Benefits of Low Frequencies for Subsalt Imaging

Our analysis shows that frequencies less than 6-7 Hz, if they are recorded in marine surveys, are often very noisy and of little use. Here we analyze the potential benefits of these lower frequencies to justify our extensive acquisition efforts to record them with less noise. <br>We find that the recording and use of low frequencies for subsalt imaging offers the following advantages: <br>1) A sharper wavelet,<br>2) Ability to produce interpretable images where there were none before,<br>3) Ability to improve velocities so that higher frequencies can be imaged. <br>4) Low frequencies penetrate into shadow zones<br>5) Provide stability for wave equation inversion algorithms<br><br>