Revista: IEEE Aerospace and Electronics Systems Magazine. Vol. 15. Nº 4. Pp. 23-28. Abril 2000.

Autores: J. Sanmartin, M Burgos y F. Pérez

One of the best known weakness of radar sensors in defense and security applications is the necessity to radiate a signal, wich can be detected by the target, so being possible (easy in fact) that the target is alerted abour the presence of a radar before the radar is alerted abour the presence of a target. In this contex, Low Probability of Interception (LPI) Radars try to use signals that are difficult to intercept and/or identify. Spread spectrum signals are strong candidates for this application, and systems using special frequency or polyphase modulation schemes are being exploited. Frequency hopping, however, has not received much attention.