分类: 地球科学 >> 地质学 提交时间: 2018-04-04 合作期刊: 《古脊椎动物学报》
摘要: Recent fieldwork at Pleistocene cave sites in the Chongzuo area in Guangxi Zhuang Autonomous Region has yielded 33 isolated teeth of fossil hylobatids. Comparisons indicate that the teeth can all be referred to a single species of Nomascus, but the material is insufficient to assign it to a particular species. The molars are slightly larger on average than those of extant species of Nomascus, but unlike contemporary great apes from the Pleistocene of southern China, the hylobatids do not seem to have undergone a change in dental size through time. Nomascus is not present in the Chongzuo area today, but historical records indicate that the genus may have been widely distributed across southern China in the recent past.
分类: 地球科学 >> 空间物理学 提交时间: 2017-03-10
摘要: Target brightness temperature maps can be used in geostationary interferometric microwave sounder (GIMS) system simulation. System simulation with accurate target brightness temperature maps can evaluate system performance in near real case and thus help adjust design parameters for the sensor before it is finally put into use. In this paper, method of simulating target brightness temperature using Weather Research and Forecasting Model and Radiative Transfer for TOVS (RTTOV) has been discussed. Target brightness temperature simulation results at oxygen absorption band and water-vapor absorption band have been presented. Some preliminary analyses of simulated brightness temperature for GIMS' observation have also been given.
分类: 地球科学 >> 空间物理学 提交时间: 2017-03-10
摘要: Brightness temperature change of observation target in one imaging period will introduce image blur to the retrieved image of geostationary interferometric microwave sounder (GIMS), which uses rotating circular array to realize time-sharing sampling other than snap-shot to reduce system complexity but meanwhile resulting in a relatively long imaging period. In this paper, an interpolation method utilizing time sequence of visibilities collected by time-sharing sampling is presented. The method is verified through a simulation system that simulates GIMS's observation process in viewing a series of near real case brightness temperature maps modeled by FNL/WRF/RTTOV method. Results show that the interpolation method can de-blur the image and reduce imaging error to the degree of snap-shot imaging. �2016 IEEE.
分类: 地球科学 >> 空间物理学 提交时间: 2017-03-10
摘要: Imaging period is an important consideration to geostationary interferometric microwave sounder (GIMS) when mapping fast changing target such as typhoon. GIMS simulation system with near real case observation target can evaluate system performance in different system configurations and thus help determine the optimal imaging period. In this paper, GIMS simulation system using MATLAB and near real case observation modeled by FNL/WRF/RTTOV method has been used to analyze the effect of imaging period on image quality. System simulation results for each frequency channel will be presented and analyses of imaging period's effect on image quality will also be given. �2016 IEEE.
分类: 地球科学 >> 空间物理学 提交时间: 2017-03-10
摘要: In this paper, an SMMW interferometric radiometer concept is demonstrated by a two-element interferometer with dedicated high accuracy SMMW devices. Point-source calibration method is introduced in order to reduce instrument errors. Interference fringes and point target images are presented by this SMMW interferometer. The linear phase error of the interference fringes is less than 2�and the angular resolution is better than 0.57� The measured performance characteristics of the two-element interferometer are consistent with the theoretical analysis. This interferometer demonstrates a new method for passive SMMW remote sensing. �2016, Science Press. All right reserved.
分类: 地球科学 >> 空间物理学 提交时间: 2016-05-03
摘要: Target brightness temperature maps can be used in geostationary interferometric microwave sounder (GIMS) system simulation. System simulation with accurate target brightness temperature maps can evaluate system performance in near real case and thus help adjust design parameters for the sensor before it is finally put into use. In this paper, method of simulating target brightness temperature using Weather Research and Forecasting Model and Radiative Transfer for TOVS (RTTOV) has been discussed. Target brightness temperature simulation results at oxygen absorption band and water-vapor absorption band have been presented. Some preliminary analyses of simulated brightness temperature for GIMS' observation have also been given.