Development of High-Speed Processing of Gravitational Wave Radiometry using GPGPU

全球引力波观测网预计将在2017年或2018年左右启动。引力波辐射测量法是一种利用多探测器和长时间积分从天空的某个方向提取引力波信号的方法，即使引力波是非相干的和微弱的。然而，辐射测量计算需要冗长的计算，如对天空位置的迭代和对长时间观测的短块的迭代。因此，我们的研究计划的目的是利用GPGPU（图形处理单元上的通用计算）高速进行辐射测量计算。与以前的CPU相比，我们实现了大约100倍的GPGPU计算速度。在相同的条件下比较GPU和CPU并不简单，但结果是在相同的性价比下得出的。在此基础上，研究了辐射测量在不同波段的应用变化，如源分离滤波。

The global gravitational wave observation network is expected to start around year 2017 or 2018. Gravitational wave radiometry is a method which will make possible to extract gravitational signal from certain direction of the sky using multi-detectors and long duration integration, even if waves are incoherent and weak. However, the radiometry calculation requires verbose calculations such as iteration for sky positions and of short chunks for long observation. Thus, the aim of our research program is high-speed up of radiometry calculation using GPGPU (General-purpose computing on graphics processing units).We achieved about 100 times faster calculation with GPGPU comparing with previous CPU. It is not straightforward to compare GPU and CPU in equal condition, but the result is derived on same cost-performance. Using this speed-up, we studied the variation of application of radiometry, e.g. source separate filter using different waveband.