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Cheng T.H.,CAS Institute of Remote Sensing Applications | Cheng T.H.,University of Chinese Academy of Sciences | Cheng T.H.,Demonstration Center for Spaceborne Remote Sensing | Gu X.F.,CAS Institute of Remote Sensing Applications | And 5 more authors.
Journal of Quantitative Spectroscopy and Radiative Transfer | Year: 2010

In this paper, we investigate the capability of multi-angle TOA reflectance and polarized reflectance for the retrieval of aerosol properties including aerosol mode (fine mode and coarse mode), aerosol shape (sphere and non-spherical), and aerosol optical thickness. Single-scattering parameters and phase-matrix elements were computed for randomly oriented non-spherical aerosol particles. Sensitivity indices were introduced to quantify the sensitivity of the TOA total reflectance and polarized reflectance to aerosol parameters. Finally, on the basis of the sensitivity study, this paper presents a conceptual approach toward the remote sensing of non-spherical aerosol three parameters (aerosol mode, aerosol shape, and aerosol optical thickness) using the TOA total reflectance and TOA polarized reflectance for the 0.865 μm spectral bands measured at multiple viewing angles. © 2009 Elsevier Ltd. All rights reserved. Source


Gu X.,CAS Institute of Remote Sensing Applications | Gu X.,Demonstration Center for Spaceborne Remote Sensing | Yanli Q.,CAS Anhui Institute of Optics and Fine Mechanics | Wang J.,CAS Institute of Remote Sensing Applications | And 5 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

A new airborne Directional Polarimetric Camera (DPC) was developed to retrieve aerosol optical and microphysical properties over urban with high spatial resolution, dealing with the apportionment of sources and controls on air quality in the city. The instrument is a Polarization and Directionality of Earth's Reflectance (POLDER) type polarized camera with significant improvement in the space resolution realizing monitoring aerosol emission and absorption sources like megacities in China. This paper describes the DPC instrument characteristics, instrument calibration, and the flight experiment in the Delta Peal Region of China. © 2010 Copyright SPIE - The International Society for Optical Engineering. Source


Yuan F.,University of Electronic Science and Technology of China | Yuan F.,CAS Institute of Remote Sensing Applications | Yuan F.,Demonstration Center for Spaceborne Remote Sensing | Gao W.,University of Electronic Science and Technology of China | And 11 more authors.
International Journal of Advancements in Computing Technology | Year: 2012

This paper, referring to technology about storage management systems of massive remote sensing images at home and abroad, proposed a new distributed storage strategy and parallel retrieval mode based on lightweight embedded database files. In the light of demands of storage management systems of massive remote sensing data, the original image data is firstly cut into standard tile data based on the data organization way called Five-layer-Fifteen-level, then tile data is stored in the disk directories of storage nodes by an distributed way, and the metadata of these standard tiles is stored in lightweight embedded database files instead of large-scale relational database in the corresponding storage nodes also by an distributed way. A large number of retrieval efficiency tests were implemented by using this storage program. Retrieval test results indicate that retrieval method based on embedded database files has much higher efficiency than that based on popular large-scale client/server relational database engines or that based on pure file system. The comprehensive program proposed by this paper provides a new strategy for storage and management of remote sensing data facing petabyte level. Source


Guo J.,CAS Institute of Remote Sensing | Guo J.,Demonstration Center for Spaceborne Remote Sensing | Gu X.,CAS Institute of Remote Sensing | Gu X.,Demonstration Center for Spaceborne Remote Sensing | And 6 more authors.
IOP Conference Series: Earth and Environmental Science | Year: 2014

Atmospheric aerosol plays an important role in the climate change though direct and indirect processes. In order to evaluate the effects of aerosols on climate, it is necessary to have a research on their spatial and temporal distributions. Satellite aerosol remote sensing is a developing technology that may provide good temporal sampling and superior spatial coverage to study aerosols. The Moderate Resolution Imaging Spectroradiometer (MODIS) and Multi-angle Imaging Spectroradiometer (MISR) have provided aerosol observations since 2000, with large coverage and high accuracy. However, due to the complex surface, cloud contamination, and aerosol models used in the retrieving process, the uncertainties still exist in current satellite aerosol products. There are several observed differences in comparing the MISR and MODIS AOD data with the AERONET AOD. Combing multiple sensors could reduce uncertainties and improve observational accuracy. The validation results reveal that a better agreement between fusion AOD and AERONET AOD. The results confirm that the fusion AOD values are more accurate than single sensor. We have researched the trend analysis of the aerosol properties over China based on nine-year (2002-2010) fusion data. Compared with trend analysis in Jingjintang and Yangtze River Delta, the accuracy has increased by 5% and 3%, respectively. It is obvious that the increasing trend of the AOD occurred in Yangtze River Delta, where human activities may be the main source of the increasing AOD. Source


Liu L.,CAS Institute of Remote Sensing | Liu L.,University of Chinese Academy of Sciences | Liu L.,Demonstration Center for Spaceborne Remote Sensing | Gu X.,CAS Institute of Remote Sensing | And 12 more authors.
Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering | Year: 2012

The in-flight radiometric calibration for thermal bands of HJ-1B was described using the test site, Qinghai-lake based on the calibration of the thermal-infrared field radiometer CE312. Because of the instability of the onboard calibration, the high temperature point was hard to obtain, the single-point and two-point calibration methods were used to calculate the calibration coefficients respectively. The results were validated by the data of June 29, 2010 at the Dali-lake test site. It shows that the calibration coefficients calculated by the data of Qinghai-lake have high reliability. And the comparison between the methods of single-point calibration and two-point calibration show that the accuracy of two-point calibration method is better than the single-point one. Source

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