用于球载望远镜精引导及毫角秒级姿态估计的多传感器融合技术
Multi-sensor fusion for fine-guidance and milliarcsecond-level attitude estimation of balloon-borne telescope
AI总结：
本研究针对球载望远镜的滚动泄漏问题，基于SuperBIT飞行数据开发仿真框架，对比单星与多星引导架构，发现多星估计可显著降低滚动引发的图像运动，为GigaBIT的多星精引导架构研究提供支撑。
AI中文摘要：
球载望远镜依赖精引导系统实现毫角秒级的图像稳定性，以抵消气球环境带来的残余扰动。在这类系统中，快速转向镜（Fast Steering Mirror，FSM）可在两个焦平面轴上稳定图像，但会留下由视轴滚动引发的、与视场相关的系统性残余运动，该效应被称为“滚动泄漏”，对于更宽的视场而言，其影响更为显著。本研究利用2023年超压球载成像望远镜（SuperBIT）科学飞行的数据对滚动泄漏进行了表征，SuperBIT是一台口径0.5米、工作波段从近紫外到近红外的望远镜，在其45晚的科学飞行中已实现毫角秒级的图像稳定性。我们发现，在大量科学曝光数据中，被动焦平面星相机测量值与独立滚动测量值具有强相关性，表明视轴滚动常驱动残余焦平面运动。随后，我们开发了一套结合光学光线追迹、异步导星测量、估计及FSM控制的仿真框架，以研究该行为；利用该框架，我们在真实飞行扰动下对比了单星与多星引导架构的性能。针对SuperBIT的几何构型，我们发现多星估计可将滚动引发的科学视场图像平均运动降低31.8%；对于SuperBIT计划中的更大口径后继型号GigaBIT的代表性几何构型，该降幅可达77.4%。这些结果为GigaBIT进一步研究多星精引导架构提供了依据。
英文摘要：
Balloon-borne telescopes rely on fine-guidance systems to achieve milliarcsecond image stability despite residual disturbances from the balloon environment. In these systems, the Fast Steering Mirror (FSM) stabilizes the image in two focal-plane axes, but leaves systematic, field-dependent residual motion induced by boresight roll. This effect, referred to as roll leakage, becomes more important for wider fields of view. In this work, roll leakage is characterized using data from the 2023 Superpressure Balloon-borne Imaging Telescope (SuperBIT) science flight. SuperBIT is a 0.5-m near-ultraviolet to near-infrared telescope that demonstrated milliarcsecond-level image stability during its 45-night science flight. We find that passive focal-plane star-camera measurements correlate strongly with independent roll measurements across a large set of science exposures, showing that boresight roll frequently drives residual focal-plane motion. We then develop a simulation framework combining optical ray tracing, asynchronous guide-star measurements, estimation, and FSM control to study this behavior. The framework is used to compare single-star and multi-star guidance architectures under realistic flight disturbances. For the SuperBIT geometry, we find that multi-star estimation reduces average roll-induced science-field image motion by 31.8%, increasing to 77.4% for a representative geometry of GigaBIT, SuperBIT's planned larger-aperture successor. These results motivate further investigation of multi-star fine-guidance architectures for GigaBIT.
