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A fusion algorithm for remote sensing images based on nonsubsampled pyramids and bidimensional empirical decomposition

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Science china(Technological Sciences) 2010年第S1期53卷 196-204页

作者： ZHANG XiaoDong 1,WANG WenBo 2,WANG DiFeng 3.& ZHANG Yu 4 1 state Key Laboratory of Information Engineering in surveying,mapping and Remote Sensing,Wuhan University,Wuhan 43.079,{3. 2 College of Sciences,Wuhan University of Science and Technology,Wuhan 43.065,{3. 3.0} Key Laboratory of satellite Ocean Environment Dynamics,Second Institute of Oceanography,state Oceanic Administration,Hangzhou 3.0012,{3. 4 Spatial Information Technology application Research Institute,Changjiang River Scientific Research Institute,Wuhan 43.010,{3. state Key Laboratory of Information Engineering in surveying Mapping and Remote Sensing Wuhan University Wuhan China College of Sciences Wuhan University of Science and Technology Wuhan China state Key Laboratory of satellite Ocean Environment Dynamics Second Institute of Oceanography State Oceanic Administration Hangzhou China Spatial Information Technology application Research Institute Changjiang River Scientific Research Institute Wuhan China

In order to improve the quality of remote sensing image fusion,a new method combining nonsubsampled Laplacian pyramid (NLP)and bidimensional empirical mode decomposition(BEMD)is ***,the high resolution panchromatic image (PAN)is decomposed using NLP until the approximate component and the low resolution multispectral image(MS)contain features with a similar ***,the approximation component and the MS are decomposed by BEMD,resulting in a number of bidimensional intrinsic mode functions(BIMF)and a residue *** instantaneous frequency is computed in 4 directions of the *** the positive or negative coefficients in the corresponding position,a weighted algorithm is designed for fusing the high frequency details using the instantaneous frequency and the coefficient absolute value of the BIMFs as fusion *** fused image is then obtained through inverse BEMD and *** results have illustrated the advantage of this method over the IHS,DWT andà-Trous wavelet in both spectral and spatial detail qualities.

关键词： bidimensional empirical mode decomposition nonsubsampled pyramid instantaneous frequency remote sensing image fusion

Water target based cross-calibration of CBERS-02 CCD camera with MODIS data

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Science china(Technological Sciences) 2005年第S2期48卷 61-71页

作者： TANG Junwu1,2, GU Xingfa2, NIU Shengli1, MA Chaofei1 & MIN Xiangjun3.1. National satellite Ocean application Service (NSOAS), Beijing 100081, china 2. {3. Key Laboratory of Remote Sensing Science, Beijing 100010, china 3. china center for Resource satellite Data and applications (CRESDA), Beijing 100083. china National satellite Ocean application Service (NSOAS) Beijing 100081 China

In order to make quantitative watercolor sensing with china-Brazil Earth Resources satellite (CBERS-02) CCD camera, the MODIS data with higher accuracy is used to cross-calibrate the CCD camera over water targets. In homogeneous clear water area, two pairs of images obtained over the same area on the same day by the two sensors are selected. The top-of-atmosphere (TOA) radiances of the multispectral bands of CCD are calculated with the water and aerosol parameters from MODIS based on a water-atmosphere radiative transfer algorithm. The stripes in CCD image that caused by unequal response of the CCD array detectors are firstly removed before making the cross-calibration. The same part of CCD detectors is selected for the calibrations in the two images to eliminate the residual error of destriping and uniformity correction for the focus plane irradiance. It is shown that the calibration results from two different images are consistent. The error of this method is about 5%.

关键词： CBERS-02 CCD MODIS radiometric calibration cross-calibration. DOI: 10.13.0/05ze1006

The quantification of remote sensing

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Science china(Technological Sciences) 2005年第S2期48卷 1-11页

作者： GU Xingfa1,2,3.TIAN Guoliang1,2, LI Xiaowen1,2 & GUO Jianning4 1. state Key Laboratory of Remote Sensing Science, Jointly Sponsored by the Institute of Remote Sensing applications of Chinese Academy of Sciences and Beijing Normal University, Beijing 100101, china 2. The {3. for National Spaceborne Demonstration, Beijing 100101, china 3. Institut National de la Recherche Agronomique, Climat Sol Environnement, 84914 Avignon, France 4. china {3. for Resource satellite Data and application, Beijing 10083., china state Key Laboratory of Remote Sensing Science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing 100101 China

The paper firstly defined the remote sensing information quantification, analyzed the necessity of developing remote sensing quantification, figured out the application guidelines requirement, and pointed out the importance of quantification research. Then taking the remote sensing application research of CBERS-02 data quantification as the example, the paper described the whole quantification system of “remotely sensed digital signal-radiation information-field parameter inversion”. Finally the paper gave the prospect for the development trend of the quantitative remote sensing.

关键词： remote sensing information quantification CBERS-02 radiometric calibration surface parame- ter reversion.

Wetland hydrologic application of satellite altimetry-A case study in the Poyang Lake watershed

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Progress in Natural Science:Materials International 2009年第12期19卷 1781-1787页

作者： Xiaobin Cai~(a,b),Wei Ji~(b,*) a state Key Laboratory of Information Engineering in surveying,mapping and Remote Sensing,Wuhan University,Wuhan 43.079,{3. b Department of Geosciences,University of Missouri,Kansas City,Kansas City,MO 64110,USA state Key Laboratory of Information Engineering in surveying Mapping and Remote Sensing Wuhan University Wuhan 430079 China Department of Geosciences University of Missouri Kansas City Kansas City MO 64110 USA

Hydrologic variation affects many functions of *** and accurately measuring hydrologic dynamics in a wetland watershed has become a fundamental need for estimating functional changes of *** satellite altimeters have become good data sources that can complement the measurements of gauge *** a case project applied in the Poyang Lake watershed,this study has developed a technical approach that integrates the altimeter measurements with the in situ water level *** derived water surface heights with Envisat RA-2 data are compared with the daily observations of in situ water *** average absolute observation difference between the"altimeter station"and its nearest gauge station is 0.3.7 m,which is comparable to the average differences among the gauge *** results suggest that the derived water surface heights from the altimeter data have a good accuracy,which can be used along with the in situ observations as supplements to fill the ungauged area in Poyang Lake wetlands.

关键词： satellite altimetry Wetland hydrology Poyang Lake

GRACE detection of the medium-to far-field coseismic gravity changes caused by the 2004 Mw9.3.Sumatra-Andaman earthquake

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Earthquake Science 2012年第3期25卷 235-240页

作者： Jin Li1,2,3.and Wenbin Shen1,3.4, 1 Department of Geophysics, School of Geodesy and Geomatics, Wuhan University, Wuhan 43.079, china 2 Key Laboratory of Geodynamic Geodesy of Chinese Academy, Wuhan 43.077, china 3.Key Laboratory of Geospace Environment and Geodesy (Ministry of Education), Wuhan University, Wuhan 43.079, china 4 {3. Key Laboratory of Information Engineering in surveying, mapping and Remote Sensing, Wuhan 43.079, china Department of Geophysics School of Geodesy and Geomatics Wuhan University Wuhan 430079 China

Large earthquakes cause observable changes in the Earth’s gravity field, which have been detected by the Gravity Recovery and Climate Experiment (GRACE). Since most previous studies focus on the detection of near-field gravity effects, this study provides the results from the medium- to far-field gravity changes caused by the 2004 Sumatra-Andaman earthquake that are recorded within GRACE monthly solutions. Utilizing a spherical-earth dislocation model we documented that large-scale signals predominate in the global field of the coseismic gravity changes caused by the earthquake. After removing the near-field effects, the coseismic gravity changes show a negative anomaly feature with an average magnitude of -0.18×10-8 m·s-2 in the region ranging ～40° from the epicenter, which is considered as the 'medium ffield' in this study. From the GRACE data released by center for Space Research from August 2002 to December 2008, we retrieved the large-scale gravity changes smoothed with 3.000 km Gaussian ffilter. The results show that the coseismic gravity changes detected by GRACE in the medium field have an average of (-0.20±0.06)×10-8 m·s-2, which agrees with the model prediction. The detection confirms that GRACE is sensitive to large-scale medium-field coseismic gravitational effects of mega earthquakes, and also validates the spherical-earth dislocation model in the medium field from the perspective of satellite gravimetry.

关键词： GRACE medium-to far-field coseismic gravity change 2004 Sumatra-Andaman earthquake spherical-Earth dislocation model

Radiometric cross-calibration of the CBERS-02 CCD camera with the TERRA MODIS

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Science china(Technological Sciences) 2005年第S2期48卷 44-60页

作者： LI Xiaoying1,2,3. GU Xingfa1,3.4, MIN Xiangjun5, YU Tao1,3. FU Qiaoyan5, ZHANG Yong1,2,3.& LI Xiaowen1,3.1. state Key Laboratory of Remote Sensing Science, Jointly Sponsored by the Institute of Remote Sensing applications of Chinese Academy of Sciences and Beijing Normal University, Beijing 100101, china 2. Graduate University of Chinese Academy of Sciences, Beijing 10003., china 3. The center for National Spaceborne Demonstration, Beijing 100101, china 4. Institut National de la Recherche Agronomique, Climat Sol Environnement, 84914 Avignon, France 5. china center for Resource satellite Data and application, Beijing 10083., china state Key Laboratory of Remote Sensing Science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing 100101 China

For the application of the CCD camera, the most important payload on CBERS-02, the key is to provide long-term stable radiometric calibration coefficients. Although the vicarious calibration had been proved successful, it had its limitations such as test site requirement and unsuitable for historical data. Cross-calibration is one of the alternative methods, but it needs synchro surface spectrum to achieve spectral band matching factors. Our effort is to probe the influences on these factors. Simulations with a lot of surface spectrum showed that the factors changed with the viewing geometry, atmospheric condition and surface targets. However, simulating with the same viewing geometry and atmospheric condition, the spectral band matching factors of the same or similar surface targets’ spectrum acquired from different dates and different places would like to be consistent to each other within 1%―5%. Thus, the synchro measurement data can be substituted by the same or similar target from other source. Based on this method, using the MODIS as the reference, the cross-calibration was performed for CCD camera. The research demonstrated that the traditional method with single calibration site was inappropriate for CCD camera, since the offsets for its four spectral bands were not zeros. With four calibration sites, these offsets were obtained. And the camera was detected to degrade with dates based on four times of cross-calibrations.

关键词： CBERS-02 CCD camera cross-calibration the spectral band matching factors.

Comparison of the influence factors on NDVI for CCD camera and WFI imager on CBERS-02

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Science china(Technological Sciences) 2005年第S2期48卷 100-115页

作者： YU Tao1,3. LI Xiaoying1,2,3. ZHANG Yong1,2,3. ZHAO Feng1,2,3. GU Xingfa1,3.4, ZHU Li1,2,3. WANG Pengxin5 & MIN Xiangjun6 1. state Key Laboratory of Remote Sensing Science Institute of Remote Sensing application, CAS, Bei- jing 100101, china 2. Graduate University of Chinese Academy of Sciences, Beijing 10003., china 3. The center for National Spaceborne Demonstration, Beijing 100101, china 4. Institut National de la Recherche Agronomique, Climat Sol Environnement, 84914 Avignon, France 5. College of Information and Electrical Engineering, china Agricultural University, Beijing 100083. china 6. china center for Resource satellite Data and application, Beijing 10083., china state Key Laboratory of Remote Sensing Science Institute of Remote Sensing application CAS Beijing 100101 China

CCD and WFI are payloads in the visible light and near infrared bands on CBERS satellites and they have not been applied widely, especially WFI. This article mainly probes into the potential of these two sensors’ application in the vegetation monitoring and analyses the influences of radiometric calibration, atmosphere conditions and sun-observing geometry, etc. on NDVI obtained from these two sensors respectively. In addition it analyses the effect of the spectral response difference of red and near infrared spectral bands in CCD and WFI sensors on NDVI. Results indicate that radiometric calibration is the most important factor on NDVI, which cannot be applied to vegetation monitoring without radiometric calibration. Results also demonstrate that near surface NDVI is different greatly from that of TOA which change with atmosphere conditions. The study shows that NDVI is also affected by the non-lambertian character of surface and the change of the atmospheric path with the observing geometry. And NDVI of WFI is higher than that of CCD. They are very different because of their spectral difference, but they have a good linear relevant relationship.

关键词： CCD WFI NDVI LAI.

Study on the relative radiometric correction of CBERS satellite CCD image

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Science china(Technological Sciences) 2005年第S2期48卷 12-28页

作者： GUO Jianning, YU Jin, ZENG Yong, XU Jianyan, PAN Zhiqiang & HOU Minghui china center for Resource satellite Data and {3., Beijing 10083., china china center for Resource satellite Data and {3.

The main payload on CBERS-01/02 of china-Brazil Earth Resources satellite (CBERS) is a push-broom CCD camera with moderate spatial and radiant resolution. Because at lab the data for calibration at satellite assembly stage were unable to be collected, and also because the onboard calibrator after launch was in a different {3. from imaging, the calibration of CCD image got a series of difficulties involved. In practice, two methods are used in the processing on the ground station: One is extracting calibration data by statistics from the image itself, and the other is the method of histogram match. It was proved that the latter can calibrate the image much better, because it can remove the effect of unstable response of the camera largely and also can overcome the nonlinearity of the camera basically by using Look-Up Table (LUT) calculated from histogram statistics of different temporal images. Considering the problems of CBERS-01, a lot of calibration tests were done before the launch of CBERS-02, in which a set of lab coefficients for relative calibration was formulated after the data collection by using integration-hemisphere in the stage of satellite assembly test. During the on-orbit test, it was found that the calibration result from such coefficients was not satisfying, especially there being response difference between 3.detector arrays, which was attributed to the unstable dark currents of the CCD camera. This paper comes up with a statistic method to remove such response difference. In this method the middle detector array was used as reference to find the response differences of adjacent similar features between these arrays and it was proved to have a broad adaptability.

关键词： CBERS satellite CCD camera relative radiometric calibration relative radiometric correction assembly test.

Ocean color products retrieval and validation around china coast with MODIS

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Acta Oceanologica Sinica 2010年第4期29卷 21-27页

作者： SUN Lingt GUO Maohua WANG Xiaomei Key Laboratory of Radiometric Calibration and Validation for Environmental satellites China Meteorological Administration （LRCVES/CMA） National Satellite Meteorological Center China Meteorological Administration Beijing 100081 China National satellite Ocean application Service State Oceanic Administration Beijing 100081 China

Waters along china coast are very turbid with high concentrations of suspended sediment nearly all the time,especially at the Hangzhou Bay,the Changjiang （Yangtze） River Estuary and the shoal along Jiangsu *** these turbid and optically complex waters,the standard MODIS ocean color products tend to have invalid *** the water-leaving radiances in the near-infrared （NIR） are significant resulting from the strong scattering of suspended particles,the standard MODIS atmospheric correction algorithm often gets no results or produces significant *** because of the complex water optical properties,the OC3.model used in the standard MODIS data processing tends to get extremely high chlorophyll-a （Chl-a） *** this paper,we present an atmospheric correction approach using MODIS short wave infrared （SWIR） bands based on the fact that water-leaving radiances are negligible in the SWIR region because of the extreme strong absorption of water even in turbid waters.A regional Chl-a concentration estimation model is also constructed for MODIS from in situ *** algorithms are applied to MODIS Aqua data processing in the china coastal *** situ data collected in the Yellow Sea and the East china Sea in spring and autumn,2003.are used to validate the *** good results have been *** is noted that water-leaving reflectance in the NIR bands are significant in waters along the china coast with high sediment *** satellite derived and in-situ reflectance spectra can match in the turbid waters along china coast,and there is relatively good linear relationship between satellite derived and in-situ *** RMSE value of Rrs（λ） is 0.003. sr ？1 for all the nine ocean color bands （412 to 869 nm）.The satellite-derived Chl-a value is in the reasonable range and the root mean square percentage difference is 46.1%.

关键词： ocean color atmospheric correction chlorophyll-a MODIS china coastal region validation