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...

The 2-D inverse synthetic aperture radar (ISAR) images of space targets vary with the viewing angles and are not suitable for automatic target recognition (ATR), thus requiring 3-D reconstruction techniques. Conventional techniques either use monostatic incoherent processing retrieval or exploit multistatic but coherent reconstruction. In this article, we combined aspects to investigate reflectivity radar. Space objects periodically revisit same ground area. Multipass interferometric...

A large amount of waste slurry is produced during the construction pipe jacking projects. To avoid occupying too much urban land, it needs to be rapidly reduced. Due complex composition slurry, existing dewatering methods face problem low efficiency, and soil after difficult recycle as materials due high water content strength. There currently a lack research on resource utilization from In response this problem, paper studies flocculation-settling characteristics mechanical properties...

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...

Height extraction by radar remote sensing is an attractive issue for the building detection and recognition. According to analysis on geometrical properties in SAR imagery, a novel height estimation algorithm proposed following model-based structure prediction matching strategy. The range Doppler equation introduced simplified 2D slant image plane. An evaluation function implementing ratio of exponentially weighted averages (ROEWA) also established between predicted observed image. By...

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...

The performance of classic radar geometry based on the line-of-sight (LOS) signal transmitted from to target in free space is affected by multipath echoes urban areas, where non-line-of-sight (NLOS) signals reflected obstacles are received radar. Based prior information situation, this article proposes a novel two-stage localization algorithm with exploitation dense clutter environment. In offline stage, propagation parameters uniformly distributed samples field view predicted ray-tracing...

Cross-range scaling of sequential inverse synthetic aperture radar (ISAR) images is a vital problem for the three-dimensional (3D) reconstruction spatial targets. Specifically, since angular velocity targets cannot be accurately estimated due to their non-cooperative nature, obtained cross-range coordinates scattering points often have non-negligible errors. The errors may result in serious distortion reconstructed geometry targets, which makes consequent target recognition and...

The conventional two dimensional (2D) inverse synthetic aperture radar (ISAR) imaging fails to provide the targets' three (3D) information. In this paper, a 3D ISAR method for space target is proposed based on mutli-orbit observation data and an improved orthogonal matching pursuit (OMP) algorithm. Firstly, scattered field converted into set of 2D matrix by stacking slices along elevation direction dimension. Then, OMP algorithm applied recover target's amplitude information via data....

In order to obtain better inverse synthetic aperture radar (ISAR) image, a novel structure-enhanced spatial spectrum is proposed for estimating the incoherence parameters and fusing multiband. The method takes full advantage of original electromagnetic scattering data its conjugated form by combining them with covariance matrices. To analyse superiority modified algorithm, mathematical expression equivalent signal noise ratio (SNR) derived, which can validate our algorithm theoretically....

Space target ISAR image components segmentation is an important foundation of space recognition based on image. Considering the difference between and optical main body has diverse distribution pixels from subcomponent in image, this paper proposes a idea that segments after CLEAN: firstly, we develop adaptive region growing method to segment emphatically analyses solves setting problem threshold method; then, order divide residual subcomponent, exploit proximity propose iterative...

With the improvements of spaceborne and airborne SAR system resolution, applications radar remote sensing has been extended to building 3D geometric information retrieval reconstruction from urban images, which is foundation build-up areas analysis. This paper mainly focuses on problem height estimation a single high resolution (HR) image scenes. A model based method combined with segmentation framework proposed. optimizes new likelihood measure between projection buildings observed over...

In order to solve the problem of in-shore ship extraction from remote sensing image, a novel method for high resolution (HR) optical image is proposed via salience structure feature and GIS information. Firstly, berth ROI located in with aid prior auxiliary Secondly, salient corner features at bow are extracted precisely. Finally, recursive algorithm concerning symmetric geometry target conducted discriminate multi docked targets into mono ships. The results experiments show that this paper...

Abstract Traditionally, radar‐based localisation systems are designed to deal with targets in line‐of‐sight (LOS) scenarios. However, the performance of those radar is limited by multipath echoes reflected from non‐line‐of‐sight (NLOS) and walls urban areas. In recent years, there has been an increasing interest exploitation methods aided environmental knowledge. Based on space diversity provided effect, this article proposes a novel two‐stage method using single monostatic via association...

Real-time detection of time-critical ground targets by wideband radar is a vital task for missiles and unmanned aerial vehicles. It challenging to give consideration efficiency performance with low signal-to-noise ratio, non-uniform clutter distribution, cross section fluctuation, multiple-target overlapping, interfering objects. This paper presents complete method including integration, tracking. First, an improved non-coherent integration algorithm based on velocity prediction via Keystone...

A space-based bistatic radar system composed of two radars as the transmitter and receiver respectively has a wider surveillance region better early warning capability for high-speed targets, it can detect focused space targets more flexibly than monostatic or ground-based system. However, target echo signal is difficult to process due motion both targets. To be specific, will encounter problems Range Cell Migration (RCM) Doppler Frequency (DFM), which degrade long-time coherent integration...

Extracting 3D information from a single image is an interesting but ill-posed problem. Especially for those artificial objects with less texture such as smooth metal devices, the decrease of object detail makes problem more challenging. Aiming at texture-less symmetric structure, this paper proposes novel method pose estimation by introducing implicit structural symmetry and context constraint priori-knowledge. Firstly, parameterized representation, decomposed into series sub-objects regular...

Estimating the 3D pose of space object from a single image is an important but challenging work. Most existing methods estimate known objects and assume that detailed geometry specific known. These are not available for unknown without object. In contrast to previous works, this paper devotes image. Our method estimates only also shape paper, hierarchical model proposed represent prior structure information typical objects. On basis, parameters estimated simultaneously Experimental results...

Radar imaging has been one of the basic functions for modern radar as well searching, detection and tracking, especially those ground-based space surveillance phased array radars. Due to periodic revisiting characteristics in-orbit objects, multi-pass observations targets (e.g. satellites) within small pitching angle variation can be accumulated, which lead 3D inverse synthetic aperture (ISAR) image formation. Consequently, strategy allocating limited observation resource a reliable ISAR...