标题： 面向遥感海洋学的星载雷达高性能仿真：应用于高度计场景 显示英文标题

标题： High Performance Simulation of Spaceborne Radar for Remote-Sensing Oceanography: Application to an Altimetry Scenario

摘要： 在本文中，我们详细介绍了我们用于卫星海洋学的星载雷达模拟器的高性能实现。 我们的软件模拟海面和信号，尽可能地模仿测量过程，从其最低层次机制开始。 从这个角度来看，原始数据被计算为许多被照亮的散射体的总和，其随时间变化的特性与表面粗糙度、地形和运动学有关。 为了实现高效的性能，我们大量使用GPU计算。 此外，我们提出了一种快速模拟模式，该模式基于一个假设，即在一个距离门内的瞬时多普勒谱的变化时间尺度明显大于脉冲重复间隔（PRI）。 然后，海面可以以远低于脉冲重复频率（PRF）的频率更新，大大降低计算成本。 当表面更新时，会对所有距离门计算多普勒谱。 然后通过一维逆傅里叶变换获得信号段，并进行加权以确保表面更新之间的平滑时间演变。 我们通过Sentinel-3 SRAL仪器的雷达高度计模拟案例验证了这种快速模拟模式，结果表明，使用最先进的算法可以对模拟的原始数据进行聚焦和提取。 最后，我们展示了使用适度的硬件配置，我们的模拟器可以在一天内生成足够的数据来计算场景的SWH和SSH谱。 这表明我们实现了重要的最先进的速度提升。 显示英文摘要

摘要： In this paper, we detail the high-performance implementation of our spaceborne radar simulator for satellite oceanography. Our software simulates the sea surface and the signal to imitate, as far as possible, the measurement process, starting from its lowest level mechanisms. In this perspective, raw data are computed as the sum of many illuminated scatterers, whose time-evolving properties are related to the surface roughness, topography, and kinematics. To achieve efficient performance, we intensively use GPU computing. Moreover, we propose a fast simulation mode based on the assumption that the instantaneous Doppler spectrum within a range gate varies on a timescale significantly larger than the PRI. The sea surface can then be updated at a frequency much smaller than the PRF, drastically reducing the computational cost. When the surface is updated, Doppler spectra are computed for all range gates. Signals segments are then obtained through 1D inverse Fourier transforms and pondered to ensure a smooth time evolution between surface updates. We validate this fast simulation mode with a radar altimeter simulation case of the Sentinel-3 SRAL instrument, showing that simulated raw data can be focused and retrieved using state-of-the-art algorithms. Finally, we show that, using a modest hardware configuration, our simulator can generate enough data in one day to compute the SWH and SSH spectra of a scene. This demonstrate that we achieved an important state-of-the-art speed-up.