Development of multi resolution transient electromagnetic virtual wave-field migration imaging method

Deep exploration is an important prerequisite for performing strategic mineral exploration, urban development, and major infrastructure construction. With today's increasing demand for deep exploration, traditional detection methods can no longer meet the needs of deep exploration. Researching new high-resolution and efficient detection methods and technologies has become a problem that urgently needs to be solved. Electromagnetic imaging uses efficient and non-destructive important detection technology in the field of deep exploration. However, traditional electromagnetic exploration methods cannot meet the requirements of depth and resolution in deep exploration. To this end, there is an urgent need to explore new multi resolution electromagnetic imaging methods. The term "multi resolution" refers to the ability to distinguish geological bodies with different scales and burial depths. However, there are three prerequisites to achieving this goal: the multisource transient electromagnetic exploration method and differential pulse excitation, along with the multi pulse scanning detection method, which is to enrich the effective harmonic component of emitted by emitting and ensure the existence of effective response information of the secondary field; multi resolution transient electromagnetic wave-field transformation, which is used to extract a secondary field signal with multi-resolution characteristics after receiving the secondary field signal; and the multi-resolution migration imaging method that uses the virtual wave-field after the wave-field transformation for offset imaging. Through these three methods, highprecision and high-resolution images of complex geological bodies can be obtained.