Research On Real-time Data Processing Techniques For Infrared Interferometer

Fourier Transform Spectrometer(FTS) is a potential technology for satelliteremote sensing and Atmospheric Sounding because of its high spectralresolution,multi-channels,broad spectral coverage, and high throughput.On-boardInterferometer provides high resolution infrared spectra of the Earth atmospherewith which the temperature、humidity and water vapor profiles of the Earthatmosphere,trace gases,atmospheric constituents, air pollution and greenhouse gasescan be obtained,used for weather、climate change and human activity、atmosphericsciences research. Physical measurement of the FTS is not directly a spectrum andthat a lot of mathematical transformations are necessary to obtain this physical data.The instrument data production rate is to high to be downlinked directly.In order toreach the allocated downlink data transmission rate,it was necessary to implementon board data processing. This dissertation research on Fourier Transform Infraredspectrometry real-time data processing techniques.First,principle of FTS and on-board date processing development are given.Typical on-board data processing systems of spaceborne interferometer areinvestigated.Theory of transform the raw interferogram to calibrated spectra areinvestigated.Then,the scheme of data processing based on spectarl recovery andprovision of useful spectra is put forward.Hardware platform of on-board processing are investigated.Considering largedata volume、regulation algorithm fabric、real-time needed of on-board dataprocessing,FPGAs such as Xilinx-5series that including DSP blocks therebyprovding many resources to meet computationally-intensive data processing need.SoFPGA is choose for hardware implement. An method of FPGA processing systemradiation hardening by design and software is proposal.This dissertation introduced a flowchart of raw interferogram processing,including on board real-time processing chain and post-ground processing chain.Thearchitecture of real-time processing chain and relative algorithm is given,includingspikes detection/correction、non-linearity correction、NZPD、FFT、phase correction、spectra coding、 Interferograms co-added.The principle、 mathematics model、simulation results with maltlab of these algorithms is given detail in this paper.This paper presents processing system hardware implementation,including processing card design,algorithm implementation with FPGA，PCIE data interfacemodule based on FPGA with corresponding software.The hardware implementationresult and error analysis also described.The result in this thesis show that the project of data processing in this subjectis feasible.Implementations of on-board processing algorithms to perform losslessdata reductions can dramatically reduce the data rates.The research results of thisthesis have great reference value to in-depth study and realization of real-timeprocessing technique of spaceborne Interferometer.