A method and apparatus for precursor based radar

A method and apparatus is described for signal processing to identify an object in an environment. A precursor associated with an electromagnetic wave interacting with the object is received and a property of the object identified using precursor characteristics. The electromagnetic wave is transmitted with a characteristic including a pulse having a sharp rise time so as to generate the precursor. The pulse is generated using a circuit including capacitive discharge and a semiconductor device such as a Drift Step Recovery Diode. Alternatively the pulse may be generated using a microwave diode switch and a broadband semiconductor amplifier or a traveling wave tube amplifier. The characteristic may also includes a signal with a phase reversal generated by dividing the electromagnetic signal and phase modulating the first electromagnetic signal with the divided signal to generate the phase reversal so as to generate the precursor. A receiver may further establish channels corresponding to the possible precursor spectra and associate each channel with a corresponding possible material property associated with the object including water generated precursor spectra, radar absorptive material generated precursor spectra, and metallic oxides generated precursor spectra. A color display may include an image of the object with possible material properties displayed in a corresponding color in proportion to respective values associated with received precursor spectra.