基于动态惩罚加权的浅水OBN直达波与折射波初至联合二次定位方法

海底节点(OBN)法在海洋地震勘探中表现出巨大优势。在实际作业中，由于受海浪、洋流和潮汐等因素影响，OBN实际沉放位置往往偏离预设位置，影响后期数据处理，因此需通过二次定位获取节点在海底的真实位置。在浅海地区，直达波初至数量少、方位分布不均且受炮端干扰，初至难以准确拾取，导致无法利用直达波初至实现精确定位。为此，通过引入信息量更丰富的宽方位折射波初至，实现了一种直达波与折射波联合的OBN定位方法；同时，应用基于动态惩罚加权函数的目标函数，并采用模拟退火法迭代求解，获得更准确的二次定位结果，克服了利用单一直达波定位时因初至信息量不足带来的误差，提高了二次定位精度。利用理论模型数据对方法的有效性和稳定性进行了测试，并应用于M海域实际OBN资料，取得了良好的定位效果，验证了方法的实用性。

OBN secondary positioning method jointly by first breaks of direct and refracted waves in shallow water based on dynamic penalty weighting

Ocean Bottom Nodes (OBN) has shown great advantages in marine seismic exploration. In actual operations，due to the influence of sea waves，ocean currents，tides and other factors，the actual sinking position of OBN often deviates from the preset position，which affects the later data processing. Therefore，it is necessary to obtain the true position of OBN through secondary positioning. In the shoal area，the number of first breaks of direct wave is small，the azimuth distribution is uneven，and it is difficult to accurately pick up the first break due to the interference of gun，so it is impossible to use the first break of direct wave to realize positioning. In this paper，a joint positioning method of direct wave and refraction wave is realized by introducing the first arrival of wide azimuth refraction wave with more abundant information. On this basis，an objective function including first breaks of direct wave and first breaks of refraction wave based on dynamic penalty weighting function is proposed，which is solved iteratively by simulated annealing method to obtain more accurate secondary positioning results. The method overcomes the problem caused by low pickup accuracy when using direct wave only，and improves the secondary positioning accuracy. Through the model data test，the effectiveness of the proposed method is verified，and the stability and reliability of the method are tested when there is error in first break picking. Finally，the method is applied to the actual data of OBN in a sea area，and a good positioning effect is obtained， which verifies the practicability of the proposed method.