聚焦型X射线望远镜相较于准直型望远镜，具有本底低、有效面积大、灵敏度高等优点，在对天体源的时变特征进行精细测量时，卫星指向稳定度、聚焦光学响应及焦平面探测器响应，都会对科学观测产生显著影响。为了评估聚焦型望远镜的科学性能，实现端到端的观测模拟是非常必要且有效的技术手段。本项目拟基于GEANT4软件，以增强型X射线时变与偏振空间天文台（eXTP）有效载荷能谱聚焦望远镜阵列（SFA）为实例，深入研究X射线从天体源至探测器信号读出的整个过程，主要包括：模拟Wolter-I型聚焦镜光学响应，预测其表面误差的影响；研究硅漂移型探测器（SDD）的响应，模拟电子空穴对的输运过程。基于该模拟工具，分析环境因素变化与伪调制信号的关系，指导有效载荷的优化设计，对卫星平台指向精度提出约束，以保证科学目标的实现。最终，本项目拟建立一套通用的观测仿真方法，为后续聚焦型天文卫星项目的方案论证提供技术支持。

Focusing X-ray astronomical telescopes have many advantages compared to collimator-based astronomical telescopes, including low background, large effective area and high sensitivity. When focusing telescopes are used for the detailed timing measurement of astrophysical sources, the pointing stability, optics response and detector response have critical impact on the scientific observations. In order to estimate the performances of the telescope, it is essential to understand the physical interactions during the X-ray detection processes and establish accurate models to represent the physics. An end-to-end simulation is one of the most effective technique for this purpose. In this work, we are going to perform a detailed simulation of the spectroscopy of focusing array (SFA), one of the payloads of the enhanced X-ray Timing and Polarimetry observatory (eXTP), within the framework of GEANT4. It aims to establish the end-to-end simulator, including the interaction between X-rays and matters in the Wolter-I focusing mirror and the response of the silicon drift detectors (SDD). Based on the simulator, it is feasible to study the correlation between the misalignment and the characteristics of spurious quasi-periodic oscillation signals. The study can thus be used to optimize the design of SFA, provide constraints on the alignment budge of the platform and ensure to fulfill the scientific objectives. Finally, this work is to establish a generalized simulation scheme, which can provide technical support for the design of the future focusing X-ray astronomical telescopes.