arXiv subjects

Fufu Yang

Publications and source records attributed to Fufu Yang.

2 recordsLinked to original sources

arXiv2026

Detector-level simulation closure of radio air-shower reconstruction with native RF-chain inversion and out-of-fold endpoint interpolation

Autonomous radio arrays reconstruct air showers from trigger-selected digitized voltage traces rather than ideal electric-field footprints. We present a detector-level simulation-closure test linking RF-chain-triggered ZHAireS event packages to reconstructed direction, energy and quality diagnostics. Voltage amplitudes and station timing determine geometry through a robust joint timing--amplitude axis fit. Native-grid RF-chain inversion recovers 50--200 MHz electric-field peaks along the shower-plane v cross B axis. Symmetric four-arm iron and proton templates generated with 2 ns time bins provide endpoint estimates that are combined by a nested five-fold out-of-fold interpolation estimator. One estimator is used over the full angular range without a fitted multiplicative energy scale. Of 972 triggered event packages, 725 pass common quality selection in raw-noisy weighted, hard-gated denoised equal-weight and clean equal-weight branches. In the primary reconstructed-zenith range 60--85 degrees, 693 common events have mean energy residuals of -0.05, -0.30 and -0.66 percent with standard deviations of 11.04, 10.90 and 10.75 percent. The hard-gated denoised branch has a median angular separation of 0.052 degrees. Boundary zenith ranges are reported separately; the upper boundary has a mean energy residual of +14.2 percent and a 19.9 percent standard deviation. These results describe cross-fitted closure within a matched simulation framework, not deployed-array resolution or independent energy calibration.

astro-ph.IM↗

arXiv2026

FARSim: a fast RF-chain-aware trigger-screening surrogate for radio detection of ultra-high-energy cosmic rays

Radio arrays provide a scalable route to detecting extensive air showers from ultra-high-energy cosmic rays, but trigger studies for candidate layouts are expensive when every energy, arrival direction, core position and trigger configuration is evaluated with full radio simulations. We present FARSim, a fast surrogate framework that reuses a reduced library of ZHAireS reference footprints to reconstruct ground-plane radio emission and to estimate trigger-relevant observables. The method combines vector geomagnetic and charge-excess field decomposition, geomagnetic-angle and energy scaling, geometrical projection, contour-based core sampling and event-rate integration. We validate the reconstructed field footprints and trigger regions against dedicated ZHAireS simulations, and quantify the computational gain obtained by replacing repeated full shower simulations with fast footprint queries. We further extend the peak-field surrogate to time-domain electric-field synthesis by combining the predicted three-component peak-field vector with geometry-dependent normalized pulse templates. Propagating these traces through an RF-chain response enables voltage-domain threshold and L1-trigger diagnostics. For the validation samples considered here, the time-domain extension reaches a median vector-waveform R^2 of 0.986 over 2112 held-out ZHAireS traces when tested at the true peak amplitude. FARSim is therefore intended as a rapid, physics-informed screening layer for array-layout and trigger studies; absolute exposure predictions and detector commissioning remain the role of full end-to-end simulations.

astro-ph.IM↗