2019 Oct (c192)

Report, regarding the poor performace of the VLBA in this session:

Description of special processing applied to P3 (Pico Veleta DBBC3) data in this session:

Stations	Obs time [hrs]	total volume [TB] @4Gbps	Recording
VLBA	39	36	Mark6
Ys, On, Mk, Eb	38 +2	36	local & etransfer
Pv	38 +2	36	Mark6
KVN	36	32.5	local & etransfer
GLT	45	40.5	Mark6

assuming a duty cycle of 50%.

Project Code	Block Code	Sources	DOYS	UT	Freq	Stations	Status	PI	Comment
	F192A		276		86360 MHz	Ef, On, O6, Ys, Mh, Pv ,P3	done	n/a	fringe check
MC004	C192A	1803+784	276-277	18:30-04:30	86360 MHz	Ef, On, Ys, Mh, Pv, P3, VLBA, GLT, KVN	correlation finished, data released to PI	CUI
MM017A, MB011B	C192B	FERMI sources	277-278	04:30-07:30	86360 MHz	Ef, On, Ys, Mh, Pv, P3, VLBA, GLT, KVN	correlation finished, data released to PI	MARSCHER	C192B and MM017A coinside except for 2013+370 (277:1445-1701) data used for MB011B too.
MB011B	C192C	Cygnus A	278-279	13:15-09:30	86360 MHz	Ef, On, Ys, Mh, Pv, P3, VLBA, GLT, KVN	correlation finished, data released to PI	BACH

Ys has switched the IF configuration with c192b from using A/C to A/B. The first affected scan is no0053. The change was done due to a faulty calibration of board C which led to lower amplitudes in LCP prior to the change.
"Normal" Pico Veleta PV (DBBC2) data was recorded with wrong polarization setup for most of the session (during C192A, C192B and the first quarter of C192C parts both polarization channels recorded RCP and LCP was completely lost). That's why the main production correlation was done with DBBC3 data in 16 32 MHz band mode rather than usual 8 64 MHz per pol. Because DBBC3 is still in the comissioning stage, certain hardware problems were detected -- phase instability and small amplitude insonsistencies for different boards. To compensate this, additional per band delay corrections were applied during the correlation, see details here.

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