Research On Fourier Spectral Detect Based On Focal Plane And Interferogram Data Processing Technology

Present meteorological satellites obtain the vertical information of atmospheric temperature and humidity by measuring the contour of atmospheric temperature and humidity,which improves the accuracy of weather forecast.The onboard infrared Fourier spectrometer has the ability of hyperspectral resolution detection and atmospheric vertical detection,and can accurately obtain the atmospheric temperature and humidity profile,which is one of the research hotspots in the field of meteorology.At the 17 th World Meteorological Congress,the WMO committee determined the long-term development plan of the global integrated observation system in 2040,which put forward further requirements for high-resolution Regional Numerical Weather Forecast and effective guidance of ultra short-term forecast,and accurately monitor the intensity and path changes of typhoon and strong convective system in time.This requires the onboard Fourier spectrometer to speed up the observation frequency.In order to achieve the requirement of faster observation frequency,the onboard Fourier spectrometer needs to be equipped with a larger array of infrared focal plane detectors and improve the acquisition speed of interferograms,and realize the effective detection of long wave infrared interference signals.This increases the load of data acquisition,transmission and processing,and improves the difficulty of interference signal acquisition.In order to obtain high-quality infrared interference data with a larger focal plane detector,it is necessary to design and build an interference information acquisition system under the conditions of equal optical path difference,high frame rate and external trigger sampling.In this paper,the information acquisition technology schemes of domestic and European satellite borne infrared Fourier spectrometer are investigated.The working principle of the Fourier spectrometer and the acquisition of infrared interference signal are described The methods are analyzed comprehensively and completely;the acquisition and data transmission of light interference signal under the external trigger of high frame rate are studied in depth;the influence of multi system coupling and mechanical vibration on the noise performance of the system is analyzed;the noise-link model of infrared interference signal acquisition is established;two sets of interference signals are built by using photovoltaic Hg Cd Te focal plane detector acquisition system,respectively in the infrared medium band and long band acquisition of interference data;a test platform is built to achieve the quantitative calculation of noise equivalent spectral radiation,complete the performance evaluation of the infrared interference system.In this paper,the acquisition and data transmission of ultra-high sampling rate weak interference signal under external triggering are studied,and the technical scheme is put forward;the influence of coupling between multi-systems and mechanical vibration on system noise performance is analyzed.At the same time,in order to evaluate the performance of infrared interference system completely,the noise-link model of infrared interference signal is established.The quantitative calculation of noise equivalent spectral radiation is realized to measure system noise.A set of evaluation system for infrared interference signal acquisition system is constructed.Through the optimization of hardware and software,the interference of digital and analog signals in the system is further suppressed,and the quality of interference data is improved under the condition of uneven response rate of detector.A real-time cloud detection scheme is proposed to solve the problem that thick clouds hinder the detection of space borne Fourier spectrometer,and the scheme is verified by zynq-7020.By analyzing and processing the acquired infrared interference data,we found and solved the problems of the translation of the interferogram and the uneven acquisition of the interference information caused by the unstable acquisition.For the middle wave band signal with band range of 4.44 um to 6.06 um,the system can obtain all interference information of 1024 pixels stably and completely.At last,the conception and Prospect of the electronic information acquisition method of the space borne infrared Fourier spectrometer with larger array are put forward.