Sectioning-Based ADMM Imaging for Fast Node Communication With a Compressive Antenna

In this letter, a novel norm-1 regularized imaging technique, based on the alternating direction method of multipliers (ADMM) algorithm, is presented. This technique divides the sensing matrix of the imaging system in submatrices by columns. This method is capable of imaging metallic targets with a reduced amount of measurements, by sectioning the imaging domain into several regions and optimizing them individually in different nodes. This technique reduces the amount of information to be shared among the nodes, compared to the consensus ADMM that divides the sensing matrix into submatrices by rows. This makes the communication among the nodes faster for large imaging domains that need to be distributed into several computational nodes of a cluster. A compressive reflector antenna (CRA) has been recently proposed as a low cost hardware to provide high sensing capacity. The use of the columnwise division ADMM algorithm in combination with the imaging capabilities of the CRA allows a distributed and quasi-real-time imaging, while reducing the communications among the computational nodes.