Time filter

Source Type

Ye J.,University of South China | Ye J.,Chengdu University of Technology | Zhu H.-T.,Environmental Satellite Application Center | Guo N.,Chengdu University of Technology | Guo N.,CAS Institute of Remote Sensing
Journal of Chengdu University of Technology (Science and Technology Edition) | Year: 2015

The exploitation process of the Jiama copper polymetallic deposit in Tibet of China has involved numerous protection problems of the land use / land cover. The authors of this paper adopt IKONOS HD image to calculate the land use / land cover and landscape pattern index under the support of Geographic Information System and the theory of landscape ecology. Based on this, they analyze and evaluate the present situation of the land use in this area. The final results indicate that there are four main factors to influence the landscape pattern of this area. First, the grassland is the landscape matrix of the study area and has the greatest effect on the whole landscape pattern of the Jiama mining area; secondly, the shrub forestland has the largest fragmentation, and the majority of the landscape patches are set in the grassland types; thirdly, the fragmentation of the bare rock types is minimum, and most of the landscape patches are concentrated; and fourthly, the land used for construction, cultivated land and water areas have the lowest effect on the whole landscape of the Jiama mining area. The authors suggest that people have to lay equal stress on the exploitation and management during exploiting the mining area and improve the soil matrix and protect the water resources in the mine reclamation, plant mainly grass and inlay the shrub land into the grassland reasonably in order to ensure the rational exploitation and utilization of the green mine and the objective of protecting the delicate ecological environment in Tibet.

Wang Z.-T.,Environmental Satellite Application Center | Wang Z.-F.,CAS Institute of Remote Sensing Applications | Wang Z.-F.,University of Chinese Academy of Sciences | Li Q.,Environmental Satellite Application Center | And 3 more authors.
Zhongguo Huanjing Kexue/China Environmental Science | Year: 2011

AOD (aerosol optical depth) over land surfaces was retrieved by DDV (dark dense vegetation) method, then based on the vertical and RH (relative humidity) correction, the model of PM10 retrieval was established. In order to validate the model, PM10 in the Beijing-Tianjin-Tangshan area was retrieved from May to August, 2009, and was compared against the ground-based measurements provided by China National Environmental Monitoring Centre. The results showed that, HJ-1 data can meet the requirement of weekly monitoring of PM10, and the correlation coefficient between the retrieved and measured PM10 was 0.58. However, the HJ-1 retrieved PM10 had a negative bias from the ground-based measurements, and further improvement would be conducted to improve the retrieving accuracy.

Ma P.,Environmental Satellite Application Center | Chen L.,CAS Institute of Remote Sensing | Wang Z.,Environmental Satellite Application Center | Zhao S.,Environmental Satellite Application Center | And 3 more authors.
IEEE Transactions on Geoscience and Remote Sensing | Year: 2016

This paper presents an algorithm for the retrieval of ozone profiles from the Cross-track Infrared Sounder (CrIS) aboard the Suomi National Polar-orbiting Partnership satellite using a nonlinear optimal estimation method. The issue of channel selection is discussed. Based on a sensitivity analysis, we selected a spectral range of 990-1070 cm-1 for the ozone profile retrievals. Compared with ERA-Interim ozone profiles and eigenvector regression method profiles, the ozone climatology profile is better able to construct the a priori state. The retrieved CrIS profiles are in good agreement with smoothed high-vertical-resolution ozonesonde profiles. An analysis of the information content of the CrIS retrievals demonstrates that the CrIS measurements can provide useful information for capturing the spatial and temporal variations in ozone and are insensitive to ozone below 400 hPa. An error analysis revealed that smoothing error represents the main error source for the retrieved CrIS ozone profiles. © 2016 IEEE.

Wang Z.-T.,Environmental Satellite Application Center | Li Q.,Environmental Satellite Application Center | Chen L.-F.,CAS Institute of Remote Sensing Applications | Wang Z.-F.,Environmental Satellite Application Center | And 2 more authors.
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2011

Generally, aerosols over land are composed of fine and coarse aerosols, which have different optical properties. How to derive the fine mode and coarse mode aerosols from satellite observations is an important issue in the aerosol retrieving. In the present paper, information of aerosol models (including refractive index and size distribution function) was retrieved from the ground-based measurement of the AERONET/PHOTONS site in Beijing. The retrievals indicate that, aerosols over Beijing have a bi-model distribution, and the optical properties of fine and coarse aerosols are distinct. Based on the dark dense vegetation (DDV) method, optical depth of the fine, coarse and total aerosols were derived from MODIS data over Beijing area in 2007. The validation of these satellite retrievals shows that from MODIS data, the optical depth of fine and total aerosols can be retrieved well (with correlation coefficients greater than 0.8), and so can the Angstrom exponent (having a correlation coefficient of 0.517). However, relatively poor results were obtained when retrieving the optical depth of coarse aerosols.

Ma P.-F.,CAS Institute of Remote Sensing | Ma P.-F.,Environmental Satellite Application Center | Ma P.-F.,State Environmental Protection Key Laboratory of Satellite Remote Sensing | Chen L.-F.,CAS Institute of Remote Sensing | And 9 more authors.
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2015

Nitrous Oxide is a very important greenhouse gases and ozone-depleting substances. Due to the limited observations, there are still many uncertainties to quantitativelydescribe therole of nitrous oxide played in both cases. We can retrieve the methane and carbon dioxide gas using thermal infrared satellite data AIRS, but it is rarely for the nitrous oxide retrieval. Therefore, this paper retrieves nitrous oxideprofiles from the AIRS data with anOptimal Estimate Method for the first time in China. The issue of the a priori and channelselection is discussed. Comparison of the retrieved AIRS profiles with HIPPOprofiles show the retrieved profiles are in good agreement with the smoothed HIPPO profiles, and a notable improvementin this algorithmthan the eigenvector regression algorithm. For pressures between 300 and 900 hPa, we got the most accurate profiles and the relative erroris only 0.1%, which is consistent with the jacobian peaks of the selected channels. ©, 2015, Science Press. All right reserved.

Discover hidden collaborations