High Signal-to-Noise Ratio Method Without Phase Deviation for X-Ray Pulsar Profile Acquisition

High-quality X-ray pulsar observation profiles are vital for both investigating their physical properties and navigation applications. Traditional profile acquisition relies solely on epoch folding, which is limited by observation time and bin size. These limitations often result in low-quality profiles and may even prevent profile extraction under extremely low-photon conditions. This paper proposes a novel method that bypasses time-domain epoch folding, which directly extracts high-quality profile frequency spectra merely by statistical analysis of photon sequences, followed by reconstructs time domain waveforms. The method begin with adopts a new statistical framework based on power spectrum estimation, and the resulting sequence (referred to as the λ sequence) can enable consistent power spectrum estimation. And then to overcome the blind phase issue inherent in power spectrum estimation, it exploits the cyclo-stationary properties of the first-order statistics of pulsar signals, enabling consistent estimation of the amplitude spectrum and accurate recovery of unshifted phase spectrum concurrently through Fourier transform. The high-quality profile is reconstructed by applying inverse Fourier transform after truncating the spectrum to match the actual bandwidth, as the resulting frequency components extend far beyond the pulsar’s signal bandwidth. Validation through Monte-Carlo simulations and real data demonstrates that the proposed method can improve the correlation coefficient by 0.55 and the SNR by 15.05dB, respectively. Moreover, it can achieve comparable profile quality using 1–2 orders of magnitude fewer photons than epoch folding. The lower the photon count, the more significant the improvement, making the method especially suitable for small-area detectors and resource-constrained observation scenarios.