Double-null pattern synthesis for low-angle tracking

In omnidirectional array, when tracking low elevation targets, conventional difference pattern is suffered from the multipath echoes and the resulted target elevation angle will oscillate evenly point at the image target direction. Double-null difference pattern is a effective monopulse technique for low-angle tracking against low elevation multipath. Analyse why simple beam linear superposition from the published reference is not effective again to form double-null difference pattern in omnidirectional array, and put forward our synthesis method based on the reasonable constraint conditions and LS criteria to the constrained shaping weight-vector. Computer simulations using a 100-element LUA shown this double-null pattern synthesis technique is effective. Based on the under-determined constraint conditions, using LS to approximation to the original weight-vector can be seen as a new synthesis method for the constrained pattern.