Effect of phase errors on the accuracy of MUSIC

Expressions are obtained for the measurement variance, for both azimuth and elevation, in terms of the phase error variance and the array geometry, using MUSIC as the DF processing method. MUSIC is a widely known superresolution method, often used as a standard for comparison with other methods. Although the results are derived for MUSIC they are likely to be a good indication of the performance obtainable by other methods using the same array. The results are derived only for the case of a single signal present; for multiple, well separated signals (with the number of signals considerably less than the number of array elements) the accuracies should be close to these results. The derived expressions are plotted for a number of arrays, showing the expected variation in accuracy with azimuth or elevation. Simulation results are shown which agree well with the theoretical curves.