A Novel Three-Dimensional Imaging Method for Space Targets Utilizing Multistatic ISAR Joint Observation

Three-dimensional (3D) reconstruction of space targets can provide critical information on target structure and dimensions for on-orbit services, fault diagnosis, and other space missions, playing a vital role in maintaining the normal operation of space assets. ISAR equipment, capable of providing high-resolution two-dimensional images of space targets under all-weather conditions, is a primary means for space target observation. However, existing ISAR-based 3D imaging methods for space targets have significant limitations: due to constraints in observation equipment configuration, the attitude estimation of space targets is prone to failure, leading to reconstruction failures. Additionally, the impact of factors such as image offsets on 3D imaging quality has not been adequately considered in the reconstruction process. To address these issues, this paper proposes a 3D imaging method for space targets based on multi-station ISAR joint observation. This method first estimates the target's attitude, then combines octree-space carving techniques for efficient three-dimensional reconstruction, and corrects target region offsets through projection optimization, achieving high-quality three-dimensional imaging. This method employs multi-station ISAR joint observation, ensuring the robustness of attitude estimation. Meanwhile, the application of the octree-space carving technique significantly improves the efficiency of 3D reconstruction. Due to the correction of target area offset, the proposed method can achieve higher-quality 3D imaging results. Simulation results demonstrate that the proposed method exhibits significant advantages in both reconstruction efficiency and 3D imaging quality, highlighting its important application value.