  An accurate delay and Doppler estimation method for a radar system using time
and frequency-shifted pulses with pseudo-random numbers is proposed. The
ambiguity function of the transmitted signal has a strong peak at the origin
and is close to zero if delay and Doppler are more than the inverses of the
bandwidth and time-width. A two-dimensional (2D) sinc function gives a good
approximation of the ambiguity function around the origin, by which fractional
delay and Doppler are accurately estimated.
