# Maximum unambiguous velocity

From AMS Glossary

## maximum unambiguous velocity

The maximum range of radial velocity that can be observed without ambiguity by a Doppler radar, sodar, or lidar.

Velocities outside this interval are folded into the interval. For a pulsed radar or sodar operating with an interpulse period

*T,*or a lidar with an A/D converter sampling interval*T,*the unambiguous velocity interval is -λ/4*T*to +λ/4*T*, where λ is the operating wavelength. This interval can be extended by the use of dual PRF and other techniques.*See*velocity aliasing, Nyquist frequency.