Surrogate model-based optimization of drogue dimensions and towing operations to straighten deep-towed nonuniform arrays

In deep -towed multi -channel seismic systems, nonuniform mass distribution of seismic arrays results in a "W" shape, negatively impacting the exploration resolution. High towing speeds or use of large drogues can straighten the arrays; however, these approaches adversely affect the towing depth and maximum cable tension. Therefore, this study performed system optimization for drogue dimensions, towing speed, and towing cable length by employing an efficient surrogate model -based method. A surrogate model of the drogue that incorporates dimensional variation, along with another surrogate model that merely expresses the relationship between the drag forces and towed -vehicle motions, were used. These surrogate models were connected via nonuniform arrays modeled by an efficient quasi -static iteration method validated using the absolute nodal coordinate formulation. Finally, the drogue dimensions, towing speed, and towing cable length were optimized under constraints of limited towing depth and cable tension; the maximum vertical deviation of array shape was significantly reduced (from 3.0 m to 0.5 m). The quasi -static iteration and surrogate model -based approach affords an efficient means of optimizing the device dimensions and towing operations for marine towed systems.