In this paper, we discuss high-resolution target sensing through the exploitation of multi-frequency sparse array processing. By using simple design examples of a three-element sensor array coupled with the sensing signals consisting of three well-designed frequencies, we provide insights to achieve a high number of consecutive lags, unique lags, and array aperture. Such multi-frequency sensor arrays with reduced number of sensors can be attractive in many applications to achieve effective sensing with a low cost.

Sparse array; multi-frequency sensing; group sparsity; DOA estimation