Operator Sampling is a generalization of classical sampling in which the objects being reconstructed from limited data are operators rather than functions.This theory is rooted in work of Kailath and Bello in the 1960s on the sounding of spread-spectrum communication channels.We will describe the tools from time-frequency analysis that are brought to bear on the problem,and describe connections to finite frame theory,capacity estimation of time-variant channels,and compressive sensing.