Detector-level simulation closure of radio air-shower reconstruction with fixed equal-prior geomagnetic templates

Abstract

Autonomous radio arrays reconstruct air showers from trigger-selected ADC traces rather than from ideal electric-field footprints. We present a detector-level simulation-closure test that connects RF-chain-triggered ZHAireS event packages to direction, energy and quality labels. Geometry is reconstructed from voltage amplitudes and station timing. The ADC traces are then inverted through the RF chain, restricted to 50--200 MHz and reduced to the geomagnetic peak amplitude $|E_{x_π}|$ in a radio-core-recentered shower plane. Energy is obtained by fitting a fixed equal-prior mean of locked iron and proton template families. The estimator uses neither the simulated primary label nor an empirical amplitude or zenith scale. Of 972 event packages, 711 pass a common reconstructed-quality gate in the raw-noisy weighted, raw-hard-denoised equal-weight and clean-reference branches. Their mean fractional energy residuals are $+1.20\%$, $+0.55\%$ and $-0.10\%$, with event-to-event scatters of $14.51\%$, $14.40\%$ and $14.25\%$, respectively. The median truth-level opening-angle residual is $0.050^\circ$ in this selected simulated sample. These aggregate values conceal a zenith-dependent energy residual, from about $-8\%$ at $60^\circ$--$70^\circ$ to $+11\%$ at $80^\circ$--$85^\circ$, with substantially larger biases in sparsely populated edge bins. The results establish an internally consistent reconstruction baseline for selected simulated event packages, not a deployed-array resolution or exposure.