Spaceborne CO₂ imaging spectrometer is a high spatial resolution, high time resolution, non-contact and long-term monitoring, which is widely applied in the field of monitoring the change of global greenhouse gas. For achieving long-slit, high signal to noise ratio and high spectral image quality, the principle of initial structure of Offner convex grating imaging spectrometer was analyzed by utilizing the central wavelength of tangent of meridian and sagittal rays at slit, enhancing the utilization rate of incident light and avoid vignetting effectively. Based on this scheme, the optical system of Offner convex grating imaging spectrometer was designed. The imaging spectrometer with 35 mm slit, that the swath can achieve 233 km. For enhancing inversing CO₂ gas concentration efficiency and accurately, the spectrometer designed working spectral range at 1590~1620 nm. In addition, in order to achieve 0.1 km spatial resolution at 500 km orbit, the front telescope optical system was designed. The FOV of the front telecentric telescope optical system is 13.14°, focal length is 75 mm. Finally, analyzing the overall optical system that includes telescope and convex grating imaging spectrometer. The design results show that the root mean square (RMS) radius of the sequence diagram is less than 5 μm, and the modulation transfer function of the system at 33 l p/mm is better than 0.7. The design scheme satisfies remote sensing detection requirements of large field of view, high spectral resolution and high signal-to-noise ratio for spaceborne CO₂ imaging spectrometer.

Thermal control of spaceborne micro-hyperspectral imagers (MHIs) operating in inclined low-Earth orbits (LEOs) presents significant challenges due to the complex and dynamically varying external heat flux, which lacks a stable heat dissipation surface. This study proposes a thermal radiation analysis method capable of rapidly deriving accurate numerical solutions for the thermal radiation characteristics of spacecraft in such orbits. A dedicated thermal control system (TCS) was designed, featuring a radiator oriented towards the +z_s plane, which was identified as having stable and low incident heat flux across extreme solar–orbit angle conditions. The system employs efficient thermal pathways, including thermal pads and a flexible graphite thermal ribbon, to transfer heat waste from the imaging module to the radiator, supplemented by electric heaters and multilayer insulation for temperature stability. Steady-state thermal analysis demonstrated excellent temperature uniformity, with gradients below 0.017 °C on critical optics. Subsequent thermo-optical performance analysis revealed that the modulation transfer function (MTF) degradation was maintained below 2% compared to the ideal system. The results confirm the feasibility and effectiveness of the proposed thermal design and analysis methodology in maintaining the stringent thermo-optical performance required for MHIs on inclined-LEO platforms.

High-precision measurements of direct solar radiation spectra are crucial for the development of solar resources, climate change research, and agricultural applications. However, the current measurement systems all rely on a moving two-axis tracking system with a complex structure and many error transmission links. In response to the above problems, a polar-axis rotating solar direct radiation spectroscopic measurement method is proposed, and an overall architecture consisting of a rotating reflector and a spectroradiometric measurement system is constructed, which simplifies the system’s structural form and enables year-round, full-latitude solar direct radiation spectroscopic measurements without requiring moving tracking. The paper focuses on the study of its optical system, optimizes the design of a polar-axis rotating solar direct radiation spectroscopy measurement optical system with a spectral range of 380–780 nm and a spectral resolution better than 2 nm, and carries out spectral reconstruction of the solar direct radiation spectra as well as the assessment of measurement accuracy. The results show that the point error distribution of the AM0 spectral curve ranges from −9.05% to 13.35%, and the area error distribution ranges from −0.04% to 0.09%; the point error distribution of the AM1.5G spectral curve ranges from −9.19% to 13.66%, and the area error distribution ranges from −0.03% to 0.11%. Both exhibit spatial and temporal uniformity exceeding 99.92%, ensuring excellent measurement performance throughout the year. The measurement method proposed in this study enhances the solar direct radiation spectral measurement system. Compared to the existing dual-axis moving tracking measurement method, the system composition is simplified, enabling direct solar radiation spectrum measurement at all latitudes throughout the year without the need for tracking, providing technical support for the development and application of new technologies for solar direct radiation measurement. It is expected to promote future theoretical research and technological breakthroughs in this field.

To address the limitations of unsound physical models and the lack of compensation mechanisms in existing multi-degree-of-freedom programmable lighting methods, we proposed a novel multi-degree-of-freedom programmable lighting approach. The maximum deviation of single-wavelength spectral distribution curves before and after compensation was reduced by 2 times, and energy distribution uniformity was improved by 19.42 times. The wavelength scanning, intensity encoding, and broadband target spectral modulation performances were verified. The spectral modulation errors for CIE standard illuminants A and $D_{65}$ were −1.78% and −0.86%, respectively. This research lays the foundation for high-precision optical detection and analysis, enabling applications in biomedical and material fields.