A vertically integrated electronically steered phased array that employs beamsteering using a programmable phase locked loop including a local oscillator. The system comprises a Global-Positioning-System receiver that uses a classified red cryptographic key to decode the P signal from one or more of the Global-Positioning-System constellation of satellites. The measurement position is changed by, for example, scanning the excitation light, moving the sample, moving a lens that collects the excitation light in the sample so as to change the light-collecting position in the sample, etc. A lens unit is often disposed on an imager included in the imaging unit.