Transient intense electromagnetic pulses, characterized by extremely high peak field strength and broad frequency domain distribution, pose severe electromagnetic safety threats to electronic systems. Their accurate measurement is crucial for evaluating radiation source performance and the effectiveness of protection measures. However, ground-reflected waves often cause significant waveform distortion in far-field measurements. Existing narrow-spectrum suppression methods fail due to bandwidth limitations, while environmental adjustment approaches are impractical in complex scenarios, and traditional array beamforming techniques are restricted by signal correlation requirements.

To address the waveform distortion caused by ground-reflected waves in far-field measurements of transient intense electromagnetic pulses, this study proposes a monopole array-based waveform recovery algorithm. It aims to eliminate ground scattering interference and accurately extract direct waves, providing support for related measurements and evaluations.

The principle of direct wave extraction based on monopole array was derived in both frequency and time domains. Potential error sources and corresponding optimization schemes were analyzed. A measurement system was built under ground reflection conditions for experimental tests, and the performance of different algorithms was compared.

Experimental results show that the direct waves extracted by the proposed algorithm match the reference direct waves well, with amplitude error within 0.2 dB and main waveform fidelity coefficient greater than 0.99. The time-domain algorithm is more concise and less affected by interference, while the frequency-domain algorithm enables direct wave recovery with a single system, making it more cost-effective. Compared with traditional technologies, the algorithm expands the applicable frequency band and significantly reduces amplitude calculation error.

The proposed waveform recovery algorithm can effectively suppress ground scattering effects and accurately extract direct waves. It provides reliable support for parameter separation in transient pulse measurements and state evaluation of radiation systems.