The selection of multiple, suitably designed, demodulation reference
signals can enable the measurement of a vehicle's speed using
continuously transmitted frequency modulated (CTFM) signals. The unique
solution of vehicle speed can be used to resolve the range Doppler
ambiguity found in conventional CTFM sonar and radar systems. This can
enable continuous range and speed estimates of high-speed vehicles with
an attendant reduction in transmit power relative to pulse-echo systems
with similar measures of performance due to the 100% duty cycle.