User manual
Code: ENIGMA III User Manual
Edition: 1 Revision: 4
Date: 19/12/2008
Page: 9/97
1 Introduction
History of GAMIC SDP Processors
1995 GSP01 PC Card for non Doppler Low-Cost Applications
1996 GSP02 Stand alone Doppler Signal Processor
1997 ENIGMA I First generation of high performance video baseband Doppler Processor. Up to 2
MAIN boards (3 DSP's) and 3 Expansion boards (8 DSP's) each
1998 ENIGMA II High performance Digital IF Doppler Signal Processor Receiver. Up to 2 MAIN
boards (6 DSP's) and 3 Expansion boards (8 DSP's) each.
2003 ENIGMA III High Performance FPGA / Linux host based dual polarization IF Doppler Signal
Receiver. Signal processor algorithm run on a LINUX based host computer.
The ENIGMA III Signal Processor consists of two main modules. The IF-Digitizer (IFD) and the Signal
Processor host computer. The host computer is basically a Linux based standard inidustrial PC. ENIGMA
III performs two main tasks:
● Digital Receiver Functions to obtain I, Q and Burst Pulse statistics. This processing is done on the
IFD and includes matched-filtering and extraction of dynamic "I" and "Q" values. In addition,
burst pulse is analyzed with respect to frequency, phase and amplitude to provide digital phase
locking, AFC and advanced processing and control features not present in traditional radar's.
● Weather Information extraction to obtain Intensity, Velocity and spectral width and dual
polarization moments like ZDR, LDR, KDP, PHIDP and RHOHV. This operation include Doppler
and Intensity processing to extract the calibrated reflectivity, the mean velocity and spectrum
width. Clutter filtering by Doppler filtering in the time- or frequency- domain, thresholding and
velocity unfolding by dual PRF.
The IF Digitizer Module is housed in a sealed box. The main purpose is to digitize the analog IF signals
with a minimum of additional computational effort. The fiber optic link ensures the galvanic isolation of
the IF Digitizer Module from the rest of the digital components, thus avoiding additional ground loops
and other stray effects. Note, that the "Uplink" serial coaxial cable is isolated as well from the IF
Digitizer Module. Due to this technique, distances up to 100 meters between the IF Digitizer module and
the signalprocessor can be realized.
GAMIC Proprietary