Optical image sequences of spacecraft acquired by space-based monocular cameras are typically imaged through exposure bracketing. The feature deformable alignment network for multi-exposure fusion (SFDA-MEF) aims to synthesize a High Dynamic Range (HDR) from set Low (LDR) images with varying exposures. HDR contains details the observed target in LDR captured within specific luminance range. relative attitude camera coordinate system undergoes continuous changes during orbital rendezvous,...

Feature point detection in inverse synthetic aperture radar (ISAR) images of space targets is the foundation for tasks such as analyzing target motion intent and predicting on-orbit status. Traditional feature methods perform poorly when confronted with low texture uneven brightness characteristics ISAR images. Due to nonlinear mapping capabilities, neural networks can effectively learn features from targets, providing new ideas detection. However, scarcity labeled image data presents a...

Achieving asymmetric transmission effects, especially in an ultra-broadband frequency region, is of particular importance communication systems. Currently available metasurfaces are limited to narrow bands and low efficiencies because the inherently dispersion effects large fluctuations. In this paper, we propose a new strategy realize high efficiency ultra-thin profile by using topologically coding optimization method. The meta-atom consists two outer orthogonal gratings central lattice...

Absorbers have potential applications in the stealth field. However, limited bandwidth and low absorption rate persist existing methods. Moreover, absorbers working frequency range (1-4 GHz) with small size are much more difficult to realize. In this paper, we propose a novel structure, which combines indium tin oxide film metal resonator. The former realizes impedance matching free space broad at moderate while latter shows resonant property frequency. Based on design zigzag-shaped...

In this paper, we propose an approach to design metasurfaces realize superior performance for monostatic and bistatic radar cross section (RCS) reduction within a wide bandwidth. By engineering four subarrays exhibit different hybrid focusing-linear phases metasurface, nearly uniform diffusive scattering can be inherently guaranteed. As illustration, fabricate proof-of-prototype metasurface experimentally demonstrate its wave-diffusion performances. Numerical experimental results both show...

Perfect absorbers are highly desired in many engineering and military applications, including radar cross section (RCS) reduction, cloaking devices, sensor detectors. However, most types of present can only absorb space propagation waves, but absorption for surface waves has not been researched intensively. Surface easily excited on the interfaces between metal dielectrics electronic which decreases their working performances due to electromagnetic disturbances. Thus, it is great...

Attitude estimation for space targets based on inverse synthetic aperture radar (ISAR) is essential various on-orbit operations, including spacecraft status analysis and fall forecast. However, traditional attitude methods ISAR images suffer from poor feature extraction performance. Furthermore, the present can only deal with stabilized spacecraft. In situations where a noncooperative in slow-spinning state, cross-range scaling inaccurate, resulting incorrect estimation. this study, we...

A perfect absorber is highly desired in many engineering applications, including cloaking devices and sensor detectors, but most types of absorbers with chirality-dependence have limited bandwidth. In this paper, we propose a novel broadband chirality-dependent metasurface that consists an array planar spiral elements. The orientation can determine the absorption polarization, such as counterclockwise for right circular polarization (RCP) clockwise left (LCP) absorption. Three steps are...

Instantaneous attitude estimation for spacecraft through optical/ISAR fusion observation is a hot topic in space situational awareness. However, due to the imaging characteristics and domain gap between two data types, it difficult autonomously estimate instantaneous based on fusion. In this paper, an automatic multi-feature framework proposed. We deploy semantic feature extraction networks extract associate kinds of robust features optical ISAR images, algorithm considering cross-range...

Pointing estimation for spacecraft using Inverse Synthetic Aperture Radar (ISAR) images plays a significant role in space situational awareness and surveillance. However, feature extraction cross-range scaling of ISAR create bottlenecks that limit performances current methods. Especially, the emergence staring imaging satellites, characterized by complex kinematic behaviors, presents novel challenge to this task. To address these issues, article proposes pointing method based on...

Perfect absorbers are highly desired in many engineering and military applications, including radar cross section (RCS) reduction, cloaking devices, sensor detectors. However, most types of present can only absorb space propagation waves, yet absorption for the surface wave (SW) has not been researched intensively. In reality, when illuminates on metal under large oblique angles, waves be excited interface between dielectric thus would increase RCS influence stealth performance. Here, based...

We make efforts to help the investigator discover hidden conspirators. In criminal cases, investigators or police have full use of messages spoken documents data that they record in files. Thus, mining latent information from is vital them. Information Retrieval area, Latent Semantic Analysis (LSA) an important method for query matching which can underlying semantic relation similarity between words and topics. introduce a network hierarchical structure analyze original message network,...

In the task of space target recognition, due to limited conditions image acquisition, accumulated train dataset and test have obvious differences in different poses, drastic changes representation caused by cross-view greatly restrict performance recognition. this paper, recognition from multi-view stereo is proposed. The method based on estimate depth information, which fused with texture information 2D image, finally uses 3D CNN classify image. network learns inferences without supervision...

Abstract Space-based space surveillance (SBSS) has the advantage of being flexible and highly interpretable, allowing it to play a strategic role in monitoring targets. During actual missions, however, bursts push-frame imaging methods, dynamic noise during observation, large motions other factors can result visible degradation, isn’t easy have corresponding high-resolution (HR) images for low-resolution (LR) acquired at high-speed intersection, which seriously limits existing multi-image...

Abstract 3D reconstruction of space targets using optical measurement data is an important topic in the field surveillance and spacecraft service orbit. The core current mainstream methods to establish feature association between images. In space-based imaging scenes, texture target region missing range view large, which causes great difficulties extraction matching image sequences. Neural radiance technology does not need extract explicit features, its implicit expression scenes has...

The subsystems in a complex system are not independent of each other, but interrelated, and because they different micro-level macro-level, this makes the hierarchical. In process rapid economic development, integration economics management is deepening. Applying statistical analysis method big data to regional can find out rules operation, improve efficiency promote healthy development economy. This article discusses application field puts forward an intelligent decision model economy based...

A position-type engine governor system is designed, in consideration of tracked vehicle mechanical mechanism and a fixed-axis manual gearbox, to realize the speed control meet requirement unmanned vehicle. According modified gearbox transmission requirements, matching strategy was designed for shifting process achieved integrated powertrain control. bench set up, then test carried out. Real world tests verification were out Experiment results shows that can integration

Comparative analysis of quality and safety monitoring technology has always been the most sensitive topic in food field. Quality liquor is prerequisite for maintaining market stability guaranteeing quality. Therefore, it very important to judge correctly. In this study, XGBoost model was used evaluate 4899 samples from Vinho Verde white wine sample dataset northern Portugal. The influence 11 characteristics such as volatile Acidity, alcohol, density, free sulfur dioxide on explained by SHAP,...