Kustom Signals DRU III, Operator'S Manual

Page: 16 / 27

GENERAL INFORMATION
10
This returning signal is mixed with the transmitted signal
in a balanced I/Q demodulator mixer. The difference in
frequency (Doppler frequency) is proportional to the
speed of the target; the difference in phase is related to
the direction of target travel. These returned echo signals
are a very low level. The Preamplifier and
Programmable Gain Amplifier stages increase the signal
levels.
The signals are then converted from analog to digital by
the A/D converter. This digital signal stream is feed to
the Digital Signal Processor (DSP). The DSP transforms
the data to the frequency domain, where the data is
analyzed and processed to find valid targets.
To become a valid target the signals must meet the
criteria setup by the user for target directionality and
speed limitations. The DSP will convert the speed of the
valid targets into the unit of measure set by the user and
output the RS232 data via the serial port.