Wide-field infrared imaging systems are often constrained by detector size, cooling requirements, and payload limitations, leading to the need for multi-FOV detector sharing. However, conventional geometric multiplexing introduces severe spatial aliasing, which significantly degrades target localization performance. This paper proposes a polarization-encoded field-of-view multiplexing method for recovering spatial information from aliased detector measurements. The imaging plane is divided into multiple FOV regions, each assigned a distinct polarization state. After optical folding, the modulated sub-images are superimposed onto a common detector region. Six-channel polarization measurements are used to reconstruct pixel-wise Stokes vectors, and the spatial origin of each pixel is identified through polarization-domain similarity matching and target-level voting. MATLAB-based simulations were conducted using a nine-region multiplexing configuration. The proposed method achieves 97.3% pixel-level classification accuracy under ideal conditions and maintains over 95% accuracy at a noise level of σ = 0.02. The normalized Stokes reconstruction error is below 0.02, and stable performance is observed under polarization modulation deviations within ±10°. By introducing polarization as an additional encoding dimension, the proposed framework enables efficient separation of multiplexed spatial information without increasing detector resources, demonstrating its potential for compact wide-field infrared sensing applications.

Rotating mirror-based space cameras are susceptible to mirror misalignment due to the severe vibrations experienced during rocket launch and the harsh, variable conditions of the space environment, which can result in deviations of the camera’s line of sight. To mitigate this risk, this study proposes a simulation-based on-orbit calibration method for quantifying rotating mirror misalignment using a system of pointing vector equations. The method employs star coordinates as a reference to establish the reference pointing vector for stars, while simultaneously developing a model of the rotating mirror imaging system. By incorporating a misalignment matrix, the actual pointing vector of star points is derived. Subsequently, the reference star pointing vector and the actual star point pointing vector are combined to formulate a system of pointing vector equations. Solving these equations enables precise measurement of the rotating mirror’s rotational misalignment without requiring additional spaceborne equipment. Through simulations, the three-axis misalignment of the rotating mirror is deduced from imaging pixel coordinates, given the known right ascension and declination of reference star points. The influence and patterns of three-axis misalignment on pointing accuracy are analyzed separately. Although validation based on real measurement data remains to be carried out in future work, this simulation-based method provides a theoretical foundation for the calibration of internal orientation elements of space cameras equipped with moving components.

Detector-multiplexed wide-field infrared imaging reuses detector area by folding several sub-fields of view onto a common focal-plane region, but the branch identity of an aliased small target is then unavailable from intensity alone. We propose a dual-domain optical code that combines a fixed Zemax-derived point-spread-function (PSF) library with a conditionally assigned linear-polarization codebook. To replace the earlier feature-level validation, we developed an image-level radiometric simulator that generates four analyzer images under a fixed incident-photon budget, applies mirror transfer, throughput loss, Poisson shot noise, background, read noise, and physical multi-target PSF superposition, and then re-extracts morphology and Stokes observables. The 1037 PSF samples were divided by sub-field into construction, calibration, and locked test sets of 623, 207, and 207 samples. The polarization-to-field assignment was selected by an exhaustive 9! search on the construction data, whereas the compound weight and separability threshold were fixed from calibration data only. In 25,000 locked target-level tests, the equal-weight-form compound decoder achieved 95.936% accuracy (95% confidence interval of 95.684–96.174%), compared with 10.836%, 45.564%, and 88.720% for intensity-only, shape-only, and polarization-only decoding. At the calibrated threshold, the effective capacities were five, four, and nine for the shape, polarization, and compound code spaces. The results are simulation-phase evidence and require experimental verification with measured infrared throughput and component tolerances.

Cylindrical-mirror field-of-view modulation enables detector-multiplexed infrared imaging by encoding object-space information into field-dependent point-spread-function (PSF) morphology. However, the same aberration-engineered optical coding mechanism inevitably expands the target spot and disperses the received energy over many detector pixels, which degrades foreground segmentation and may bury weak targets in photon and readout noise. This paper proposes an energy-concentration recovery algorithm for aberration-encoded infrared small-target detection. Instead of detecting a target from single-pixel peak intensity or Gaussian-mixture-model foreground masks, the proposed method exploits a Zemax-derived and experimentally verified field-dependent PSF library as a physical prior and performs dark-frame subtraction, noise whitening, PSF matched filtering, constant-false-alarm-rate (CFAR) thresholding, and Kalman-based track confirmation. The method acts as a front-end observability recovery module and can be cascaded with the previously developed ten-frame trajectory-morphology recognition algorithm. The apparent novelty lies not in classical matched filtering itself, but in using a measured-field-dependent PSF prior as an observability-recovery layer for an intentionally aberration-coded detector-multiplexing system. End-to-end simulations and 10,800-frame laboratory measurements using measured target trajectories, measured background characteristics, and measured field-dependent spot evidence demonstrate that the proposed detector improves the detectability of dispersed spots, suppresses noise-only track false alarms, and enables sequence-level target discovery under conditions where conventional foreground segmentation is unreliable. The results clarify the practical observability boundary of cylindrical-mirror PSF coding and provide an engineering-oriented detection framework for detector-multiplexed wide-field infrared systems.

For mid-infrared (3–5 μm) asteroid detection scenarios characterized by weak targets and strong background radiation, this study addresses the dynamic range mismatch caused by zodiacal background emission and proposes a high-dynamic-range detection approach based on a digital micromirror device (DMD). The DIRBE-model-based prediction of zodiacal radiation is first used as a prior. Then, an on-orbit observation residual equation is constructed to correct the background parameters. The directional radiance field is mapped into a two-dimensional intensity matrix, from which pixel-level duty-cycle weights are derived and decomposed into binary mask images to drive the DMD, thereby achieving pixel-level exposure-time modulation. This method effectively avoids the issue in conventional dimming schemes where stellar targets are simultaneously modulated. To verify its feasibility and engineering value, both simulation analysis and a proof-of-concept experiment were conducted. The results show that the aperture-photometry signal-to-noise ratios of multiple stars improved from undetectable to detectable levels, with enhanced contrast and overall target visibility. In summary, the proposed method achieves on-orbit suppression of strong zodiacal background radiation and pixel-level dynamic range extension, providing a feasible system solution and practical reference for next-generation asteroid detection payloads.

Polarization-encoded detector multiplexing has recently shown promise for compact wide-field infrared imaging, where multiple field-of-view (FOV) regions are mapped onto a shared detector area and distinguished through Stokes-vector decoding. The practical implementation of this architecture, however, requires reflective folding components for optical path compression and detector reuse. Oblique metallic reflection introduces unequal amplitude attenuation and phase retardation between the p- and s-polarized components, which can deform the designed polarization code before it reaches the polarization-resolved detector. This work establishes a coordinate-consistent Jones–Mueller model for eight peripheral reflections from the internal octagonal mirror and one central direct path. The model distinguishes deterministic polarization-state transport from true depolarization and compares detector-side calibration, encoder pre-compensation, one shared liquid-crystal polarization retarder (LCPR), and a segmented-LCPR upper bound. Using a unified aluminum model at 4.0 um, the mirror displaces the encoded states by several degrees but does not depolarize a fully polarized monochromatic ray. Across 60 Monte Carlo trials with 2000 samples per channel, all principal methods remain approximately 100% accurate at an additive Gaussian-noise standard deviation of σ = 0.02, normalized relative to unit S₀. At σ = 0.15, the ideal-codebook, calibrated-codebook, and pre-compensated decoders achieve 90.87%, 91.24%, and 89.87%, respectively. A shared LCPR provides little global benefit, whereas segmented settings recover individual states at the cost of channel-resolved hardware. The results show that mirror-aware calibration, code-space separation, and physically implementable compensation must be considered jointly.