Pulse coding

From Glossary of Meteorology

pulse coding

The use of modulation within a radar or sodar pulse to increase the range resolution beyond that normally achievable with a pulse of the same length.

In a common technique, the phase of the transmitter carrier is inverted several times in an optimized sequence during the transmitted pulse. This modulation is undone by a complementary process in the receiver to produce an effective pulse length narrower by a factor equal to the number of inversions in the transmitted pulse sequence.
See pulse compression.