Real-time filter decimator for the Spaceborne Fourier Transform Spectrometer

Large amount of data will be produced by sampling FPAs on the SBFTS instrument, which will be a heavy burden for the following data transferring. Decreasing data rate becomes necessary and beneficial to data transfer and archive. This paper presents an approach to reduce infrared interferometric data rate by real-time filter decimator. The input infrared interferometric data is moved down to base-band by DDC, then passed through low-pass FIR filter. Data rate is down sampled by CIC decimator to a manageable level. The implementation of the whole decimation processing has been designed to use Xilinx FPGA (XC1800A) at present time. The result shows signal processing speed is guaranteed and hardware cost is acceptable. Data rate has been decreased from 114.688 Mbps to 28.672 Mbps. Information has been retained in the band of interest. Although this preliminary investigation is still at laboratory level, both the simulation and hardware test give us confidence to go on with our research further.