Performance analysis and correlation selection with Doppler measurements

In target tracking system, Doppler radar or active sonar can provide both range and range rate measurements. With some kinds of waveforms, the range and range rate measurement errors are correlated. It is pointed in [1] that the negative correlation can improve the steady state tracking performance greatly and the tracking performance under positive correlation will be worse than that under no correlation. With further simulation in this paper, it can be seen that the tracking performance under positive correlation is not always worse than that under no correlation. Under the assumption that the range and range rate accuracy are not affected by the correlation, the relationship between the tracking performance and the correlation is revealed through one-step analytical analysis. For better tracking performance, the absolute value of the measurement correlation coefficient should be as big as possible and its sign should use the opposite sign of the one step prediction covariance correlation.