发表机构
Brookhaven National Laboratory（布鲁克海文国家实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文介绍基于RFSoC的BMX双输入光谱仪/相关器，实现直接射频采样与100 GbE传输，通过天空观测验证性能，并论证了向八输入系统扩展的可行性。
AI 中文摘要
我们描述了在布鲁克海文国家实验室的重子映射实验（BMX）干涉阵列上部署的、基于Xilinx ZCU208射频片上系统（RFSoC）构建的双输入光谱仪/相关器的实现与天空调试。该系统结合了直接射频采样、基于FPGA的相关处理和100千兆以太网（GbE）可见度传输。两个输入在1050 MHz下直接数字化，无需模拟下变频，并被划分为2048个频率通道。相关器形成两个自相关以及互相关的实部和虚部，在片上存储器中累加，并以固件控制的固定速率将频谱作为UDP数据包传输。两次独立的观测活动分别使用500毫秒和100毫秒的累加时间，产生了958,918次连续累加，没有丢失、重复或损坏的数据包。在所有1.96e9个通道样本上满足柯西-施瓦茨不等式，确认了正确的场识别和定标。天空验证包括六个GNSS频段中的致密源凌日，具有预期的条纹；在预测时间对天鹅座A天顶凌日的相干探测；以及在两个天线上通过自相关独立探测到的银河系中性氢（HI）平面穿越。该相关器的输入数量可参数化，算术运算量随输入数量二次增长。为了扩展到BMX的完整八输入双极化系统，一个针对已部署固件验证的占用率模型表明，当移动到UltraRAM时，可见度缓冲可以容纳，而多瓦片同步、逻辑利用率和时序收敛仍需在八输入实现中得到验证。
英文摘要
We describe the implementation and on-sky commissioning of a two-input spectrometer/correlator built on a Xilinx ZCU208 Radio Frequency System-on-Chip (RFSoC) and deployed on the Baryon Mapping eXperiment (BMX) interferometric array at Brookhaven National Laboratory. The system combines direct RF sampling, FPGA-based correlation, and 100 Gigabit Ethernet (GbE) visibility transport. Two inputs are digitized directly at 1050 MHz without analog downconversion and channelized into 2048 frequency channels. The correlator forms two autocorrelations and the real and imaginary parts of the cross-correlation, accumulates them in on-chip memory, and transmits the spectra as UDP packets at a fixed firmware-controlled rate. Two independent campaigns using 500 ms and 100 ms accumulation times produced 958,918 consecutive accumulations with no lost, duplicated, or malformed packets. A Cauchy-Schwarz bound is satisfied across all 1.96e9 channel-samples, confirming correct field identification and scaling. On-sky validation includes compact-source transits in six GNSS bands with the expected fringes, coherent detection of the Cygnus A zenith transit at the predicted time, and a Galactic HI plane crossing detected independently in autocorrelation on both dishes. The correlator is parameterizable in input count, with arithmetic scaling quadratically. For extension to BMX's full eight-input dual-polarization system, an occupancy model validated against the deployed firmware indicates that visibility buffering fits when moved to UltraRAM, while multi-tile synchronization, logic utilization, and timing closure remain to be demonstrated in an eight-input implementation.
Comments51 pages, 8 figures, submitted to SPIE JATIS
