DOA estimation algorithms eliminating ground reflected waves

To solve the problem that the near ground antenna is affected by the ground reflected wave, and thus the accuracy of the direction of arrival(DOA) is greatly reduced, we studied a polarization plane based DOA estimation algorithm to eliminate the effect of ground reflected wave. We used three methods, the ideal ground approximation, reflection coefficient method and array inhibition algorithm to simulate, and compared merits and faults, and the applicability of them. We find out that the ideal ground approximation has a good computation result when the actual ground parameters are similar to the ideal conducting plane parameters. While in other cases, errors are very large. In reflection coefficient method, we obtained the horizontal and vertical reflection coefficients of the ground from electrical conductivity σ, relative dielectric constant ε_r and incident polar angle θ. But this algorithm needs to know the actual ground parameters in advance so that the application scenarios are limited. The array inhibition algorithm skillfully uses the relationships between the direct arrival wave and the ground reflected wave in phase delay and incident polar angle. We can get the new data without the ground reflected wave by shifting phase. Through this new data, the direction of arrival of the incident electromagnetic wave can be calculated accurately. By comparison and analysis, we draw a conclusion that the array inhibition algorithm can be used for any kind of actual ground and we do not need to know the actual ground parameters in advance, and the accuracy of this algorithm is also high. Thus, its application scenarios are not limited and it has large application value.