f Simultaneous Sourcing Without Compromise

The use of high-efficiency simultaneous sourcing methods results in a signal-to-noise<br>compromise. Noise arises because multiple seismograms need to be recovered or separated<br>from a smaller number of vibroseis field records compared to methods, such as HFVS (High<br>Fidelity Vibratory Seismic), in which there are as many sweeps as there are vibrators. We<br>show that iterative methods can improve the separation and remove noise for seismograms<br>recorded with multiple vibrators operating simultaneously with a single sweep. The iterative<br>methods start with an initial separation. Then, updated seismograms are produced by<br>adjusting them to match the survey data and to satisfy characteristics of noise-free<br>seismograms. The match to survey data involves reconvolving parts of the initial<br>seismograms with an estimate of the vibrator signatures and stacking. The method is<br>especially effective at removing the noise at the bottom of records for Continuous-HFVS SM<br>(Krohn and Johnson, 2005). With these iterative methods, the full efficiency of simultaneous<br>sourcing can be obtained without a noise compromise.