Abstract
This report proposes a new signal processing method in the Lofar-Gram used target signal detection in the passive sonar. Conventionally, we used FFT-method for frequency analysis in the Lofar-Gram. But it has some problems when a super-narrow band FFT analysis is utilized. So, we use an instantaneous covariance method that is an improved version of covariance method being one of the linear predictive method, and certified this method has better performance than conventional FFT-method.
