风云四号A星(FY-4A)上搭载的干涉式红外探测仪(GIIRS)是首个地球静止轨道上的红外高光谱大气探测仪,它可以提供连续的三维大气温度和水汽的观测,通过追踪水汽的移动可以反演得到不同高度的大气水平风场。本研究利用台风玛丽亚(2018年)期...风云四号A星(FY-4A)上搭载的干涉式红外探测仪(GIIRS)是首个地球静止轨道上的红外高光谱大气探测仪,它可以提供连续的三维大气温度和水汽的观测,通过追踪水汽的移动可以反演得到不同高度的大气水平风场。本研究利用台风玛丽亚(2018年)期间FY-4A加密观测(15分钟间隔)的GIIRS数据开展晴空和部分云区的三维水平风场算法研究,重点研究如何联合同一卫星平台的多光谱成像仪(AGRI)改进GIIRS部分云视场区的三维风场反演结果。利用ERA5独立测试集、CRA40再分析和空投探空数据开展对晴空和云区的三维风场反演结果的检验,基于该个例的反演结果表明:(1)基于GIIRS亮温信息反演得到对流层水平风场,在晴空区均方根误差小于1.5 m s^(-1),方向绝对差基本在15°左右,在部分云视场区,均方根误差为1.5~1.7 m s^(-1),方向绝对差基本在20°左右。与光流法相比,基于GIIRS亮温的直接反演表现出更好的优势,其均方根误差和方向绝对差明显小于光流法的结果。(2)按云量和云顶高度分类后,表现出云量越多、云顶高度越高则RMSE(Root Mean Square Error)越大。在部分云视场区,进一步在反演模型输入中加入来自同平台上成像仪(AGRI)云量和云高信息后,RMSE有所减小,表明更高空间分辨率的AGRI产品可以改进GIIRS部分云覆盖区的风场反演精度。(3)基于GIIRS亮温信息反演的风廓线与CRA40再分析、空投探测风廓线有较好的一致性,表明利用静止卫星红外高光谱大气探测仪观测亮温反演风场的合理性和可行性。展开更多
In the infrared spectrum absorbed type gas concentration sensor,voltage signal obtained from the two-channel thermopile infrared detector TPS2534 is very weak.In order to solve this problem,the authors have establishe...In the infrared spectrum absorbed type gas concentration sensor,voltage signal obtained from the two-channel thermopile infrared detector TPS2534 is very weak.In order to solve this problem,the authors have established the structure of the sensor and designed weak signal detecting circuit of the sensor based on infrared spectrum absorption principle,differential de-noising principle and weak signal detecting principle.The authors have made experiments using CH4 gas.The results show that the circuit can remove noise effectively and detect weak electrical signal obtained from the detector.展开更多
In this work,we simulated 2D infrared spectroscopy(IR)spectroscopy in both transmission geometry and Brewster-angle reflection geometry.Light dispersion and the leakage of s-polarized light are considered in simulatin...In this work,we simulated 2D infrared spectroscopy(IR)spectroscopy in both transmission geometry and Brewster-angle reflection geometry.Light dispersion and the leakage of s-polarized light are considered in simulating the enhancement factor of the reflection mode.Our simulation shows that the dispersion in reflection will only alter the 2D IR lineshape slightly and can be corrected.Leaking spolarized light due to imperfectness of IR polarizers in the reflection geometry may limit the enhancement factor,but such limit is above what a typical experiment can reach.In the current experiment,the enhancement factor is mainly limited by the precision of incident angle,for which ordinary rotation stages are probably not adequate enough.Moreover,traditional energy ratio of pump and probe pulses,which is 9:1,may not be ideal and could be changed to 2:1 in the reflection geometry.Considering all the above factors,the enhancement on the order of 1000 is possible in the current experiment.Nevertheless,near-Brewster angle reflection will enhance both the signal and the noise caused by the signal itself,therefore this method only works if the noise is unrelated to the signal,particularly if the noise is caused by the fluctuation in the probe.It cannot improve the signal to noise ratio when the dominate noise is from the signal itself.The theoretical results here agree reasonably well with published experiment results and pave way for realizing even higher enhancement at nearer-Brewster angle.展开更多
文摘风云四号A星(FY-4A)上搭载的干涉式红外探测仪(GIIRS)是首个地球静止轨道上的红外高光谱大气探测仪,它可以提供连续的三维大气温度和水汽的观测,通过追踪水汽的移动可以反演得到不同高度的大气水平风场。本研究利用台风玛丽亚(2018年)期间FY-4A加密观测(15分钟间隔)的GIIRS数据开展晴空和部分云区的三维水平风场算法研究,重点研究如何联合同一卫星平台的多光谱成像仪(AGRI)改进GIIRS部分云视场区的三维风场反演结果。利用ERA5独立测试集、CRA40再分析和空投探空数据开展对晴空和云区的三维风场反演结果的检验,基于该个例的反演结果表明:(1)基于GIIRS亮温信息反演得到对流层水平风场,在晴空区均方根误差小于1.5 m s^(-1),方向绝对差基本在15°左右,在部分云视场区,均方根误差为1.5~1.7 m s^(-1),方向绝对差基本在20°左右。与光流法相比,基于GIIRS亮温的直接反演表现出更好的优势,其均方根误差和方向绝对差明显小于光流法的结果。(2)按云量和云顶高度分类后,表现出云量越多、云顶高度越高则RMSE(Root Mean Square Error)越大。在部分云视场区,进一步在反演模型输入中加入来自同平台上成像仪(AGRI)云量和云高信息后,RMSE有所减小,表明更高空间分辨率的AGRI产品可以改进GIIRS部分云覆盖区的风场反演精度。(3)基于GIIRS亮温信息反演的风廓线与CRA40再分析、空投探测风廓线有较好的一致性,表明利用静止卫星红外高光谱大气探测仪观测亮温反演风场的合理性和可行性。
文摘In the infrared spectrum absorbed type gas concentration sensor,voltage signal obtained from the two-channel thermopile infrared detector TPS2534 is very weak.In order to solve this problem,the authors have established the structure of the sensor and designed weak signal detecting circuit of the sensor based on infrared spectrum absorption principle,differential de-noising principle and weak signal detecting principle.The authors have made experiments using CH4 gas.The results show that the circuit can remove noise effectively and detect weak electrical signal obtained from the detector.
基金supported by the National Natural Science Foundation of China(No.21973102,No.21573243,and No.21327802)。
文摘In this work,we simulated 2D infrared spectroscopy(IR)spectroscopy in both transmission geometry and Brewster-angle reflection geometry.Light dispersion and the leakage of s-polarized light are considered in simulating the enhancement factor of the reflection mode.Our simulation shows that the dispersion in reflection will only alter the 2D IR lineshape slightly and can be corrected.Leaking spolarized light due to imperfectness of IR polarizers in the reflection geometry may limit the enhancement factor,but such limit is above what a typical experiment can reach.In the current experiment,the enhancement factor is mainly limited by the precision of incident angle,for which ordinary rotation stages are probably not adequate enough.Moreover,traditional energy ratio of pump and probe pulses,which is 9:1,may not be ideal and could be changed to 2:1 in the reflection geometry.Considering all the above factors,the enhancement on the order of 1000 is possible in the current experiment.Nevertheless,near-Brewster angle reflection will enhance both the signal and the noise caused by the signal itself,therefore this method only works if the noise is unrelated to the signal,particularly if the noise is caused by the fluctuation in the probe.It cannot improve the signal to noise ratio when the dominate noise is from the signal itself.The theoretical results here agree reasonably well with published experiment results and pave way for realizing even higher enhancement at nearer-Brewster angle.
