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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 {4. for National Spaceborne Demonstration, beijing 100101, China 4. Institut National de la Recherche Agronomique, Climat Sol Environnement, 84.14.Avignon, France 5. China {4. for resource satellite {13. and application, beijing 10083., China 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 100101 Beijing China 2. Graduate University of Chinese Academy of Sciences 100039 Beijing China 3. The center for National Spaceborne Demonstration 100101 Beijing China 4. Institut National de la Recherche Agronomique Climat Sol Environnement 84914 Avignon France 5. China center for resource satellite {3. and {4. 100830 Beijing 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.

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. State Key Laboratory of Remote Sensing Science, beijing 100010, China 3. China {4. for resource satellite data and applications (CRESDA), beijing 100083. China 1. National satellite Ocean application Service (NSOAS) 100081 Beijing China 2. State Key Laboratory of Remote Sensing Science 100010 Beijing China 3. China center for resource satellite {3. and {4.s (CRESDA) 100083 Beijing 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

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 {3. and {4., beijing 10083., China China Ctr resource satellite data & Applicat Beijing 100830 Peoples R China

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 state 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.

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 {3. for National Spaceborne Demonstration, beijing 100101, China 4. Institut National de la Recherche Agronomique, Climat Sol Environnement, 84.14.Avignon, France 5. College of Information and Electrical Engineering, China Agricultural University, beijing 100083. China 6. China {3. for resource satellite data and application, beijing 10083., China 1. State Key Laboratory of Remote Sensing Science Institute of Remote Sensing Application CAS 100101 Beijing China 2. The center for National Spaceborne Demonstration 100101 Beijing China 3. Graduate University of Chinese Academy of Sciences 100039 Beijing China 4. Institut National de la Recherche Agronomique Climat Sol Environnent 84914 Avignon France 5. College of Information and Electrical Engineering China Agricultural University 100083 Beijing China 6. China center for resource satellite {3. and {4. 100830 Beijing 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.

In flight MTF monitoring and compensation for CCD camera on CBERS-02

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Science China(Technological Sciences) 2005年第S2期48卷 29-43页

作者： GU Xingfa1,2,3. LI Xiaoying1,2,4. MIN Xiangjun5, YU Tao1,2, SUN Jijuan5, ZENG Yong1,2,4. XU Hua1,2 & GUO Ding2,6 1. State Key Laboratory of Remote Sensing Science, Jointly Sponsored by the Institute of Remote Sensing applications of Chinese Academy of Sciences and {3. Normal University, {3. 100101, China 2. The {3. for National Spaceborne Demonstration, {3. 100101, China 3. Institut National de la Recherche Agronomique, Climat Sol Environnement, 84.14.Avignon, France 4. Graduate University of Chinese Academy of Sciences, {3. 10003., China 5. China {3. for resource {13. data and application, beijing 10083., China 6. University of Electronic Science and Technology of China, Chengdu 610054. 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 100101 Beijing China The center for National Spaceborne Demonstration 100101 Beijing China Institut National de la Recherche Agronomique Climat Sol Environnement 84914 Avignon France Graduate University of Chinese Academy of Sciences 100039 Beijing China China center for resource satellite {3. and {4. 100830 Beijing China University of Electronic Science and Technology of China 610054 Chengdu China

In this article, the approach of simulating ideal tarp scene was proposed to determine the MTF for CCD camera on CBERS-02. The MTF acquired from this technique was compared to those from some common methods. MTFs achieved from different approaches were employed to compensate the CCD images based on three restoration algorithms: the iterative method, the Wiener filter and the modified inverse filter (MIF). The two-dimensional MTF was established with the value at frequency 0.5 for 4.° directional MTF as the value at its four corners. This article addressed the variations of the restored CCD images with different techniques of constructing two-dimensional MTF, restoring algorithms and determining the in-flight MTFs. Results showed images restored with the MTF determined from the technique of simulating ideal tarp scene represent the real scene best. And the restoration technique based on the MIF would produce better restored images than the other two techniques. This research also demonstrated that the two-dimensional MTF used for restoration should be interpolated under the control of the MTF for 4.° axis, rather than by multiplying the cross-orbit MTF with along-orbit MTF.

关键词： CBERS-02 CCD MTF the technique of simulating ideal tarp scene.

Integrated precise orbit determination of Shenzhou IV unmanned spacecraft

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Science China(Technological Sciences) 2004年第5期47卷 518-525页

作者： L Congmin1,2, GU Yidong3. LIN Baojun3.& GUO Jiong3.1. center for Space Science and Applied Research, Chinese Academy of Sciences, beijing 100080, China 2. Graduate School of the Chinese Academy of Sciences, beijing 10003., China 3. General Establishment of Space Science and {3., Chinese Academy of Sciences, beijing 100080, China Correspondence should be addressed to L Congmin 1. center for Space Science and Applied Research Chinese Academy of Sciences 100080 Beijing China 2. Graduate School of the Chinese Academy of Sciences 100039 Beijing China 3. General Establishment of Space Science and application Chinese Academy of Sciences 100080 Beijing China

Considering the characteristic orbit of Shenzhou IV spacecraft and the advantages and disadvantages of several types of domestic orbit measurements, a scheme of IPOD is determined, which uses GPS, SLR and USB observation data jointly plus precise ionosphere corrections to GPS observation data. IPOD system and mathematic models of OD are introduced. The results of different joint OD are analyzed using true observation data, and show that radial accuracy is better than 2 m.

关键词： Shenzhou IV unmanned spacecraft integrated precise orbit determination GPS SLR USB.

Study on attribute characterization for reservoir dynamic monitoring by seismic

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Science China Earth Sciences 2008年第S2期51卷 218-225页

作者： CHEN XiaoHong1,3.LI JingYe2,3.& ZHAO Wei4.1 Key Lab of Geophysical Exploration of CNPC,China Petroleum University,beijing 10224.,China 2 Basin & Reservoir Research {3.,China Petroleum University,beijing 10224.,China 3.State Key Laboratory of Petroleum {3. and Prospecting,China University of Petroleum,beijing 10224.,China 4.Research {3. of CNOOC,beijing 100027,China 1. Key Lab of Geophysical Exploration of CNPC China Petroleum University Beijing 102249 China 3. State Key Laboratory of Petroleum resource and Prospecting China University of Petroleum Beijing 102249 China 2. Basin & Reservoir Research center China Petroleum University Beijing 102249 China 4. Research center of CNOOC Beijing 100027 China

Study on characterizing reservoir parameters dynamic variations by time-lapse seismic attributes is the theoretical basis for effectively distinguishing reservoir parameters variations and conducting time-lapse seismic interpretation,and it is also a key step for time-lapse seismic application in real oil fields. Based on the rock physical model of unconsolidated sandstone,the different effects of oil saturation and effective pressure variations on seismic P-wave and S-wave velocities are calculated and analyzed. Using numerical simulation on decoupled wave equations,the responses of seismic amplitude with different offsets to reservoir oil saturation variations are analyzed,pre-stack time-lapse seismic attributes differences for oil saturation and effective pressure variations of P-P wave and P-S converted wave are calculated,and time-lapse seismic AVO (Amplitude Versus Offset) response rules of P-P wave and P-S converted wave to effective pressure and oil saturation variations are compared. The theoretical modeling study shows that it is feasible to distinguish different reservoir parameters dynamic variations by pre-stack time-lapse seismic information,including pre-stack time-lapse seismic attributes and AVO information,which has great potential in improving time-lapse seismic interpreta-tion precision. It also shows that the time-lapse seismic response mechanism study on objective oil fields is especially important in establishing effective time-lapse seismic data process and interpreta-tion scheme.

关键词： time-lapse seismic dynamic monitoring rock physical model pre-stack attribute Amplitude Versus Offset (AVO)

Study of thin cloud removal method for CBERS-02 image

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Science China(Technological Sciences) 2005年第S2期48卷 91-99页

作者： MA Jianwen1, GU Xingfa1, FENG Chun2 & GUO Jianning2 1. Institute of Remote Sensing application, Chinese Academy of Sciences, beijing 100101, China 2. China center for {3. {4. data and applications, beijing 100073. China 1. Institute of Remote Sensing application Chinese Academy of Sciences 100101 Beijing China 2. China center for resource satellite {3. and {4.s 100073 Beijing China

The China Brazil Earth resources satellite (CBERS) ended the dependence on foreign satellites. Along with the series of CBERS and the enhancement of satellite {4.s, it is necessary to search correlative data processing methods. Because cloud appears in the atmosphere, an image with clear sky conditions is often hard to obtain. How to remove cloud is an important sector of increasing image quality. An improved homomorphism filtering method is adopted to remove thin cloud qualitatively at first, and all bands are selected to classify pixels. Based on the fact that visible band images contain more aerosol effects than infrared bands, visible bands are used to determine clear or hazy regions and the reflectances of different surface classes in clear regions are calculated. At last the mean reflectance of the same classes in clear and hazy regions is matched to remove cloud. The image visual effect is improved; meanwhile, the ground reflectance is retrieved to meet the needs of remote sensing quantification.

关键词： CBERS-02 cloud removal surface reflectance mean reflectance matching.

Orbit determination for geostationary satellites with the combination of transfer ranging and pseudorange data

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Science China(Physics,Mechanics & Astronomy) 2010年第9期53卷 1746-1754页

作者： GUO Rui1,2,3.4.HU XiaoGong2,4.LIU Li1,WU XiaoLi1,HUANG Yong2,4.& HE Feng1 1 {3. Global Information application and Development center,{3. 100094.China 2 Shanghai Astronomical Observatory,Chinese Academy of Sciences,Shanghai 20003.,China 3.Graduate University of Chinese Academy of Sciences,{3. 10004.,China 4.Space Navigation and Positioning Technology,Laboratory of Shanghai Municipal,Shanghai 20003.,China 1. beijing Global Information application and Development center Beijing 100094 China2. Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai 200030 China3. Graduate University of Chinese Academy of Sciences Beijing 100049 China4. Space Navigation and Positioning Technology Laboratory of Shanghai Municipal Shanghai 200030 China

Geostationary satellites(GEOs) play a significant role in the regional satellite navigation *** experiments show that the clock corrections could be mitigated through a single strategy or double differencing strategies for a navigation constellation,but for the mode of individual GEO orbit determination,high precision orbit and clock correction could not be obtained in the orbit determination based on the pseudorange data.A new GEO combined precise orbit determination(POD) strategy is studied in this paper,which combines pseudorange data and C-band transfer ranging *** strategy overcomes the deficiency of C-band transfer ranging caused by limited stations and tracking time *** the combination of transfer ranging and pseudorange data,clock corrections between the GEO and the stations can be estimated simultaneously along with orbital parameters,maintaining self-consistency between the satellite ephemeris and clock correction *** error covariance analysis is conducted to illuminate the contributions from the transfer ranging data and the psudoranging *** data collected for a Chinese GEO satellite with 3.C-band transfer ranging stations and 4.L-band pseudorange tracking stations,POD experiments indicate that a meter-level accuracy is *** root-mean-square(RMS) of the post-fit C-band ranging data is about 0.203.m,and the RMS of the post-fit pseudorange is 0.4.8 *** component errors of the POD experiments are independently evaluated with the satellite laser ranging(SLR) data from a station in beijing,with the residual RMS of 0.076 *** SLR evaluation also suggests that for 2-h orbital predication,the predicted radial error is about 0.4.4.m,and the clock correction error is about 1.3. *** for the combination of one C-band transfer ranging station and 4.pseudorange stations,POD is able to achieve a reasonable accuracy with the radial error of 0.280 m and the 2-h predicted radial error of 0.888 *** syn

关键词： satellite navigation precise orbit determination pseudorange equipment ranging delay GEO SLR