SimStr: A C++ program for offshore seismic towed-streamer positioning data simulation

Abstract

Offshore seismic exploration requires accurate positions of towed streamers and seismic receivers. Because the actual positions of underwater streamers cannot be accurately determined, few effective evaluation methods for streamer positioning algorithms/software have been developed, besides simulations. However, most simulated data used in streamer positioning research are static; they lack physical meaning and neglect to consider the complex motion characteristics of the streamers caused by the towing vessel and current. To address this limitation, we have developed a C++ program for simulating streamer positioning observations, called SimStr. Based on the motion equation of underwater streamers, we use the finite-difference method to obtain a dynamic streamer shape, for which a box method is used to discretize the streamer motion in space and time. The positioning data are then simulated based on the dynamic streamer shape. We elaborate the structure of the program, for which the code of core algorithms was implemented to have good extendibility, efficiency, and portability, while ensuring high performance. As an example, we determine the simulated streamers of a vessel turning around to demonstrate the effectiveness of the code. Furthermore, we input the simulated data into a self-developed streamer positioning program and a commercial software to evaluate their positioning results and ultimately validate the simulated data.