Vaisala RVP900

USER’S MANUAL__________________________________________________________________
34 __________________________________________________________________ M211322EN-D
2.6.3 RVP902 Signal Processing
Computer
The dual quad-core Intel Xeon-based computer acts as the host to the
Linux operating system and provides all of the computing resources for
processing the I/Q values that are generated by the RVP901 IFDR. Dual
hot-swappable hard drives, using a RAID 1 configuration, help to ensure
longevity of the processor, reducing system interrupts. Standard keyboard,
mouse, and monitor connections are available, along with 10/100/1000
BaseT Ethernet port. The system does not require that a keyboard, mouse,
or monitor be connected, which is typically the case at an unattended site.
Computers are available from many vendors, at various speeds. Typically
the computer is equipped with 2 GB RAM. The RVP902 chassis has four
drive bays. A DVD/RW is also provided for software maintenance.
The RVP902 computer also plays host for RVP900 Utilities, which
provide test, configuration, control, and monitoring software as well as
built-in, online documentation.
2.7 Analog Versus Digital Radar Receivers
2.7.1 What is a Digital IF Receiver?
A digital IF receiver accepts the analog IF signal (typically 30 MHz or 60
MHz), processes it, and outputs a stream of WDR digital "I" and "Q"
values. These quantities are then processed to obtain the moment data (for
example, Z, V, W, or polarization variables). Additionally, the digital
receiver can accept the transmit pulse "burst sample" for the purpose of
measuring the frequency, phase, and power of the transmit pulse. The
functions that can be performed by the digital receiver are:
- IF band pass filtering
- "I" and "Q" calculation over WDR
- Phase measurement and correction of transmitted pulse for magnetron
systems (from burst sample)
- Amplitude measurement and correction of transmitted pulse (from
burst sample)
- Frequency measurement for AFC output (from burst sample)
NOTE
The latest versions of the RVP900 software and documentation can be
downloaded for free from Vaisala’s web site.