数字滤波器是影响海洋重力数据处理成果质量的关键技术之一。该文提出了一种实时正反有限冲击响应(FIR)滤波算法，推导了具有线性相位正反FIR滤波器表达式并设计了实时滤波方案：该算法设计出的滤波器在所有的采样频谱内都满足严格意义上的线性相频特性；基于该算法设计的低通滤波器的阻带衰减大，有利于抑制海洋重力数据中的高频噪声。船载重力试验结果表明，在海洋重力数据处理中上述正反FIR滤波器的滤波器实时性好，滤波效果与事后正反FIR滤波器相当，优于单正向FIR滤波效果。

Digital filter is one of the key technologies that affect the quality of marine gravity data processing results. A real time positive and negative finite impulse response(FIR) filtering algorithm is proposed and the expression of the positive and negative FIR filter with linear phase is derived. The filter designed by this algorithm satisfies the strict linear phase-frequency characteristics in all sampling spectrums, and will not cause nonlinear distortion to the signal; The low-pass filter designed by the algorithm has a large stop-band attenuation, which is beneficial to suppress high-frequency noise in ocean gravity data. The ship-borne test shows that the filtering effect of the positive and negative FIR filter is better than that of the traditional FIR filter in ocean gravity data processing, and comparable to offline processing results.