Since terahertz (THz) wave spectroscopy has been utilized to detect a number of chemical and explosive materials and related compounds by providing their spectral signatures in the THz frequency range, there is an interest in THz wve spectroscopy as a technique to sense improvised explosive devices. However, due to the severe water vapor attenuation of THz waves in the atmosphere, the reliable sensing range of THz wave spectroscopy has been limited to relatively short distances. This invention provides a method of analyzing a remotely-located object including the step of illuminating at least a portion of a targeted object with electromagnetic radiation to induce a phase transformation in the targeted object, wherein the phase transformation produces an emitter plasma, which emits THz radiation. The method also includes the step of ionizing a volume of an ambient gas to produce a sensor plasma by focusing an optical probe beam in the volume and the step of detecting an optical component of resultant radiation produced from an interaction of the focused optical probe beam and the THz radiation in the sensor plasma. Detecting an optical component of the resultant radiation emitted by the sensor plasma facilitates detection of a characteristic fingerprint of the targeted object imposed onto the THz radiation produced as a result of the induced phase transformation.