User's Manual

RVP8 User’s Manual
October 2005
TTY Nonvolatile Setups
3–21
Transmitter phase switch point: –1.00 usec
This is the transition time of the RVP8’s phase control output lines during random
phase processing modes. The switch point should be selected so that there is
adequate settling time prior to the burst/COHO phase measurement on each pulse.
This question only appears if the PHOUT[0:7] lines are actually configured for phase
control (See Section 3.2.1).
Limits: –500 to 500 msec.
Polarization switch point for POLAR1: –1.00 usec
Polarization switch point for POLAR2: 1.00 usec
The RVP8’s POLAR1 and POLAR2 digital output lines control the polarization
switch in a dual-polarization radar. During data processing modes in which the
polarization alternates from pulse to pulse, the transition points of these control
signals are set by these two questions. The values are in microseconds relative to
range zero; the same units used to define the start times of the six user triggers. The
logical sense of POLAR1 and POLAR2 is set by questions described in Section 3.2.4.
Limits: –500 to 500 msec.
3.2.5.1 Special Options for Tx Synthesis
Several of the dialogs described in the previous section will be modified when the RVP8 is
equipped with an RVP8/Tx Digital Transmitter Card that has been configured for Tx waveform
synthesis in the Mz menu. In this case, each of the RVP8’s four “pulsewidths” can select an
entirely different type of transmit waveform and associated matched receiver.
For example, PW-0 and PW-1 could transmit conventional 0.5msec and 2.0msec CW pulses that
are received using the bandpass filters described in Section 3.2.5. But within this same system,
PW-2 and PW-3 could be further configured as, perhaps, 20msec and 40msec compressed
non-linear FM waveforms. This makes it very easy for application software such as ascope to
transparently switch between radically different Tx waveforms simply by requesting a different
“pulsewidth” for each one.
The following questions will appear in the Mt<n> menu (immediately after the Range Mask
Spacing question) when digital Tx waveforms are being synthesized.
Tx Waveform – 0:CWPulse, 1:LinFM, 2:NLFM : 2
The RVP8 supports three standard Tx waveforms: a conventional fixed-frequency
CW pulse, a linear FM chirp, and non-linear FM. The CWPulse can be used as a
pulsed Doppler waveform in all the same ways that a Klystron or Magnetron system
having a traditional pulse forming network would be used. The linear and non-linear
FM waveforms, however, are compressed pulses that are intended to be transmitted
by a wide-bandwidth Klystron/TWT/SolidState amplifier.
Note: The RVP8 internal APIs permit code developers to create arbitrary waveforms
for transmission. The three types mentioned above are the out-of-the-box selections
that are standard on all RVP8 processors.