Accurate detection and localization of unintended emissions from multiple radio-controlled electronic devices have a wide range of security applications. First, this paper introduces a cost-effective mobile array detector. Subsequently, a novel scheme is presented for detection and localization of multiple devices emitting unintended passive emissions. Peak detection is employed in detecting the devices with superheterodyne receivers (SHRs). Experimental results demonstrate that the proposed scheme outperforms the traditional methodologies with a single antenna. A 2-D array is also proposed in this paper for localization of devices with SHRs using the angle of arrival. A new, synthetic aperture radar (SAR)-based scheme called edge synthetic aperture radar (ESAR) is also introduced in this paper for localization. Finally, the results for localization and error in localization are analyzed. The ESAR method reduces the error in localization up to 75% and increases accuracy in detection of multiple devices.