A method of analyzing a remotely-located object includes the steps of inducing a volume of an ionized ambient gas to emit pulsed terahertz radiation directed toward a targeted object by focusing an optical pump beam in the volume and ionizing another volume of the ambient gas to produce a sensor plasma by focusing an optical probe beam in the other volume of ambient gas. The interaction, in the sensor plasma, of the focused optical probe beam and an incident terahertz wave, which is produced by the targeted object reflecting, scattering, or transmitting the pulsed terahertz radiation, produces a resultant radiation. Detecting an optical component of the resultant radiation emitted by the sensor plasma facilitates detection of a signature of the targeted object imposed onto the incident terahertz radiation.