A considerable fraction of incident high energy photons from astrophysical transients such as Gamma Ray Bursts (GRBs) is Compton scattered by the Earth’s atmosphere. These photons, sometimes referred to as the “reflection component”, contribute to the signal detected by space-borne X-ray/γ-ray instruments. The effectiveness and reliability of source parameters such as position, flux, spectra and polarization, inferred by these instruments are therefore highly dependent on the accurate estimation of this scattered component. Current missions use dedicated response matrices to account for these effects. However, these databases are not readily adaptable for other missions, including many upcoming transient search and gravitational wave high-energy electromagnetic counter part detectors. Furthermore, possible systematic effects in these complex simulations have not been thoroughly examined and verified in literature. We are in the process of investigation of the effect with a detailed Monte Carlo simulations in GEANT4 for a Low Earth Orbit (LEO) X-ray detector. Here, we discuss the outcome of our simulation in form of Atmospheric Response Matrix (ARM) and its implications of any systematic errors in the determination of source spectral characteristics. We intend to apply our results in data processing and analysis for AstroSat-CZTI observation of such sources in near future. Our simulation output and source codes will be made publicly available for use by the large number of upcoming high energy transient missions, as well as for scrutiny and systematic comparisons with other missions.

来自天体物理瞬变（如伽马射线暴 (GRB)）的入射高能光子中有相当一部分是由地球大气层散射的康普顿。这些光子有时被称为“反射分量”，有助于星载 X 射线/γ 射线仪器检测到的信号。因此，这些仪器推断的源参数（例如位置、通量、光谱和偏振）的有效性和可靠性高度依赖于对这种散射分量的准确估计。当前任务使用专用响应矩阵来说明这些影响。然而，这些数据库并不容易适用于其他任务，包括许多即将到来的瞬态搜索和引力波高能电磁反探测器。此外，这些复杂模拟中可能的系统影响尚未在文献中进行彻底检查和验证。我们正在通过详细的蒙特卡洛模拟来调查效果GEANT4用于低地球轨道 (LEO) X 射线探测器。在这里，我们以大气响应矩阵 (ARM) 的形式讨论我们的模拟结果及其在确定源光谱特性时任何系统误差的影响。我们打算在不久的将来将我们的结果应用于 AstroSat-CZTI 对此类源的观测的数据处理和分析。我们的模拟输出和源代码将公开用于大量即将到来的高能瞬态任务，以及与其他任务的审查和系统比较。