Bistatic radar without transmitted signal-covert altimetry concept

A technique for performing altimetric functions (and possibly very-low-resolution imaging radar) without the transmission of a signal is suggested. The system could benefit an invasive aerospace platform that needs to remain totally electronically silent. The concept uses naturally occurring galactic noise as the illumination signal. A rapid and low-cost processor is also suggested. The results developed are also useful for the particular case of low probability of intercept (LPI) radar in which the transmitter emits a broadband Gaussian-like signal and the receivers cannot locally generate the transmitted reference. Another derivation of the arcsine law is provided along with a measure of its efficiency compared with an optimal receiver