A moving mirror control system of the Fourier transform spectrometer (FTS) based on the feedforward inputs obtained by the intelligent algorithm is proposed in this paper. Feedforward control is an important part of the moving mirror speed control system of the FTS. And it is always difficult to quantitatively calculate the feedforward inputs through a precise mathematical model of the controlled object. Therefore, based on the expected motion law, an intelligent adaptive algorithm for obtaining feedforward inputs of the moving mirror system was designed. The algorithm decomposed the motion stroke into several position points, iteratively obtained the driving quantity of the moving mirror that met the expected instantaneous speed of each position point, and finally obtained the feedforward inputs of the whole motion stroke. The feedforward inputs obtained by the intelligent algorithm combined with the speed loop PID control constitute the complete moving mirror speed control system. Then, we applied the control system to the moving mirror of the FTS and acquired the velocity of the moving mirror. The experimental results show that the control system is feasible, the error of the peak-to-peak velocity is 0.047, and the error of the root mean square (RMS) velocity is 0.003. Compared with the single-speed-loop control system without feedforward inputs, the error of the peak-to-peak velocity is reduced by 43.3%, and the error of the RMS velocity is reduced by 67.7%, realizing a more accurate control of the moving mirror. Therefore, the control system based on the feedforward inputs obtained by the intelligent algorithm is a feasible and effective moving mirror speed control scheme of the FTS.

In order to capture the large-scale interferometric signal generated by the space-borne interferometric infrared Fourier spectrometer (IRIFS) in real time, and overcome the limitations of insufficient sampling rate, transmission rate, and significant signal noise in current equipment, a multi-channel high-speed acquisition system for large-scale interferometric signals is designed. A high-performance analog-to-digital converter (ADC) oversampling scheme is designed, which can realize up to 8 synchronous acquisition channels and has a maximum sampling rate of 125 Msps/Ch to ensure the acquisition of interferometric signals. The scheme of jesd204b inter-board transmission and optical fiber terminal transmission is designed. The inter-board transmission rate is 12.5 Gbps, and the terminal transmission rate is 10 GB/s to ensure high-speed data transmission. A hardware filter is designed to realize spatial noise processing of interference signals and ensure the accuracy of acquisition results. The dynamic performance of the data acquisition (DAQ) card is analyzed using discrete Fourier transform in the frequency domain. The spurious free dynamic range (SFDR) is 84 dB, the signal-to-noise ratio (SNR) is 72.7 dB, and the cross-talk is −81.6 dB, which verifies the dynamic stability of the DAQ card. Finally, the infrared radiation in real space is measured. The average ${\Delta }_{NESR}$ of long wave reaches 48 $\mathrm{mW}\ast {\mathrm{m}}^{-2}\ast {\mathrm{sr}}^{-1}$, and the average ${\Delta }_{NESR}$ of medium wave reaches 12.3 $\mathrm{mW}\ast {\mathrm{m}}^{-2}\ast {\mathrm{sr}}^{-1}$, which verifies the reliability of the system performance. The system is of great significance for large-scale infrared interferometric signal acquisition, and has strong practical application value in multi-channel synchronization, real-time high-speed acquisition, and high-speed data transmission.

The Geostationary Interferometric Infrared Sounder (GIIRS) onboard the FengYun-4B weather satellite provides critical upwelling atmospheric infrared radiance. To address the limitations of the previous sounder (FY-4A/GIIRS) in terms of spatial resolution and spectral coverage, FY-4B/GIIRS has increased the spatial resolution to 12 km and added more spectral channels in the long-wave band to enhance the observation details and information content of weather systems. To evaluate its baseline performance, a comprehensive preflight test campaign—encompassing spectral and radiometric assessments—was conducted in a thermal vacuum (TVAC) chamber. Spectral characterization via laser measurements confirmed the instrument spectral response function (ISRF) is highly consistent with the theoretical cardinal sine function (sinc). Gas-cell tests demonstrated that, after correcting for off-axis effect, the spectral calibration errors are on average less than 5 ppm, validated against Line-By-Line Radiative Transfer Model (LBLRTM) simulations. The radiometric calibration employed temperature-variable blackbodies for noise performance and radiometric accuracy assessments. The radiometric sensitivity, characterized by Noise Equivalent differential Radiance (NEdR), is less than 0.5 and 0.1 mW/(m²·sr·cm⁻¹) in the long-wave infrared (LWIR) and mid-wave infrared (MWIR) bands, respectively. To address the LWIR detector nonlinearity, an iterative polynomial fitting algorithm based on spectral responsivity invariance was implemented. This correction reduces the radiometric deviation from >1.0 K to ~0.2 K, meeting the 0.7 K accuracy requirement across a 180–315 K dynamic range. Conversely, the MWIR band exhibits high linearity but is limited by noise when observing low-temperature scenarios and can only meet the 0.7 K requirement within the range of 250 to 315 K.