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Code: ENIGMA III User Manual

Edition: 1 Revision: 4

Date: 19/12/2008

Page: 1/97

ENIGMA III

User Manual

GAMIC Proprietary

Summary of content (97 pages)

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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 1/97 ENIGMA III User Manual GAMIC Proprietary
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 2/97 Table of Contents 1 Introduction........................................................................................................................... .......................9 2 Algorithms................................................................................................................................. .................10 2.1 Thresholding........................................................................
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 3/97 6.1.5 KlystronTaperingStopX........................................................................................................... ...42 6.1.6 KlystronWindowTypeStartX........................................................................................... ...........42 6.1.7 KlystronWindowTypeStopX..................................................................................... .................42 6.2 Trigger.........
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 4/97 6.11.4 FilterDelay............................................................................................................. ...................60 6.11.5 MaxFilterRange........................................................................................................ ................60 6.12 Measured offsets....................................................................................................................
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 5/97 7.9.1 ZdrOffset................................................................................................................................... ..71 7.9.2 LdrOffset................................................................................................................................... ..71 7.9.3 PhidpOffset...............................................................................................................
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 6/97 9.2 Electrical specification.................................................................................................... ...................89 9.2.1 Input voltage................................................................................................................. ..............89 9.2.2 Input Downlink...............................................................................................................
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 7/97 Illustration Index Illustration 1: Spectrum showing clutter and weather................................................................... ...............14 Illustration 2: Time domain filtered spectrum....................................................................... .......................14 Illustration 3: Frequency domain filtered spectrum.................................................................................
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 8/97 EDITION REVISION DATE Modification Object 1 0 22/11/2007 First Edition by mt 1 1 20/06/2008 vk - Added DualPolMode, AFCSettings, thresholdFlagsTable, ZeroFilter, gasAttenuation - Added: noisesample, sampleburst, setafcmode - Ray data format 1 2 06/10/2008 mt – – 1 3 09/10/2008 Minor text revisions Added trigger, coho, sector blanking and extended dynamic range parameter mt New error code 1 4 19/12/2008 s
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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.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 10/97 2 Algorithms 2.1 Thresholding As the radar signal is contaminated with noise it is important to apply thresholding to the radar data. Thresholding means that bins that pass one or the combination of several tests are discarded and flagged as invalid. A combination of the following thresholds can be applied to all physical moments. The combination of the flags is stored in a binary bit mask.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 11/97 2.1.1 Noise Power threshold The Noise Power threshold [dB] is related to the noise floor measured through noise sampling and is applied to reflectivity data. Typically, the noise threshold is 1 dB above the noise floor. Parameter: NOISEThreshold 2.1.2 CCOR threshold The clutter power threshold [dB] is compared to the clutter power, obtained from the 4.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 12/97 2.1.6 Adjusting reflectivity thresholds Uncorrected reflectivity data (UZ) is not corrected for clutter. In order to compare the influence of threshold adjustments for corrected reflectivity data (CZ), open two A-Scopes or PPI's. One for uncorrected reflectivity and one for corrected reflectivity. 2.1.6.1 NOISE Threshold Parameter This threshold [dB] rejects corrected reflectivity data, which is n dB above the noise floor.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 13/97 When using the frequency domain filtering (FFT and DFT mode) Interpolation or Dual Slope Interpolation should be used. These filters do not affect weather targets overlapped by clutter ● Set CCOR threshold to –30 dB. ● Select Clutter Micro Suppression Threshold (30-40dB) if you are using range sampling ● Select IQ clutter filter to IQ3. ● Select NOISE | CCOR for CZ threshold flags.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 14/97 2.1.6.3 Clutter filtering examples Consider the following example. The spectrum shows the combination of a strong clutter target and weather. Illustration 1: Spectrum showing clutter and weather The same weather situation with time domain clutter filter applied. The clutter peak is attenuated by 40dB but still is ~40dB above noise. The weather echo around zero velocity also was strongly attenuated.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 15/97 Illustration 5: PPI-Z Pulse Pair Processing Illustration 4: PPI-V pulse Pair Processing In the above shown examples the clutter has been removed by time domain filtering. They show strong attenuation in the weather at zero velocities. Illustration 7: PPI-Z DFT Processing Illustration 6: PPI-V DFT Processing The same weather situation using frequency domain filtering.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 16/97 The ENIGMA III signal processor has the capability to output CCOR as moment. The two following images show the CCOR moment (Clutter Power) recorded with different clutter filter algorithms.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 17/97 2.1.7 Adjusting velocity thresholds Open an A-Scope or a PPI for radial velocity (V) and observe the effects of the following parameter. 2.1.7.1 SQI Threshold Parameter The SQI threshold parameter can be adjusted from 0 to 1. 0 is a signal, containing only noise, whereas 1 is a „pure“ tone signal. Typically this threshold is set to 0.4..0.5, depending on the signal quality.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 18/97 ● Select SQI for V threshold flags. ● Select IQ clutter All pass. ● Click on Apply. ● Now, you will see a very noisy A-Scope for the radial velocity. Increase the SQI threshold to 0.4. The noise in the A-Scope almost disappears. Fine-tune the SQI parameter, until the noise is almost removed completely. 2.1.7.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 19/97 2.1.8 Adjusting spectral width thresholds The thresholding of spectral width data is the same as for radial velocity. See description above. 2.2 Reflectivity and Doppler speckle remover Speckle removers can be applied to all final physical moments (Z, UZ, V, W). They can be switched on or off separately for reflectivity and Doppler results. Speckle removers identify isolated valid bins in the output data ray.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 20/97 2.3 Averaging The SDP configuration parameter include the range sample and time sample parameter. Note, sometimes “range sample” is also referred to “range averaging” and time sample is also referred to “time averaging”. The figure below explains both parameters. The number of time samples is equivalent to the number of pulses, which are used for averaging.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 21/97 2.4 Doppler clutter filters Doppler clutter filtering is based on the valid assumption that stationary ground targets appear as strong narrow peaks around zero in the spectrum (sampled over the PRT). Illustration 13: Typical spectrum showing weather and clutter targets The doppler clutter filter (both time- and frequency- domain processing) attenuate the radar signal around the zero frequencies.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 22/97 Illustration 14: 40 dB IIR clutter filter Illustration 15: 50 dB IIR clutter filter The figure below shows the digital clutter filter structure for the time domain filtering. The coefficients determine the filter characteristics. Seven different high pass filter are selectable. Please refer to the chapter Pulse Pair processing, DFT processing and FFT processing for further details.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 23/97 2.4.2 Frequency domain filtering For frequency domain filtering several different algorithms have been implemented the algorithm can be chosen with the parameter InterpolationMode. 2.4.2.1 DC Cancelation This is the simplest frequency domain filter. It is basically a highpass filter (like the timedomain IIR filter) with infinite stopband attenuation.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 24/97 2.4.2.1 Windowing To suppress sidelobes it is necessary to apply a tapering window to the data prior to the transformation into the frequency domain. Window functions generally have a maximum value centered on the time series and are tapered near zero at the ends. This tapering reduces the spectrum smearing a leakage of spectral energy introduced by the discontinuity imposed by sampling when the end points are joined.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 25/97 Terminology: • • • • N represents the width, in samples, of a discrete-time window function. Typically it is an integer power-of-2, such as 210 = 1024. n is an integer, with values 0<=n<=N-1. So these are the time-shifted forms of the windows: w(n)=w 0(n-(N-1)/2) , where w(n) is maximum at n=0. Some of these forms have an overall width of N−1, which makes them zero-valued at n=0 and n=N−1.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 26/97 2.5 Pulse-pair processing. The basis for time domain moment estimation is the transform relationship of the autocorrelation function of the complex signal to the power spectrum.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 27/97 2.6 DFT processing. The Doppler power spectrum may be estimated from the Discrete Fourier Transform (DFT) of the complex signal.The DFT decomposes the observed data into a sum of sinusoids having amplitude and phase that will exactly reproduce the observed data.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 28/97 2.7 FFT processing. The above described DFT (Discrete Fourier Transform) processing needs a lot of CPU resources. In case the DFT processing can't manage the acquired data, some optimizations can be used. DFT works on the number of samples being a power of 2 faster than on an arbitrary number of samples.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 29/97 2.8 Range-Doppler Dilemma The physical relationship between the unambiguous range and unambiguous velocity limits the dynamics of the acquired data. An example is shown in the diagram below. The unambiguous velocity can be increased with the staggered PRF algorithm.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 30/97 2.9 Calibration Calibrated reflectivity data [dBZ] are calculated from the meteorological radar equation. Illustration 22: Radar equation Please refer to the FrogRT user manual for more details about calibration and how to perform it.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 31/97 Illustration 23: Definition of radar losses 2.10 Dynamic Angle Syncing Dynamic angle syncing mode is used for data acquisition. One ray consist of the number of pulses which fall in one angle sector.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 32/97 Illustration 25: Integrated pulses versus PRF and scanrate 2.11 Dual PRF Unfolding In order to increase the mean velocity dynamic range, the dual PRF unfolding algorithm (= staggered PRF ) has been implemented.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 33/97 Illustration 26: Dual PRF unfolding Parameter: PrfLimits and PrfTab GAMIC Proprietary
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 34/97 2.12 Default values for the extended SDP parameter Default values for the extended parameters can be obtained from the table below, but keep in mind, that optimal values can only be obtained by adjusting each parameter according to the specific requirements. Each site needs different parameter for optimum performance.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 35/97 3 Network Network is configured in the file /etc/conf.d/net. The file looks as follows. Here a static IP address or DHCP can be configured. Just comment out the corresponding lines. /etc/conf.d/net: # To avoid delay on booting, use the fixed address configuration # and comment out the dhcp/fallback part # Static IP address #config_eth0=( "192.168.3.11 netmask 255.255.255.0" ) #route_eth0=( "default via 192.168.3.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 36/97 5.1 Command interface SDP is controlled by text commands via network session.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 37/97 5.1.1 Connection 5.1.1.1 Browser interface Most of the parameters described in the following section also can be accessed through a comprehensive HTTP interface. Just point your browser at the IP address of the ENIGMA3 signal processor giving the port number 30000 Example: http://enigma3.gamic.com:30000 5.1.1.2 Telnet SDP listens on TCP port 5555. Frog-Muran software connects as a TCP client to this port.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 38/97 6 Parametrization There are many commands and parameters supported by the SDP.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 39/97 DataFormat: Frog output data format type DualPolMode: dual polarization mode ElevationAbsoluteOffset: calibratiobn offset for antenna alignment ElevationSynchroOffset: calibratiobn offset for encoder/synchro diference FFTWindow: Type of smoothing window for FFT and DFT ACF algorithms FIRCoeff0: FIR coefficients for pulse 0 FIRCoeff1: FIR coefficients for pulse 1 FIRCoeff2: FIR coefficients for pulse 2 FIRCoeff3: FIR coefficient
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 40/97 SpeckleRemoverZ: Reflectivity speckle remover SyncModeParam: Sync mode TagConfiguration: Serial TAGS configuration Trig0Duration: Tigger 0 duration Trig0Enable: Tigger 0 enable/disable Trig0Invert: Tigger 0 invert Trig0Start: Tigger 0 start Trig1Duration: Tigger 1 duration Trig1Enable: Tigger 1 enable/disable Trig1Invert: Tigger 1 invert Trig1Start: Tigger 1 start UDPTagsHost: host that sends tags in UDP UDPTagsPort: localhostp
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 41/97 if failed 6.1 Klystron related parameter The following parameter can be configured for a Klystron system: 1) These parameter are only available if SDPType equals 13 2) After setting the parameters the command setpulsewidth has to be called (it will perform the calculation of the burst coefficients and upload them to the COHO card) 3) The ENIGMA host PC must be equipped with the COHO card option. 6.1.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 42/97 6.1.4 KlystronTaperingStartX Tapering percentage for the start of the burst (0...100% 100% means that the tapering is performed from the start of the burst up to the middle of the burst). X represents the pulse width index (0-3). After setting the parameters the command setpulsewidth has to be called (it will perform the calculation of the burst coefficients and upload them to the COHO card) Type: Default: Unit: float 0 % 6.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 43/97 matching the burst exactly in time and 25% of linear tapering at both sides of the burst (25% tapering for a burst duration of 1µs means tapering for 0.5µs * 0.25 = 0.125µs) set KlystronGateDuration0 1 set KlystronGateStart0 0 set KlystronPulseDuration0 1 set KlystronTaperingStart0 25 set KlystronTaperingStop0 25 set KlystronWindowTypeStart0 0 set KlystronWindowTypeStop0 0 setpulsewidth 0 6.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 44/97 6.2.4 TrigXInvert Invert the trigger (When this trigger is disabled the output stays in a low state, regardles of the content of this parameter. Type: Default: boolean false 6.3 Sector blanking Sector blanking is configured through a azimuth versus elevation table providing a 1° resolution in azimuth and a 0.5° resolution in elevation. The azimuth range is obviously 360° and the elevation range is from -5° to 45°. 6.3.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 45/97 Example: Configure sector blanking for a sector 10°-16° azimuth for elevation -5° to 3°.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 46/97 Remark: Only the baud rate is configurable. The other serial parameter are fixed. 1 stop bit. 1 start bit and no parity will be used. 6.4.2 IFDTagBaudRate Specify the baudrate for the RS422 TAG input at the ENIGMA IFD+. The ENIGMA IFD III+ provides an additional input for the serial angle tags The baudrate can be specified directly in baud (1200...4000000) and can also be a “non-standard” value like 500000 (500kbits/s).
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 47/97 The last Byte consists of a checksum calculated from Byte 0 to byte 5 (CSUM6-CSUM0).
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 48/97 D7 0 D6 CSUM6 D5 CSUM5 D4 CSUM4 D3 CSUM3 D2 CSUM2 D1 CSUM1 D0 CSUM0 Data packet Format 1 6 Bytes are transmitted. First Byte is a frame syncing Byte (MSB=1). Byte 0 – Byte 4 contain 16 bit azimuth and elevation information: AZ15 (MSB) - AZ0 (LSB) EL15 (MSB) - EL0 (LSB) The last Byte consists of a checksum calculated from Byte 0 to byte 4 (CSUM6-CSUM0).
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 49/97 Byte 4 D7 0 D6 EL8 D5 EL7 D4 EL6 D3 EL5 D2 EL4 D1 EL3 D0 EL2 Byte 5 D7 0 D6 CSUM6 D5 CSUM5 D4 CSUM4 D3 CSUM3 D2 CSUM2 D1 CSUM1 D0 CSUM0 6.5 Extended Dynamic Range In single polarization mode the ENIGMA IFD has the ability to stack two converters (Build 100 or above). The low channel is connected to the horizontal input and the high channel is connected to the vertical input.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 50/97 Default: Unit: 70 percent 6.5.3 PowerDiffH/PowerDiffV Set the power difference between low and high channel in dBfor horizontal and vertical channel. Type: Default: Unit: float 0 dB Calibration procedure, see below. 3) The phase difference between the low and the high channel (coupler + cable) 6.5.4 PhaseDiffH/PhaseDiffV Set the phase difference between low and high channel in degree for horizontal and vertical channel.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 51/97 Here ENIGMA measured a power difference of 20.3 dB. The next step is to set this value: set PowerDiffH 20.3 Now issue the getadcdiff command again. getadcdiff getadcdiff errormsg=null phaseDiffH=123.7 phaseDiffV=0 powerDiffH=0.013 powerDiffV=0 You see that the power difference now is effectively calibrated to 0 (with a very small residual error). Now you can calibrate the phase difference by issuing: set PhaseDiffH 123.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 52/97 6.6.2 IFD matched filter The batched filter for the IFD is a complex bandpass filter. The bandwidth of the passband has to be matched to the pulse width. Example: For a pulse width of 1µs you will need a bandwidth of 1Mhz For a pulse width of 2µs you will need a bandwidth of 500kHz The matched filter is implemented as a complex (symmetric) FIR filter.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 53/97 performs undersampling of the IF signal. Please refer to common literature for further explanations about bandpass theory and band limited signals. 2. Assuming a IF frequency of 30 MHz the IF sampling frequency (76.8 MHz) fulfills the Nyquist criterion and there is no frequency folding. The lowpass filter needs to be mixed up to the IF frequency of 30 MHz. 6.6.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 54/97 2. This multiple of the decimation factor must be in the range [1...20] 3. The decimation factor limits the minimal range gating. As a rule of thumb: Smallest range gate possible is “decimation factor” * 2m. In other words. If you want a minimum range gating of 25 m the decimation factor must not be larger than 12 (which leads to 12*20=240 coefficients maximum which leads to a filter length in time of 3.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 55/97 attenuation weight decimation dataRate scalingShiftFactor Remark: - Stopband attenuation in dB for Remez algorithm (used by Frog only) - Weighting for Remez algorithm (used by Frog only) - Decimation factor (see remark) - obsolete (set to 0) - obsolete (set to 1) The values used by the Frog software only can be set to fixed values. The number of coefficients must always be a multiple of the decimation factor.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 56/97 GAMIC Proprietary
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 57/97 6.7 Video signal processing Time series consist of an array of complex numbers sn=In+jQn I and Q signals are sampled with configurable resolution. Standard is multiple of 25m but can be changed to any integer step in meter on user request.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 58/97 6.9.1 RangeStep Specify the range step as floating point value in km. The range step must be a multiple of the base resultion (25 m). Range stepping specifies the bin spacing for range sampling (see: RangeSample) Type: Default: Unit: float 0.125 km 6.10 Range Sampling The algorithm uses 'Range', 'RangeStep' and 'RangeSample' parameters to average autocorrelations by range.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 59/97 6.11 ClutterFilter Specify the clutter filter number. This value is used for Pulse Pair Processing , as well as for the FFT/DFT processing. Possible values depend on selected autocorrelation algorithm ('AcfMode' parameter), see corresponding 'Processing' sections. The larger the filter number is, the stronger filter is applied. 0 means 'no filter'. Type: Default: integer 1 6.11.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 60/97 6.11.3 ZeroFilter Clear IIR filter for every ray Type: Default: boolean false 6.11.4 FilterDelay Number of pulses to be discarded after filter zeroing (The recursive filter needs to be filled with data in order to stabilize) Type: Default: integer 0 6.11.5 MaxFilterRange The selected filter (which number is 'ClutterFilter') is applied up to the specified range in km. Type: Default: Unit: float 100.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 61/97 6.12 Measured offsets 6.12.1 IOffsetH Inphase noise sampling average on horizontal channel. The value is subtracted from the 'I' data of the input time samples. It is calculated by noise sample procedure, stored in Frog-Muran software and set by it. Type: Default: float 0.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 62/97 Type: Default: float 0.0 Remark: The offsets are only used for lowpass receivers (video processing) as the A/D converter offset is effectively canceled by the matched bandpass filter. 6.13 PRFTable Format of argument: staggering prf1 prf2 ... prf8 If staggering=0, only prf1 is used, otherwise dual PRF mode is used. Eight PRF values are reserved for four pulse widths.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 63/97 Unit: dB 6.15.1 noisePowerH Noise power on horizontal channel as measured by the noisesample command. Type: Default: float 0.0 6.15.2 noisePowerV Noise power on vertical channel asmeasured by the noisesample command. Type: Default: float 0.0 6.16 dbz0 Horizontal/vertical calibration reflectivity for 4 pulse widths.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 64/97 6.18 gasAttenuation Gaseous attenuation constant. a*r is the gaseous attenuation. 'r' is the range in km, 'a' is an attenuation factor. It can be set by parameter 'gasAttenuation'. Parameter 'RangeNorm' enables/disables range correction. Type: Default: Unit: float 0.0 dB/km 6.19 CCORThreshold Negative value in dB for CCOR thresholding. Type: Default: Unit: float -10.0 dB 6.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 65/97 Default: false 6.21.2 RainAttenuation_a Parameter 'a' of the rain attenuation correction formula. Type: Default: float 0.0044 6.21.3 RainAttenuation_b Parameter 'b' of the rain attenuation correction formula. Type: Default: float 1.17 6.21.4 RainAttenuation_A Parameter 'A of the rain attenuation correction formula. Type: Default: float 200.0 6.21.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 66/97 6.22 Threshold algorithms. Enigma III generates the following moments: ● Reflectivity Z ● Velocity V ● Spectrum width W ● Uncorrected reflectivity U There are four threshold checking algorithms in Enigma III: ● CCOR ● SQI ● RHOHV ● NOISE These algorithms can be combined using boolean functions AND and OR. Internally, Enigma III checks above thresholds and creates a value that describes the results.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 67/97 6.22.1 thresholdFlagsTable Format of the argument: "word0 word1 ... word15". Type: Every word is a 16 bit unsigned decimal. Default: 65535 in every word (means 'All pass') Remark: Use the EnigmaThresholdFlagCalculator tool to obtain the bit values 6.22.2 Speckle removal Speckle filter removes isolated bins in the ray. Filters are enabled separetaly for reflectivety Z and velocity V by the following parameters: 6.22.2.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 68/97 7.2 Reflectivity. The corrected reflectivity is calculated by the formula: Z =SNR dBZ 020⋅log r a⋅rCCOR A R where: SNR is a signal-to-noise ratio, calculated by the formula: SNR=10⋅log T 0−N  ; N T0 is calculated in the autocorrelation algorithm. The noise power N is calculated in the noise sampling procedure or in the adaptive noise sampling algorithm.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 69/97 It is normalized to the Nyquist interval [-1;1]. Phase unfolding is performed in dual-PRF mode using PRFs ratio.Supported values are 2:3, 3:4 and 4:5. 7.6 Acquisition parameter Acquired data are available over the separate TCP connection. SDP listens on the port 5556 for incoming connection. Only one is established at the time. Some parameters configure the transmission of the acquired data. 7.6.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 70/97 7.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 71/97 7.9.1 ZdrOffset The bias in the horizontal/vertical receiver path needs to be calibrated in order to get a ZDR reading of zero for the first range gate. The corresponding parameter is ZDROffset. Type: Default: Unit: float 0 dB 7.9.2 LdrOffset The bias in the horizontal/vertical receiver path needs to be calibrated in order to get a LDR reading of zero for the first range gate. The corresponding parameter is LDROffset.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 72/97 ● 2 - Log,I,Q 8 bit ● 3 - I,Q 16 bit ● 4 - SQI/CCOR 8 bit ● 5 - Power spectrum ● 6 - Moments 16 bit ● 7 - Full moments 16 bit In dual pol mode: ● 0 – Angle data ● 1 – Moments 8 bit ● 2 – Log,I,Q 8 bit ● 3 – I,Q 16 bit ● 4 – SQI/CCOR 8 bit ● 5 – Power spectrum ● 6 – Horizontal LDR mode moments 8 bit ● 7 – Moments 16 bit ● 8 – Horizontal LDR mode moments 16 bit ● 9 – Full Moments 16 bit ● 10 – Ful
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 73/97 Ray header has the same format for all modes. Then 'N' ray bins follow. Amount of bins is calculated by the formula: N=Range/(RangeStep*RangeSample) Format of the bin depends on the 'DataFormat' and 'DualPolMode' parameters.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 74/97 7.11.1 Ray header format. All values have network byte order.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 75/97 7.11.1.1 SDPFlags WORD 0: 15 14 13 12 11 10 9 8 7 6 5 4 3 2 AM0 AM1 AM2 PWR FIFO UL AFC DL UL FIFO PWR AM0-AM2 1 DL AFC 1 if AFC locked 1 if IFD downlink ok 1 if IFD uplink ok 1 if PCI-Receiver card FIFO ok 1 if IFD power supply ok 3 bit encoding the AFC mode 0 – AFC 1 – MFC 2 – AFC Search 3 – MFC Hold 4 – AFC Hold Words 1-5 are reserved 7.11.1.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 76/97 7.11.2 Angle Data No bins are sent, only ray header 7.11.3 Moments In single polarization mode: Moment Mapped range of values Size in bytes Threshold Z [-32;95.5] dBZ 1 Yes V [-1;1] 1 Yes U [-32;95.5] dBZ 1 Yes W [0;1] In dual polarization mode: 1 Yes Moment Mapped range of values Size in bytes Threshold ZH [-32;95.5] dBZ 1 Yes VH [-1;1] 1 Yes UH [-32;95.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 77/97 Moment Mapped range of values Size in bytes Threshold I [-32767,32768] ADU 1 No Q [-32767,32768] ADU 1 No MAG [0, 32768] ADU 1 No dummy n/a In dual polarization mode: 1 No Moment Mapped range of values Size in bytes Threshold IH [-32767,32768] ADU 1 No QH [-32767,32768] ADU 1 No MAGH [0, 32768] ADU 1 No IV [-32767,32768] ADU 1 No QV [-32767,32768] ADU 1 No MAGV [0, 32768] ADU 1 No
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 78/97 SQI [0,1] 1 No CCOR [-90,0] dB In dual polarization mode: 1 No Moment Mapped range of values Size in bytes Threshold SQIH [0,1] 1 No CCORH [-90,0] dB 1 No SQIV [0,1] 1 No CCORV [-90,0] dB 1 No 7.11.7 Power spectrum Amount of bins in this mode equals to number of pulses to sample, stored int 'SyncModeParam'. The DC component is in the middle ofbin series.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 79/97 Moment Mapped range of values Size in bytes Threshold Z [-64;128] dBZ 2 Yes V [-1;1] 2 Yes U [-64;128] dBZ 2 Yes W [0;1] 2 Yes In dual polarization mode Moment Mapped range of values Size in bytes Threshold ZH [-64;128] dBZ 2 Yes VH [-1;1] 2 Yes UH [-64;128] dBZ 2 Yes WH [0;1] 2 Yes ZV [-64;128] dBZ 2 Yes VV [-1;1] 2 Yes UV [-64;128] dBZ 2 Yes WV [0;1] 2 Yes PHIDP [-180;1
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 80/97 SQI [0,1] 2 No CCOR [-90,0] dB 2 No SNR [0,250] dB 2 No In dual polarization mode Moment Mapped range of values Size in bytes Threshold ZH [-64;128] dBZ 2 Yes VH [-1;1] 2 Yes UH [-64;128] dBZ 2 Yes WH [0;1] 2 Yes ZV [-64;128] dBZ 2 Yes VV [-1;1] 2 Yes UV [-64;128] dBZ 2 Yes WV [0;1] 2 Yes PHIDP [-180;180] ° 2 Yes ZDR [-32;32] dB 2 Yes KDP [-20;20] °/km 2 Yes RHOHV [0;
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 81/97 V [-1;1] 2 Yes U [-64;128] dBZ 2 Yes W [0;1] 2 Yes LDR [-64;0] dB 2 Yes 7.11.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 82/97 8 Commands Most of the commands can only be performed when the data acquisition is stopped (See commands stopacq and startacq). Keep in mind that this will corrupt any running schedulers as the direct command interface bypasses the scheduler and the running Frog software. When operating the ENIGMA signalprocessor with the Frog/MURAN software it is virtually never necessary to perform any of these commands manually. 8.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 83/97 8.2.2 getantennaspeed get antenna params. Returns: azspeed azimuth speed, deg/s elspeed elevation speed, deg/s 8.2.3 gettemperature Temperature in degrees, zero means not available.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 84/97 8.2.5 getconverter Converter status.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 85/97 8.3 getversion Returns version numbers of hardware protocol and firmware versions for DSP and FPGAs. Output: protocol - HW communication protocol, unsigned dsp - PCI DSP firmware version,unsigned fpgaPci - PCI FPGA firmware version, unsigned fpgaIfd - IFD FPGA firmware version, unsigned software - ENIGMA software version, unsigned 8.4 sampleburst Get burst samples centered around t=0.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 86/97 8.7 settxdtrigger Enable/disable transmitter trigger Parameter: 0 – Disable trigger, 1- Enable trigger 8.8 geterrorconditions Get the internal errors from the PCI-Receiver card. The command resets all errors.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 87/97 8.11 save Save parameter to configuration file. The configuration files are located in /opt/enigma3. The parameter are stored in the file controlagent_X.is (with X corresponding to SDPType) 8.12 quit End the current telnet session.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 88/97 9 Specifications 9.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 89/97 9.2 Electrical specification 9.2.1 Input voltage 220-240 Volt AC, 50-60 Hz, Measured Power consumption : Expected maximum Power consumption : 9.2.2 Input Downlink Connector Type : Simplex Fibre, female 9.2.3 Output Uplink Connector Type : SMA, female 9.2.4 Output Trigger Connector Type : SMA, female 5 Volt buffered 50 Ohm 9.2.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 90/97 9.2.6 Input Elevation TAG parallel Connector Type: 25 SUBD, female, 16 bit TTL PIN PIN PIN PIN PIN PIN PIN PIN PIN PIN PIN PIN PIN PIN PIN PIN 1: 2: 3: 4: 5: 6: 7: 8: 9: 10: 11: 12: 13: 14: 15: 16: PIN 23: PIN 24: PIN 25: EL0 (LSB) EL1 EL2 EL3 EL4 EL5 EL6 EL7 EL8 EL9 EL10 EL11 EL12 EL13 EL14 EL15 (MSB = 180 degree) GND GND GND 9.2.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 91/97 Technical specification - Single Polarization 9.3.1 ENIGMA III IF DIGITIZER (IFD) IF Receiver inputs 3 channel, horizontal, vertical and reference IF frequency 30 MHz or 60 MHz ( other frequencies optional) IF Dynamic range > 100 dB ( 2 us pulse width) ADC Sampling frequency 76.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 92/97 9.3.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 93/97 FFT and DFT - Adaptive filter width adjustable in 8 steps (Allpass, Filter 1-7) - Range adjustable 1-400km - Clutter micro suppression - Selectable interpolation: - DC cancelation - Half plane subtraction - Interpolation - Dual slope interpolation - Selectable tapering window - Rectangle - Hamming - Blackman - Hann - Welch - Kaiser-Bessel Time averaging Adjustable time samples (8-256) or Dynamic angle syncing (0.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 94/97 Status information - Host CPU load, CPU temperature and amount of free memory - Host Voltages - IFD power supply - IFD temperatures - A/D converter status - AFC Status - Number of pulses for autocorrelation PCI receiver card Standard PCI card.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 95/97 10 Maintenance and firmware update 10.1 Enigma III host update To upgrade DSP programs do following: 1. Type “/etc/init.d/muran stop” to stop the running Frog Muran system. 2. Type “ssh root@enigma3 /etc/init.d/enigma3 stop” to login into ENIGMA signalprocessor 3. Enter password when prompted” WARNING: Enigma software MUST be stopped before upgrading the firmware 4. Type “cat newfile.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 96/97 8. Start the Frog/Muran system on the radar computer by calling “/etc/init.d/muran start” 10.3 Antenna alignment As part of the installation of a radar system, the antenna has to be leveled and aligned to true north. Usually this is done mechanically. The ENIGMA III signalprocessor has the ability to correct the azimuth and elevation TAGS. The parameter AzimuthAbsoluteOffset and ElevationAbsoluteOffset are used for this.
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Code: ENIGMA III User Manual Edition: 1 Revision: 4 Date: 19/12/2008 Page: 97/97 10.5 IQ Recording Recording of the I/Q-data of the PCI-receiver-board in full resolution in configurable ring-buffer on the signal-processing PC Open a console and type: ● telnet enigma3 5555 ● auth Secondary ● set RecordName ‘filename’ ● set RecorderMode 1 Remark: filename is the user given filename for the recorded data. The command “set RecorderMode 1” starts the recording.