【摘要】 野外干扰波调查是指导正确选择野外采集参数的重要手段 ,直接影响采集数据的质量。本文采用方形排列干扰波调查方法 [1]对西藏工区的实际数据进行了分析和研究 ,得知在高速层出露地区干扰波速度范围是 30 0 0～ 4 70 0 m/ s。其中速度小于 350 0 m/ s的干扰波可通过野外组合有效压制 ;而速度大于 4 0 0 0 m / s的干扰波则很难压制 ,且其方向决定于周围高速层出露的形态。此外 ,由于地层倾角陡 ,反射波也存在一定的方向特性。因此在这类地区作数据采集时 ,采集参数要随地表高速层出露的形态和反射层的陡度而改变。此次研究结果表明 :方形排列干扰波调查方法与其它观测方法相比 ,能更准确地求取干扰波速度、方向 ,而且还具有求取信噪比的独特功能。更多还原

【Abstract】 Noise wave investigation in the field is an important means for determining optimum field parameters, and it causes direct influence on the quality of data acquisition. Noise wave investigation using box wave test was conducted to analyse real data in Tibet prospect, and it led to the following conclusions: ·The velocities of noise waves range from 3000m/s to 4700m/s in cropped high velocity layer. ·Noise wave whose velocity is lower than 3500m/s can be suppressed by field array;but the noise wave that has velocity above 4000m/s can hardly be suppress ed, and its direction depends on the shape of the cropped high velocity medium. ·High steepness of formations causes the directionality of reflection wave; therefore, acquisition parameters must depend on both the surface shape of cropped high velocity layer and the steepness of reflection horizons. ·Noise wave investigation using box wave test obtains more accurate velocity and directionality of noise wave than other methods, besides it has specific function of S/N ratio estimation.更多还原