In this report, first, several existing methods for estimating directional spectrum in incident and reflected wave field are discussed from a view point of their own defects. Secondly, a new method(MEMEP),which is developed by modifying the EMEP (Extended Maximum Entropy Principle Method), is proposed as a general and practical method for estimating directional spectrum in incident and reflected wave field. The MEMEP is examined for numerical simulation data, and validity of the MEMEP is discussed.
　The major conclusions are as follows:
1) The MEMEP can be applied for more than three arbitrary mixed gage arrays.
2) The MEMEP has higher resolution power than the MMLM (Modified Maximum Likelihood Method), and can estimate not only incident and reflected wave spectra but also reflection coefficient as a function of wave frequency and wave propagation direction.
3) The MEMEP is suitable to estimate directional spectrum and reflection coefficient with a personal computer because of its easy computation.