K5 VSSP Sysytem Manual

fx_cor_new

DESCRIPTION
SYNOPSIS

DESCRIPTION

"fx_cor_new" is an FX-type software correlator supporting a variety of data formats, such as Mark5B, Mark5(Mark-IV, VLBA), VDIF, ADS, OCTAD, RAW besides K5/VSSP, and carries out cross correlation processing using an apriori file. Correlated data are output to a file with a "cout" format.
Ver.2019-11-20 and after supports multi-thread VDIF data consisting of single-channel/thread.

SYNOPSIS

[Type 1]

fx_cor_new afile [options]

afile	a-priori file name created by "apri_calc"
OPTIONS
--version	show program version
--help	show how to execute
-integ integration_time	set integration period (sec). Default is a scheduled scan period.
-coffset clock_offset	set clock offset (sec) applied for fringe search purpose. Positive value menas Y clock tic earlier than X clock tic. Default is 0.0
-crate clock_rate	set clock rate (s/s) difference between X and Y station clock applied for fringe search purpose. Default is 0.0
-soffset start_offset	set start time offset (integer sec). Default is 0.
-t1pp t1pp	set unit integration period (parameter period) (sec) for correlation processing. Default is BT1PP in "cor_head.h" (usually 1)
-pp_nosync	turns off the synchronization mode of PP (parameter period) (default is that PP synchronize to second tic)
-lag lagsize	set the size of delay lag window. lagsize can be 16, 32, 64, 128, 256, 512, .. Default is DELAYSIZE in cor_head.h
-pmode pmode	set plot device mode. 0 : XWINDOW (env PGDISP can change PGPLOT display device) and PostScript file (pgplot.ps or gnuplot.ps) out (dfault) 1 : PostScript file (pgplot.ps or gnuplot.ps) out only 2 : XWINDOW only -1 : no graphic output
-comment "any_comment"
	set comment appeared in a correlation function plot when pmode=0,1,2
-nopcal	suppress PCAL (phase calibration) signal detection
-pchx1 ch1	define pickup chanel# as CH# 1 of X data (Ver.2018-12-17 or later)
-pchx2 ch2	define pickup chanel# as CH# 2 of X data
.........
-pchx16 ch16	define pickup chanel# as CH# 16 of X data
-pchy1 ch1	define pickup chanel# as CH# 1 of Y data (Ver.2018-12-17 or later)
-pchy2 ch2	define pickup chanel# as CH# 2 of Y data
.........
-pchy16 ch16	define pickup chanel# as CH# 16 of Y data
-ch1 ch1Y	define Y channel for X CH# 1 (default 1).
-ch2 ch2Y	define Y channel for X CH# 2 (default 2).
.........
-ch16 ch16Y	define Y channel for X CH# 16 (default 16).
-orule naming_rule	set naming rule of output file name 0 : use program default (cout.txt) 1 : coutNNNNtxt (deflt) where NNNN is 4 digit serial number 2 : coutEXP_CODE/coutYYDDDNNNNXYG.txt
	where EXP_CODE -- experiment code YY -- 2 digit year DDD -- 3 digit day of year NNNN -- 4 digit scan number XY -- baseline id (2 char or 4 char) G -- Frequency group (a\|b\|c\|d) 3 : coutYYDDDNNNNXYG.txt
	where YY -- 2 digit year DDD -- 3 digit day of year NNNN -- 4 digit scan number XY -- baseline id (2 char or 4 char) G -- Frequency group (a\|b\|c\|d) (default is COUT_NAMING_RULE in cor_head.h)
-odir outdir	set output file directory. System default is environmental variable K5COUT. If K5COUT is not defined, program default defined by COUTDFLT in "cor_head.h" is used (usually "../cout").
-rfoffset rf_offset	set RF frequency difference between Y and X (RFy-RFx)(Hz)
-cout cout_file	set output file name compulsory. If this parameter is set, naming rule and out directory are ignored.
-frstep frstep	set fringe phase calculation step in samples 0: automatic calculation 1: every 1 sample 8: every 8 samples N: every N samples. (Note: N can be any number, but 1000/N must be integer) default is FRSTEP_FX_COR (in cor_head.h)
-frauto	set frstep=0 (automatic calculation mode)
-fall pcalf	set PCAL frequency of all channels compulsory (kHz)
-f1 pcalf1	set CH1 PCAL frequency compulsory(kHz)
-f2 pcalf2	set CH2 PCAL frequency compulsory(kHz)(kHz)
................
-f16 pcalf16	set CH16 PCAL frequency compulsory(kHz)(kHz)
-iq2r	If this option is set, I/Q data are converted to real data at first, then correlated (default: correlation without conversion)
-sdelay	execute "sdelay" after correlation processing (search function are displayed instead of correlation function)
=== options below are dedicated to fx cor and fx cor new ===
-modefr modefr	set fringe stopping approximation mode 0: no approximation (exact calculation) 9: 9 level approximation (default) 2: 2 level approximation 3: 3 level approximation
-hanning	use Hanning lag window
-hamming	use Hamming lag window
-bpf flow:fhigh[:fact][,flow:fhigh[:fact][,flow:fhigh[:fact][,.....]]]
	set BPF lower and higher frequencies flow -- BPF lower cut off frequency in a video band (MHz) fhigh -- BPF higher cut off frequency in a video band (MHz) fact -- factor (0.0-1.0), default is 1.0
-bpf2 fc:bw[:fact][,fc:[bw][:fact][,fc:[bw]:fact][,.....]]]
	set BPF parameters fc -- BPF center frequency in a video band (MHz) bw --- pass band width (MHz) fact -- factor (0.0-1.0), default is 1.0
-fres fres	set frequency resolution (MHz) (deflt 0.0 means AUTO)
-delpcal ch#:fs[:fi][,ch#:fs[:fi][,....]]]}
	set PCAL signal frequencies to reject by channel ch# -- channel number (starting from 1) fs -- lowest frequency of PCAL signals in baseband (MHz) fi -- interval of PCAL signals (MHz)
	frequencies of PCAL signals removed are fs, fs+fi, fs+2fi, fs+3fi, ... when fi is omitted, only fs is removed
	bandwidth of rejection filter is double the resolution of FFT. this can be changed by option `-pcalbw' below
or
-delpcal delpcal_file	set file name which describes PCAL signal rejection information
-pcalbw bwmhz	set bandwidth of PCAL rejection filter (MHz)
	default bandwidth is double the resolution of FFT
-e2bit mode	set 2-bit decoding method for X and Y data
-e2bitx mode	set 2-bit decoding method for X data
-e2bity mode	set 2-bit decoding method for Y data
	where mode is 0: default 1: (0, 1, 2, 3) offset binary (VDIF default) 2: (0, 2, 1, 3) Mark-5B default 3: (1, 0, 2, 3) singed integer Note: This option is valid for VDIF or Mark-5B data
=== options below are for Ver.2020-05-27 and after ===
-pulsar period:duty:phase_ch1[,phase_ch2[ .... ]]
	set Plusar gate parameters at X station period -- pulsar period (sec) duty -- duty ratio (0.0-1.0) phase_ch1 -- phase of pulsar gate at reference time for ch1(deg) phase_ch2 -- for ch2 if phase is omitted, set by ch1's phase
-prt_pulsar HH:MM:SS	set reference time for pulsar gate (default is PRT of apriori values)
=== options below are for Ver.2020-07-30 and after ===
-nodm	disable dispersion correction mode described in an a-priori file
-nopulsar	disable pulsar mode described in an a-priori file
-new_method	use coherence spectrum method for correlation processing
-coh[erence]	same as '-new_method'
-plspp	set PP length to the same as the pulsar period. When this option is set, '-coh' is also set automatically.
-frmid	make reference frequency for fringe stopping to the middle of baseband width (default is baseband RF frequency)

Contents of file set by the option -delpcal delpcal_file is as follows

        *** PCAL signal rejection filter file  ***
        **    for option '-delpcal' of fx_cor_new
        **
        **    usage   -delpcal DELPCAL.txt
        **
        **  Format Ver. 2019-08-27
        **
        **    ch#  sFreq(MHz) intFreq(MHz)
        **      where
        **        ch#  :  channel # (starting from 1)
        **                0 means for all channel
        **        sFreq  :  lowest PCAL frequency in channel (MHz)
        **        intFreq  :  interval of PCAL signal (MHz)
        **       Note-- rejected PCAL frequency is sFreq, sFreq+intFreq, sFreq+2*intFreq, ....
        **    [example]
        **      ch#  sFreq(MHz)   intFreq (MHz)  
        **       0     0.01          5.0
        **      set for all channel same parameter
        **
        **      or
        **      1      1.4           5.0
        **      2      8.4           5.0
        **      3      2.4           5.0
        **      4      4.4           5.0
        **      set different start frequency for every channel
        **
        **
        *  CH#  sFreq(MHz)  intFreq(MHz)   
            1     0.4          5.0
            2     3.4          5.0
            3     4.4          5.0
            4     0.4          5.0
            5     4.4          5.0
            6     1.4          5.0
            7     4.4          5.0
            8     2.4          5.0
        *

An example of pulsar mode parameters in an a-priori file.


        $PULSAR_GATE
        1.3373:0.06:215@04:15:00    ** period:duty:phase@HH:MM:SS  if HH:MM:SS is omitted PRT is used instead

        $PULSAR_DM      ** dispersion correction parameters
        **Type-1
        DM= 12.43       **  Dispersion Measure (pc/cm^3)
        frf= 316.0      **  reference RF frequency (MHz)
        phs0= 218.0     **  phase at frf (deg)
        dphs0= 11.0     **  pulse width (deg)
        
        **Type-2
        *f1=  0.0       ** band lowest frequency (MHz)
        *f2= 16.0       ** band edge frequency (MHz)
        *phs1= 218.0    ** phs1 parameter (deg)
        *phs2= 204.0    ** phs2 parameter (deg)
        *dphs= 11.0     ** Delta phs (deg)

===== t1pp allowed for less than 1 sec is as follows ====
(this is due to the algorythm)

t1pp
fsampl 0.01 0.02 0.04 0.05 0.1 0.2 0.5
40kHz X OK OK X OK OK OK
100kHz X X OK X X OK X
200kHz X OK OK X OK OK OK
500kHz X X OK X X OK X
1MHz X OK OK X OK OK OK
2MHz OK OK OK OK OK OK OK
4MHz OK OK OK OK OK OK OK
8MHz OK OK OK OK OK OK OK
16MHz OK OK OK OK OK OK OK
32MHz OK OK OK OK OK OK OK

[Type 2]

fx_cor_new afile [sekibun [soffset [coffset [crate [t1pp [smode [pp_mode [lag_size [tzoom [pmode [comment]]]]]]]]]]]

afile	a-priori file name created by "apri_calc"
sekibun	integration period (sec). Default is a scheduled scan period.
soffset	start time offset (integer sec). Default is 0.
coffset	clock offset (sec)
crate	clock rate offset (s/s)
t1pp	unit integration period (parameter period) (sec)
smode	search mode 0: Wide 1: Mid 2:Narrow (default 2) (no more use)
pp_mode	PP synchronization mode 0: synchronized to second tic (default) 1: not synchronized to second tic
lag_size	lag window size. 16,32,64,128,256,512,.. 0 means lag_size set to DELAYSIZE in "cor_head.h"
tzoom	time axis zoom ratio in graphics (int) 0 : full scale (default) as same as 1 -VE : Max position is automatically centered
pmode	plot device selection 0: XWINDOW (env PGDISP can change PGPLOT display device) and PostScript file (pgplot.ps or gnuplot.ps) out (default) 1: PostScript file (pgplot.ps or gnuplot.ps) out only 2: XWINDOW only -1: No graphic output
comment	comment appeared in a correlation function plot

[Monitoring Environmental Variables]

fx_cor_new env

check environmental variables used in "fx_cor_new"

K5APRIDIR -- default directory for apriori file
K5COUT -- default directory for correlation data out
PGDISP -- PGPLOT display device name when plot

Updated on August 13, 2020

	t1pp
fsampl	0.01	0.02	0.04	0.05	0.1	0.2	0.5
40kHz	X	OK	OK	X	OK	OK	OK
100kHz	X	X	OK	X	X	OK	X
200kHz	X	OK	OK	X	OK	OK	OK
500kHz	X	X	OK	X	X	OK	X
1MHz	X	OK	OK	X	OK	OK	OK
2MHz	OK	OK	OK	OK	OK	OK	OK
4MHz	OK	OK	OK	OK	OK	OK	OK
8MHz	OK	OK	OK	OK	OK	OK	OK
16MHz	OK	OK	OK	OK	OK	OK	OK
32MHz	OK	OK	OK	OK	OK	OK	OK