1-byte Velocity Format (DB_VEL)

This is the mean velocity with respect to the Nyquist velocity.

In data product files, the value 255 is used to indicate area not scanned. The Nyquist velocity is wavelength times PRF divided by 4. For 2:3 dual PRF mode, it is doubled; for 4:3 PRF mode, it is tripled, and for 4:5 PRF mode it is quadrupled over that of the higher PRF. For alternating polarization it is halved.

$v e l o c i t y = N − 128 127 × N y q u i s t$

0	Velocity data not available at this range
1	Unambiguous velocity towards the radar
128	Zero velocity
255	Unambiguous velocity away from the radar