema demonstrated the capability of current metre-scale satellite technology (WorldView-3) to identify specific tree species within an unmanaged tropical forest. The experimental site, La Selva Biological Station in Costa Rica, provided access for field validation and spectral data acquisition of individual tree canopies from established canopy towers. It is also a representative biome of diverse lowland Atlantic tropical forests in Central America. The process defined in this paper calibrated and corrected field-acquired ASD field spectra for ten tree species and corrected WorldView-3 image data for viewing and illumination geometry. In addition, assessments of three current atmospheric compensation methods for correcting recent WorldView-3 satellite imagery established the most accurate compensation process for a tropical forest setting. Corrected reflectance in the satellite data matched the spectrometer data to ±0.25% for visible bands and ±0.5% for near-infrared bands. This study shows that spectral data from the satellite and field spectrometer data are nearly equivalent when applying the appropriate atmospheric compensation, band response emulation, and viewing correction processes established in this study.     

The effects of vegetation on the ability to map soils using imaging spectrometer data

Remote sensing applied to tasks of mapping soil and rock surfaces must address the problem of vegetation cover in all but the most arid terrain. Masking out pixels with a high proportion of vegetation using a threshold on the near-infrared/red ratio is a popular strategy for live vegetation. The important effects of dead vegetation on the SWIR reflectance is usually ignored. Data gathered by the GER-II imaging spectrometer over a semi-arid area near Almaden, south central Spain were used to test the sensitivity of thematic soil mapping to variable cover of live and dead vegetation. After calibration to reflectance a least-squares unmixing analysis was performed using image end-members and proportions maps of vegetation and soil/rock components generated. Despite a low signal-to-noise ratio, three soil/rock and four vegetation endmembers were successfully mapped and validated from field estimates. A quantitative assessment was made of the effects of live and dead vegetation on the ability of the unmixing analysis to distinguish between granite and shale soils using synthetically mixed spectra gathered using field spectroradiometry and statistical analysis of the imaging spectrometer data. Dead vegetation was shown to have a greater impact on soil spectra than live vegetation. The ability to distinguish between the soils was lost at 50-60 per cent vegetation cover.     

A simplified method for retrieval of ground level reflectance of targets from airborne video imagery

This paper describes an efficient method for retrieval of ground reflectance characteristics of targets from calibrated multispectral airborne video data for routine operational airborne missions. The method uses a simplified atmospheric scattering model in combination with a dark-object subtraction procedure to estimate the effect of the atmosphere in the path between the target and the sensor, as well as the adjacent environmental effect, on the radiation signal received by an airborne sensor. The simplicity of the atmospheric scattering model is maintained by the assumption that the air density within the targetsensor path in the lower atmosphere is sufficiently uniform for operations of the Charles Sturt University's (CSU) Multispectral Airborne Video System (MAVS). The MAVS acquires imagery in blue, green, red and near-infrared (NIR) narrow spectral bands. The MAVS is radiometrically calibrated and has a consistent radiometric response in-flight. An important feature of the new method is the coupling of the image based brightness data (DN) of a dark-object and the system radiometric calibration coefficients to determine the path reflectance and the environmental reflectance of the target. The sum of the path reflectance and the environment reflectance is known as haze reflectance. The haze reflectance indicates the amount of atmospheric haze in the airborne imagery. The simplified atmospheric model is then employed to determine the actual ground reflectance of the targets using the haze subtracted apparent (total) reflectance of the target at the altitude of the airborne sensor. The apparent reflectance of the target at the sensor altitude is obtained directly from the image based DN data and the system radiometric calibration coefficients. An interesting aspect of this simplified method is that an estimate of the environmental reflectance can be obtained as a by-product of the atmospheric haze calculation using a dark-object subtraction technique. The retrieved ground reflectance characteristics from calibrated MAVS imagery are now being used routinely for remote quantitative monitoring of agricultural and environmental targets.