The non-scanning radiometer with short-wavelength (SW: 0.2–5.0 μm) and total-wavelength (TW: 0.2–50.0 μm) channels is the primary payload of the Integrated Earth–Moon Radiation Observation System (IEMROS), which is designed to provide comprehensive Earth radiation measurements and lunar calibrations at the L1 Lagrange point of the Earth–Moon system from a global perspective. This manuscript introduces a radiometer preflight calibration methodology, which involves background removal and is validated using accurate and traceable reference sources. Simulated Earth view tests are performed to evaluate repeatability, linearity, and gain coefficients over the operating range. Both channels demonstrate repeatability uncertainties better than 0.34%, indicating consistent and reliable measuring performance. Comparative polynomial regression analysis confirms significant linear response characteristics with two-channel nonlinearity less than 0.20%. Gain coefficients are efficiently determined using a two-point calibration approach. Uncertainty analysis reveals an absolute radiometric calibration accuracy of 0.97% for the SW channel and 0.92% for the TW channel, underscoring the non-scanning radiometer’s capability to provide dependable global Earth radiation budget data crucial to environmental and climate studies.

High-precision hyperspectral remote sensing reflectance measurement of water bodies serves as the fundamental technical basis for accurately retrieving spatiotemporal distribution characteristics of water quality parameters, providing critical data support for dynamic monitoring of aquatic ecosystems and pollution source tracing. To address the critical issue of water surface glint interference significantly affecting measurement accuracy in aquatic remote sensing, this study innovatively developed a novel sensor system based on multi-field-of-view Kohler-polarization technology. The system incorporates three Kohler illumination lenses with exceptional surface uniformity exceeding 98.2%, effectively eliminating measurement errors caused by water surface brightness inhomogeneity. By integrating three core technologies—multi-field polarization measurement, skylight blocking, and high-precision radiometric calibration—into a single spectral measurement unit, the system achieves radiation measurement accuracy better than 3%, overcoming the limitations of traditional single-method glint suppression approaches. A glint removal efficiency (GRE) calculation model was established based on a skylight-blocked approach (SBA) and dual-band power function fitting to systematically evaluate glint suppression performance. Experimental results show that the system achieves GRE values of 93.1%, 84.9%, and 78.1% at ±3°, ±7°, and ±12° field-of-view angles, respectively, demonstrating that the ±3° configuration provides a 9.2% performance improvement over the ±7° configuration. Comparative analysis with dual-band power-law fitting reveals a GRE difference of 2.1% (93.1% vs. 95.2%) at ±3° field-of-view, while maintaining excellent consistency (ΔGRE < 3.2%) and goodness-of-fit (R² > 0.96) across all configurations. Shipborne experiments verified the system’s advantages in glint suppression (9.2%~15% improvement) and data reliability. This research provides crucial technical support for developing an integrated water remote sensing reflectance monitoring system combining in situ measurements, UAV platforms, and satellite observations, significantly enhancing the accuracy and reliability of ocean color remote sensing data.

The Moon serves as an ideal reference radiation source for on-orbit calibration of starborne optical remote sensing instruments. To enhance the characterization capability for lunar spectral radiation, the full-field integrated radiation observation system (FIROS) for lunar hyperspectral irradiance measurement has been developed. FIROS accomplished lunar hyperspectral irradiance measurements in the 400–1000 nm range by integrating and spectrally analyzing the radiation across the entire lunar disc, reducing the angular sensitivity and polarization sensitivity to lunar radiation. Performance tests and preliminary lunar observational experiments conducted on FIROS indicate that the system possesses excellent response linearity and environmental adaptability, with a reduction in lunar tracking accuracy requirements by approximately an order of magnitude compared to push-broom imaging observations. The performance and lunar observation capabilities of the system have been well validated. FIROS provides a lunar observation method that simultaneously achieves full-disk light collection and hyperspectral measurement, demonstrating strong environmental adaptability and laying a solid foundation for enhancing long-term stable lunar observation data and establishing lunar radiation benchmarks.

We propose a Multispectral Earth Polarization Imager (MEPI), which is located at the Earth–Moon system’s Lagrange point L1. The imager can be used to measure the sunlight reflected by the Earth and the Moon. The measured sunlight has specific polarization information and spectral information, which can provide strong support for a comprehensive understanding of the Earth system and the construction of a perfect Earth–Moon system model. The MEPI provides multispectral images with wavelengths of 400–885 nm, and uses four sub-aperture systems to share a main system. The imager can capture the two-dimensional shape and polarization spectral information of the entire Earth at a spatial resolution of 10 km, and all spectral images can be simultaneously acquired on a single detector. The optical system of the instrument was designed and simulated. The simulation and analysis results showed that the camera can obtain high-quality images of the Earth disc with a 2.5° field of view (FOV). The novel MEPI provides a new way to generate climate-related knowledge from the perspective of global Earth observation. The imager can also be used for lunar observation to obtain spectral polarization information on the lunar surface. In addition, it also shows great potential in other applications of space remote sensing spectral imaging.

Solar-induced chlorophyll fluorescence (SIF) provides a direct proxy for vegetation photosynthesis-related information; however, under stress conditions, its relationship with photosynthesis should be interpreted together with absorbed photosynthetically active radiation by chlorophyll (APAR_chl) and non-photochemical quenching (NPQ). This study presents a conceptual design of a compact dual-channel airborne imaging spectrometer for synchronous observation of SIF-related spectral radiance and broadband vegetation-canopy spectral reflectance (BR). A self-collimating shared-optical-path configuration is proposed to reduce the system volume, yielding a simulated optical envelope of 205 × 150 × 120 mm³. Optical simulations predict spectral resolutions better than 0.3 nm over 670–780 nm for the SIF channel and better than 2 nm over 400–780 nm for the BR channel. An asymmetric double Babinet depolarizer is incorporated to reduce polarization-related errors, and the simulated system polarization sensitivity is below 1%. The calculated stray-light ratios of the SIF and BR channels are 0.553% and 0.287%, respectively. LightTools was used to simulate the radiative transfer performance of the instrument under realistic scenes. Furthermore, an end-to-end SIF retrieval simulation was performed to evaluate the retrieval capability of the proposed system. The results indicate that the proposed concept is theoretically feasible and may support future quantitative SIF retrieval and the interpretation of vegetation photosynthetic and stress-related processes.

To enhance the field calibration capability of ground-based lunar observation instruments for long-term continuous monitoring and to optimize the stability and traceability of lunar observation data, this manuscript presents the development of a SI traceable Portable Self-calibrating Absolute Radiation Source (PSARS) based on an electrical substitute radiometer. A self-calibrating radiation transfer model has been established. The system features a “+” structure layout centered around an integrating sphere, which ensures uniformity of the light source while improving system integration. Preliminary performance testing results indicate that PSARS achieves excellent radiative planar uniformity and angular uniformity within the targeted area, both exceeding 99%. During the self-calibration cycle of PSARS, the detector demonstrates high measurement stability for the built-in light source. Ultimately, through comparative validation and uncertainty assessment, the self-calibration accuracy of spectral irradiance for PSARS in the 400–1000 nm wavelength range is better than 2%, meeting the demands for high-frequency, high-stability, and high-precision real-time on-site radiometric calibration under ground-based lunar observation field test conditions. This provides technical support for the construction of high-precision lunar models and the widespread application of lunar calibration technologies.