Migrasi beda hingga adalah salah satu algoritma migrasi yang menggunakan prinsip downward continuation dan gelombang datang yang diselesaikan secara numerik dengan menggunakan beda hingga. Migrasi dalam perangkat lunak ProMAX ini memiliki berbagai algoritma tergantung pada solusi numerik yang digunakan. Dari setiap algoritma migrasi beda hingga ini menunjukkan perbedaan signifikan dalam frekuensi yang dihasilkan. Migrasi dengan algoritma beda hingga eksplisit menunjukkan hasil frekuensi yang lebih baik daripada algoritma beda hingga implisit. Kata Kunci: eksplisit; beda hingga; frekuensi; implisit; migrasi.

Seismic reflection is a proven and effective method commonly used during the exploration of deep mineral deposits in Fujian, China. In seismic data processing, rugged depth migration based on wave-equation migration can play a key role in handling surface fluctuations and complex underground structures. Because wave-equation migration in the shot domain cannot output offset-domain common-image gathers in a straightforward way, the use of traditional tools for updating the velocity model and improving image quality can be quite challenging. To overcome this problem, we employed the attribute migration method. This worked by sorting the migrated stack results for every single-shot gather into the offset gathers. The value of the offset that corresponded to each image point was obtained from the ratio of the original migration results to the offset-modulated shot-data migration results. A Gaussian function was proposed to map every image point to a certain range of offsets. This helped improve the signal-to-noise ratio, which was especially important in handing low quality seismic data obtained during mineral exploration. Residual velocity analysis was applied to these gathers to update the velocity model and improve image quality. The offset-domain common-image gathers were also used directly for real mineral exploration seismic data with rugged depth migration. After several iterations of migration and updating the velocity, the proposed procedure achieved an image quality better than the one obtained with the initial velocity model. The results can help with the interpretation of thrust faults and deep deposit exploration.

Upcoming-wave is the basis of several seismic migration methods that use the principle of 1-way-time by propagating only from the event point to the receiver. The migration method that uses this upcoming wave theory is the finite difference migration and Fourier transformation migration. In this paper, we will elaborate how the theories of these two migrations are related and described from scalar wave equations to various forms of upcoming wave approximations, both differential equation form of space-time (x-t) and frequency - wave number (f-k) form, along with their transformations.