USER’S MANUAL__________________________________________________________________
278 _________________________________________________________________ M211322EN-D
NOP can be used to terminate the free running mode with no other
consequences.
- Time Series mode—The processor acquires, processes, and outputs
one ray of time series samples in response to each PROC command.
Similar to Synchronous mode above. Data are output as 8-bit time
series, 16-bit time series, or 16-bit power spectra.
Optional Dual-PRF velocity unfolding is chosen by command bits eight
and nine. For Doppler data either a 2:3, 3:4, or 4:5 PRF unfolding ratio may
be selected. The RVP900 carries out all of the unfolding steps internally,
so that mean velocity is now output with respect to the larger unambiguous
interval. There is no additional velocity processing needed by the user,
except to change the velocity scale on any displays being generated.
Spectral widths are scaled consistently with respect to the higher PRF, and
require no user modification before being plotted.
When unfolding is selected, the internal trigger generator automatically
switches rates on alternate rays. The switch over occurs immediately after
the last pulse of the current ray has been acquired; thus overlapping the
internal post-processing and output time, with transmitter stabilization and
data acquisition at the new rate.
Output data are selected by the upper six bits of the PROC command.
Packed archive output is selected by setting the ARC bit. Individual byte
or word display output is selected by setting any or all of the Z, T, V, W,
Z
dr
, and K
dp
command word bits. When more than one of these bits is set,
the output array consists of all of the bins for the leftmost selected
parameter, followed by all of the bins for the next selected parameter, etc.
Bits selected in XARG #1 behave the same way, except that the output
order is right-to-left. Both archive and display formats can be selected
simultaneously, in which case the archive format is output first, followed
by whichever individual display format values were also selected. The
archive format is not recommended for use with new drivers, because it
can only handle four of the many possible output parameter types.
When time series mode is selected there are three output data formats
available. For backwards compatibility, there is an 8-bit integer format, in
which the eight most significant bits from the I, Q, and LOG signals are
represented in a byte. This format is not recommended, because it
generally misses weak signals. Vaisala recommends the floating-point
format that uses 16-bits per A/D sample. There is also a 16-bit power
spectrum output that is accurate to 0.01 dB (see also GPARM output word
#10).
In addition to the above output data, the first words of each ray optionally
contain additional information about the ray. These header words are
configured by the CFGHDR opcode, and are included only if the NHD
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