Performance analysis and comparison of correlative interferometers for direction finding

The correlative interferometer is widely used for finding the direction of arrival with high accuracy, flexibility and broadband operation range. In this paper, the bias and mean squared error of these direction estimates with loss functions such as least squares, correlation coefficients and cosine function, are derived for the correlative interferometer, respectively. The explicit expressions of the mean squared errors for the three correlative interferometers are the same for small measurement noise, and they all achieve the Cramér-Rao bound. The analytical results are also shown to be excellent predictors of empirical results obtained from computer simulation of the correlative interferometer for direction finding with above the loss functions. In addition, the cosine function based correlative interferometer has better performance than the least squares and correlation coefficient based ones for large measurement noise.