卫星传感器波段平均太阳辐照度计算及可靠性分析   总被引：1，自引：0，他引：1  

胡顺石  张立福  张霞  王倩  韩冰  张楠 《国土资源遥感》2012,(3):97-102

地球大气层外太阳光谱辐照度(extraterrestrial solar spectral irradiance,ESSI)数据是计算卫星传感器波段平均太阳辐照度(band mean solar irradiance,BMSI)的重要参数。为了探求利用何种来源的ESSI数据计算传感器BMSI更为准确,分别采用SBDART软件模拟的太阳光谱曲线数据、MODTRAN4.0 oldkur.dat文件数据、Thuillier太阳光谱曲线数据和WRC太阳光谱曲线数据计算了HJ-1A CCD1(B1—B4),CBERS-02 CCD(B1—B5),Landsat5TM(B1—B4)和ASTER(B1—B8)4种传感器的BMSI,并与传感器运营商公布的数据进行了比较。结果表明:利用SBDART和WRC太阳光谱曲线数据计算的结果误差较小;利用MODTRAN4.0 oldkur.dat数据计算的结果误差次之;利用Thuillier太阳光谱曲线的计算结果误差较大。  相似文献   

鄂东南尾矿库高分辨率遥感图像识别因子研究   总被引：1，自引：0，他引：1  

郝利娜  张志  何文熹  陈腾 《国土资源遥感》2012,(3):154-158

正在使用的尾矿库中,尾砂的极细小颗粒特征决定了其在各波段遥感图像上具有较高反射率的光谱特征;尾砂的堆积过程则同时决定了尾矿库表面具有大致平行的分带纹理和放射状纹理特征。从尾砂的光谱、纹理特征以及与尾矿库相关的其他因素(道路、矿山建筑、尾矿库地理位置等)出发,系统建立了鄂东南地区金属矿山尾矿库的高分辨率遥感图像的综合识别标志。依据所建立的综合识别标志,可从WorldView-2图像中准确地识别尾矿库,并初步判断其规模。  相似文献   

两种高光谱热红外数据大气校正方法的分析与比较     

周孝明  王宁  吴骅 《遥感学报》2012,16(4):796-808

利用模拟数据对Autonomous Atmospheric Compensation(AAC)和In-scene Atmospheric Compensation(ISAC)这两种高光谱热红外数据大气校正方法进行了对比和分析。结果显示,在满足方法适用条件情况下,AAC方法大气校正精度较高,除湿热的热带大气外,大气透过率的反演误差小于0.02,大气上行辐射的误差小于0.004W.m-2.sr-1.cm;而ISAC方法精度较低,透过率误差在0.05至0.3之间,上行辐射误差在0.003W.m-2.sr-1.cm至0.035W.m-2.sr-1.cm之间变化,误差随大气水汽含量增加而增加。大气非均一性对大气校正精度影响分析表明,AAC方法大气校正精度受大气非均一性影响显著。因此,需从高光谱数据光谱信息出发,发展针对低空间分辨率高光谱热红外数据的大气校正方法,以克服现有方法大气水平均一假设的不足。  相似文献   

C3、C4作物的光保护机制差异的光谱探测研究   总被引：1，自引：0，他引：1  

刘良云  关琳琳  彭代亮  胡勇  刘玲玲 《遥感学报》2012,16(4):783-795

本文设计了大豆(C3作物)和玉米(C4作物)日变化光谱探测试验,提取了太阳光照条件下叶绿素荧光信号和光化学指数PRI。结果表明,首先大豆和玉米叶绿素荧光强度的日变化特征有较大差异,上午大豆的叶绿素荧光比例呈现快速增加的趋势,而玉米的叶绿素荧光未出现增加趋势;其次,下午高温胁迫条件下C3、C4叶绿素荧光光谱比值的变化差异显著,大豆在760nm和688nm波段的叶绿素荧光比值快速增加,而玉米未出现显著变化;最后,研究证实了C3作物中午受到强光抑制出现光合作用"午休"现象,即午后光合恢复后其光合效率快速增加,表现为C3作物的热耗散降低、PRI快速增加,而C4作物无"午休"现象,午后PRI增加较小。本文研究表明,强光和高温环境胁迫下C3、C4作物的叶绿素荧光和热耗散变化特征有较大差异,利用胁迫条件下的多时相、高光谱遥感数据,提取C3、C4作物的叶绿素荧光和PRI,有可能实现C3、C4作物的遥感分类目标。  相似文献   

基于独立成分分析的高光谱变化检测   总被引：1，自引：0，他引：1  

武辰  杜博  张良培 《遥感学报》2012,16(3):545-561

现有的变化检测方法并未充分研究变化前后高光谱遥感影像端元的联系,不能准确地分析地物变化信息。本文提出了一种基于独立成分分析的高光谱遥感影像变化检测方法,对差值影像进行基于偏斜度的独立成分分析,在不同组分图中分别显示单一地物的变化情况,进而提取变化信息。实验表明,该方法能够在获得较高检测率的同时维持较低的误检率,检测效果优于传统方法。  相似文献   

一种融合中分辨率多光谱与高分辨率全色图像的方法     

王忠武  刘顺喜 《地理与地理信息科学》2012,28(4):42-45,2

针对中分辨率多光谱与高分辨率全色图像空间分辨率差异大,导致融合结果难以较好平衡光谱信息保持和空间信息保持能力的问题,该文分析了7种常用融合方法用于中分辨率多光谱与高分辨率全色图像融合的优缺点及其融合质量的影响因素,提出了一种组合融合方法。该方法在保留Gram-Schmidt方法的细节注入方式的基础上,综合利用高通滤波法和Gram-Schmidt方法的优势构造低分辨率全色图像,确保在提高融合图像空间分辨率的同时有效降低其光谱变形。通过CBERS-02多光谱和IRS-P5全色图像的实验,证明了新融合方法的有效性。  相似文献   

Late-time photometry of two nearby type II-P supernovae： 2004dj and 2004et     

Tian-Meng Zhang Xiao-Feng Wang Xu Zhou Jun Ma Zhao-Ji Jiang Jiang-Hua Wu Zhen-Yu Wu Stephane Basa 《天体物理学报》2009,(7):783-790

We present late-time photometry for two bright type II-P supernovae （SNe） 2004dj and 2004et, extending over 400 d after the explosion, which are measured with a set of intermediate-band filters that have the advantage of tracing the strength variations of some spectral features. Although these two SNe II-P exhibit similar photometric evolution at earlier times, they diverge during the nebular phase. SN 2004dj shows a slow late-time decline rate with - 0.7 ±0.1 mag （100d）^-1 during the period ranging from t ≈ 200 - 300 d after the explosion, while SN 2004et shows a much faster decline rate at a comparable phase, e.g., 1.3 ± 0.1 mag （100d）^-1. The steeper decay rate seen in SN 2004et is likely due to dust formation in the explosion ejecta. Based on intermediate-band photometry, we derived the evolution of the feature lines [e.g., Hα] of SNe 2004dj and 2004et which are similar in flux at comparable phases but perhaps with significantly different decay rates. The origin of the observed variations in the continuum and the feature lines is briefly discussed.  相似文献   

群星的族谱——天文学星表纵览（5）     

余恒 《天文爱好者》2009,(7):32-33

（接上期） 二十世纪初摄影术的出现,不仅自身成为天文研究的得力工具,还唤醒了沉寂多年的分光术。虽然早在1817年普鲁士的夫朗和费（Joseph Fraunhofer）就用自己发明的分光计发现了太阳光谱中的暗线。  相似文献   

A modified stratified model for the 3C 273 jet     

Wen-Po Liu Zhi-Qiang Shen 《中国天文和天体物理学报》2009,9(5)

We present a modified stratified jet model to interpret the observed spectral energy distributions of knots in the 3C 273 jet. Based on the hypothesis of the single index of the particle energy spectrum at injection and identical emission processes among all the knots, the observed difference of spectral shape among different 3C 273 knots can be understood as a manifestation of the deviation of the equivalent Doppler factor of stratified emission regions in an individual knot from a characteristic one. The summed spectral energy distributions of all ten knots in the 3C 273 jet can be well fitted by two components: a low-energy component (radio to optical) dominated by synchrotron radiation and a high-energy component (UV, X-ray and γ-ray) dominated by inverse Compton scattering of the cosmic microwave background. This gives a consistent spectral index of α= 0.88 (Sv α v-α) and a characteristic Doppler factor of 7.4. Assuming the average of the summed spectrum as the characteristic spectrum of each knot in the 3C 273 jet, we further get a distribution of Doppler factors. We discuss the possible implications of these results for the physical properties in the 3C 273 jet. Future GeV observations with GLASTcould separate the γ-ray emission of 3C 273 from the large scale jet and the small scale jet (i.e.the core) through measuring the GeV spectrum.  相似文献   

Automated spectral classification using template matching     

Fu-Qing Duan Rong Liu Ping Guo Ming-Quan Zhou Fu-Chao Wu 《中国天文和天体物理学报》2009,9(3)

An automated spectral classification technique for large sky surveys is pro-posed. We firstly perform spectral line matching to determine redshift candidates for an observed spectrum, and then estimate the spectral class by measuring the similarity be-tween the observed spectrum and the shifted templates for each redshift candidate. As a byproduct of this approach, the spectral redshift can also be obtained with high accuracy. Compared with some approaches based on computerized learning methods in the liter-ature, the proposed approach needs no training, which is time-consuming and sensitive to selection of the training set. Both simulated data and observed spectra are used to test the approach; the results show that the proposed method is efficient, and it can achieve a correct classification rate as high as 92.9%, 97.9% and 98.8% for stars, galaxies and quasars, respectively.  相似文献