Pulse position modulation code for the improvement of Doppler shift measurement

Pulse position coding for improving Doppler measurement by pulsed radar with respect to Woodward´s expression of Doppler ambiguity is presented. The code of pulse positions is shown to be analytically obtained from the difference between the required ambiguity expression and that of a constant pulse-repetition frequency signal. One feature of the development is the possibility of codes for reducing the spurious peaks that are encountered in the usual ambiguity expression. This is accomplished by an approximation approach using delta functions.