Effects of time alignment errors in coherent distributed radar

Coherent distributed operation between multiple radar systems requires wireless coordination to align the phases and clocks of each node in the distributed array. In this paper, we analyze the effects of time alignment error in distributed radar for three general radar waveforms: continuous-wave pulse, phase-coded, and linear frequency modulated waveforms. The relative matched filter gain as a function of timing error is analyzed through Monte Carlo simulation for arrays of up to 20 nodes. To achieve 90% of the ideal coherent gain with a probability of 0.9, the standard deviation of the timing error between nodes must be ≤ 10% of the pulse width for the continuous-wave pulse, ≤ 3% for a 3-element Barker phase code, ≤ 1.5% for a 7-element Barker phase code, ≤ 0.5% for a 13-element Barker phase code, and ≤ 2% for a linear-frequency modulated pulse with a modulation rate of 5% of the carrier frequency.