Monitoring the system temperature of the various receivers

april,2002

The plots:
    Tsys polA, polB
    Tsys PolA - TsysPolB
    The system temperature of each receiver is measured each day by the operators using the correlator. The telescope is normally sitting at 10 deg za and an azimuth of 270 (although it occasionally may be at a different az,za). The cal is flipped on/off once a second 3 times. The total power is used to compute the cal deflection and then Tsys. There are up to 8 different kinds of cals using 2 diodes on each receiver. The high cals are:

high uncorrelated cal with 2 diodes (diode1->polA,diode2->polB)

high correlated cal with 1 diode (diode1->polA,diode1->polB)

high uncorrelated cal with crossover (diode2->polA,diode1->polB)

high correlated cal with 90 deg phase shift (diode2->polA,diode2_90degphase shift->polB)

There is a similar set of low cals (that go through a 10 db coupler). The table below shows the receiver name, frequency range of the receiver, frequency where the system temperature is measured, and the cals that are available.

For alfa a slightly different method is used:

there is only 1 cal
the cal is winked at a 20 hz rate for 3 seconds.
Tsys is computed over the upper 1375-1525 Mhz band

receiver cals and frequency of measurement
receiver	freq. range Mhz	cals	freq. (Mhz) of measurement
327	312-347	1 correlated cal	327
430	425-435	all 8 cals	431
800	700-800	1 correlated cal	740
lbw	1120-1730	all 8 cals	1400
alfa	1220-1520	1 correlated	1375-1520
sbw	1800-3100	all 8 cals	2290
sbn	2330-2430	1 correlated cal	2380
sbh	3000-4000	all 8 cals	3500
cband	3850-6000	all 8 cals	5000
xband	8000-10000	all 8 cals	8800

There is a daily ascii output that is stored in the control room. An sample ouput looks like:

line0: Thu Jan 1 16:19:47 2004 az/za lst: 270.0004 10.0000 22:36:05
line1: rcv 5 1400.0 6 3 0 if1 -40.78 -40.17 if2 -54.59 -54.28 cor 0.91 0.94 11 11
line2: 5 hcal 9.550 9.810 27.8 27.2

col descriptions

line 0 columns line 0 col descriptions

Thu Jan 1 16:19:47 2004 date

270.0004 10.0000 22:36:05 azimuth, zenith angle, lst when data was taken.

line 1 columns line 1 col descriptions

rcv 5 receiver numbers:
1-327,2-430,3=610,5-lbw,6-lbn,7-lbw,9-cband,11-xband,12-sbn

1400.0 frequency in Mhz where the data was taken

6 bandwidth number: 2-25,3-12.5,4-6.25,5-3.125,6-1.5...

3 integration time in seconds for cal

0 lbw hybrid. 0 out, 1 in

if1 -40.78 -40.17

pwr dbm measured with upstairs power meter.
-40 is optimal for lbw,lbn,sbn
-32 is optimal for cband,sbw,xband,
430,327 can have less (say -48) since they are narrower bands.

if2 -54.59 -54.28 power in dbm from the downstairs power meter.

cor 0.91 0.94 correlator 0 lag pola,polB. This is the ratio of measured to optimum power.
If the value is far from 1 then the power levels were wrong (say 20%)

11 11 The attenuator values used at the correlator (polA,polB)
The attenutaors go 0 to 15 db

line 2 columns line 2 col descriptions

5 receiver number

hcal

H is high cal, L is lowCal, D1 is diode 1,D2 is diode2
H/Lcal: uncorrelated cal (two diodes) D1->pola,D2->polB
L/Lxcal: uncorrelated cross over (two diodes) D1->polB,D2->polB
H/Lcorcal: correlated cal (one diode). D1->polA,D1->polB
H/L90cal: correlate 90deg phaseshift cal. D2->polA,D2+90deg->polB

9.550 9.810 Calvalue in kelvins used (polA,polB)

27.8 27.2 Tsys computed in kelvins (polA,polB

**col descriptions**
line 0 columns	line 0 col descriptions
Thu Jan 1 16:19:47 2004	date
270.0004 10.0000 22:36:05	azimuth, zenith angle, lst when data was taken.
line 1 columns	line 1 col descriptions
rcv 5	receiver numbers: 1-327,2-430,3=610,5-lbw,6-lbn,7-lbw,9-cband,11-xband,12-sbn
1400.0	frequency in Mhz where the data was taken
6	bandwidth number: 2-25,3-12.5,4-6.25,5-3.125,6-1.5...
3	integration time in seconds for cal
0	lbw hybrid. 0 out, 1 in
if1 -40.78 -40.17	pwr dbm measured with upstairs power meter. -40 is optimal for lbw,lbn,sbn -32 is optimal for cband,sbw,xband, 430,327 can have less (say -48) since they are narrower bands.
if2 -54.59 -54.28	power in dbm from the downstairs power meter.
cor 0.91 0.94	correlator 0 lag pola,polB. This is the ratio of measured to optimum power. If the value is far from 1 then the power levels were wrong (say 20%)
11 11	The attenuator values used at the correlator (polA,polB) The attenutaors go 0 to 15 db
line 2 columns	line 2 col descriptions
5	receiver number
hcal	H is high cal, L is lowCal, D1 is diode 1,D2 is diode2 H/Lcal: uncorrelated cal (two diodes) D1->pola,D2->polB L/Lxcal: uncorrelated cross over (two diodes) D1->polB,D2->polB H/Lcorcal: correlated cal (one diode). D1->polA,D1->polB H/L90cal: correlate 90deg phaseshift cal. D2->polA,D2+90deg->polB
9.550 9.810	Calvalue in kelvins used (polA,polB)
27.8 27.2	Tsys computed in kelvins (polA,polB

The plots:

There are now 2 sets of tsys plots. The first set shows Tsys versus date . The second set shows the difference TsysPolA - TsyspolB.

Tsys Vs date:

These plots are updated at 3 am each morning. There is a set for the last 30 days, the year to date, and for previous years. For those receivers with multiple cals, only the high cals are plotted. Pol A is the solid line while pol B is the dashed line. The tsys from each cal type is plotted in a different color.

tsys last 5 days

tsys last 30 days

alfa tsys by month. user data

Tsys for the various receivers by year
	327,800	gr430,ch430	lbw	alfa	sbn,sbw	sbh,cband	cbh,xband
YearToDate	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf
2012	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf
2011	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf
2010	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf
2009	327,800	gr430,ch430	lbw	.ps .pdf	sbn,sbw	sbh,cband	cbh,xband
2008	327,610	gr430,ch430	lbw		sbn,sbw	sbh,cband	cbh,xband
2007	327,610	gr430,ch430	lbw		sbn,sbw	sbh,cband	cbh,xband
2006	327,610	gr430,ch430	lbw		sbn,sbw	sbh,cband	cbh,xband
2005	327,610	gr430,ch430	lbw		sbn,sbw	sbh,cband	cbh,xband
2004	327,430,610		lbw,lbn		sbn,sbw	sbh,cband	cbh,xband
2003	327,430,610		lbw,lbn		sbn,sbw	sbh,cband	xband
2002	327,430,610		lbw,lbn		sbn,sbw	sbh,cband	xband
2001	327,430,610		lbw,lbn		sbn,sbw	cband	xband
2000	327,430,610		lbw,lbn		sbn,sbw	cband
1999	430,610		lbw,lbn		sbn,sbw	cband

TsysPolA - TsysPolB:

Each plot has:

TOP: the median Tsys (over all non zero cals) for polA (Black) and polB (red)
BOTTOM: TsysPolA - TsysPolB

The difference plots show receiver variation more clearly than the Tsys plots. Some of these differences could be attributed to polarized power from the sky for the linearly polarized feeds. The circularly polarized feeds (430, sbn, xb) should not be affected by linearly polarized power. The plots are made by year. For the current year they are updated at 3am daily. For each pol, Tsys is the median of all non-zero cal measurements (hcal,hcorcal,hxcal, etc..).

The system temperature is taken daily and then recorded. If the cals are changed, then it may take awhile for the new cal values to be measured. So there may be periods of time when old cal values are being used on new cal diodes. When the new cal values are installed , you could see a jump in the system temperature. You should be able to identify these jumps by going to the cal values page and looking to see when the new cal values were installed. Gradual drifts in TsysA-TsysB are probably problems with the cal diodes drifting.

TsysPolA -TsysPolB by Rcvr and Year

year 327 430gr 430ch 800
lbw alfa
sbn sbw sbh cb cbh xb

2013 .ps .pdf .ps .pdf .ps .pdf .ps .pdf .ps .pdf .ps .pdf
.ps .pdf .ps .pdf
.ps .pdf .ps .pdf .ps .pdf

2012 .ps .pdf .ps .pdf .ps .pdf .ps .pdf .ps .pdf .ps .pdf
.ps .pdf .ps .pdf
.ps .pdf .ps .pdf .ps .pdf

2011 .ps .pdf .ps .pdf .ps .pdf .ps .pdf .ps .pdf .ps .pdf
.ps .pdf .ps .pdf
.ps .pdf
.ps .pdf

2010 .ps .pdf .ps .pdf .ps .pdf .ps .pdf .ps .pdf .ps .pdf
.ps .pdf .ps .pdf
.ps .pdf .ps .pdf .ps .pdf

2009 .ps .pdf .ps .pdf .ps .pdf .ps .pdf .ps .pdf
.ps .pdf .ps .pdf
.ps .pdf .ps .pdf
.ps .pdf

2008 .ps .pdf .ps .pdf .ps .pdf
.ps .pdf
.ps .pdf .ps .pdf
.ps .pdf
.ps .pdf

2007 .ps .pdf .ps .pdf .ps .pdf .ps .pdf .ps .pdf
.ps .pdf .ps .pdf .ps .pdf .ps .pdf .ps .pdf .ps .pdf

2006 .ps .pdf .ps .pdf .ps .pdf .ps .pdf .ps .pdf
.ps .pdf .ps .pdf .ps .pdf .ps .pdf .ps .pdf .ps .pdf

2005 .ps .pdf .ps .pdf .ps .pdf .ps .pdf .ps .pdf
.ps .pdf .ps .pdf .ps .pdf .ps .pdf .ps .pdf .ps .pdf

2004 .ps .pdf .ps .pdf .ps .pdf .ps .pdf
.ps .pdf .ps .pdf .ps .pdf .ps .pdf .ps .pdf .ps .pdf

2003 .ps .pdf .ps .pdf .ps .pdf .ps .pdf
.ps .pdf .ps .pdf .ps .pdf .ps .pdf .ps .pdf

2002 .ps .pdf .ps .pdf .ps .pdf .ps .pdf
.ps .pdf .ps .pdf .ps .pdf .ps .pdf .ps .pdf

**TsysPolA -TsysPolB by Rcvr and Year**
year	327	430gr	430ch	800	lbw	alfa	sbn	sbw	sbh	cb	cbh	xb
2013	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf		.ps .pdf	.ps .pdf	.ps .pdf
2012	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf		.ps .pdf	.ps .pdf	.ps .pdf
2011	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf		.ps .pdf		.ps .pdf
2010	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf		.ps .pdf	.ps .pdf	.ps .pdf
2009	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf		.ps .pdf	.ps .pdf		.ps .pdf	.ps .pdf	.ps .pdf
2008	.ps .pdf	.ps .pdf	.ps .pdf		.ps .pdf		.ps .pdf	.ps .pdf		.ps .pdf		.ps .pdf
2007	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf		.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf
2006	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf		.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf
2005	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf		.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf
2004	.ps .pdf	.ps .pdf		.ps .pdf	.ps .pdf		.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf
2003	.ps .pdf	.ps .pdf		.ps .pdf	.ps .pdf		.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf		.ps .pdf
2002	.ps .pdf	.ps .pdf		.ps .pdf	.ps .pdf		.ps .pdf	.ps .pdf	.ps .pdf	.ps .pdf		.ps .pdf

notes:

2010:

06oct10. added plots for alfa. created postscript and pdf files.
30sep10 alfa thermally cycled. caused 6b to go bad. 2a tsys back to normal (at least for awhile).
nov10: cband. first part. gortex cover fell off mouth of the horn, moisture got in the horn. replaced around 19nov10.

2006

31aug06: lbw new cal values (measured back in 06jul06 installed). The cal jump occurred 16jun06 when the dewar was warmed up and a loose cal cable was found.
28aug06: cband new cal values (measured back in 06jul06) installed. Switch cband to use all cals again.
05jun06: cband switched Tsys measurement to use h90cal. So both pola and polB are being measured using diode 2.
19jul06: 430 polB Tsys increased. Stayed high till about 10aug06. The jenning relay for polB was bad.
25may06: cband Found sma connector for calPolA was lose. This caused the jump back in 02feb06. It was tightened. Looks like this changed the cal value. It did not jump back to the pre 02feb06 values.
02feb06: cband: diode A temp jumped up by about 3 K. Since they tsys's above are medians of all cals measurements, it looks like both pols jumped.

2005

06dec05: lbw moved tsys freq 1400-> 1405 to move off of the resonance in polA (more Info).
28nov05: installed new cal values for lbw (new diodes were installed).
27sep05: updated cal values for 430ch. changed by about 6%.
18aug05: sbw cal cables changed. need to recalibrate cals.
08aug05: cband cal values now correct (for hcorcal,hxcal polB).
30jul05: installed cband calvalues (but hcorcal, hxcal polB had a bug in them). Correction made 08aug05.
22jul05: lbw diode 1 dies. Switched so all the Tsys measurements use diode 2. So just look at h90cal,l90cal for the correct tsys values.
01jun05: warmed up lbw dewar. found loose/broken polA rf cable at probes and cracked polB cal cable in dewar. Fixed the cables.
25may05: new cb amps, cals.. New cal values not installed until 08aug05.

2004

12sep04: installed new cal values for lbw.
18jul04: sbw new cal values installed (new diodes were installed 14may04)
18mar04: new cal values for xband installed.
14mar04: new cal values installed (new diodes were installed 13feb04)
23feb04: cbh. moved frequency 7000-> 7050 to get off of resonance.
12feb04: cbh cal values installed.

2003

27oct03 installed xband cal values that were measured on the hill.
14oct03 reversed stubs on sbn turnstile. Also flipped cables out of dewar. Swithed whixh pol was using coldest amp.
10oct03 installed sbw cal values.
21jul03 installed new xb cals from sky/absorber measurments.
30may03 recomputed xband cals using correct def of 0cal,90cal,etc
18may03 installed new cband calvalues
14may03 updated sbh calvalues .they had been drifting
22apr03 new cal diodes on cb installed (not yet calibrated.
01apr03 lbw cals for new receiver calibrated and installed

2002

04apr02 sbw -updated hcorcal to be measured value from absorber cal measurement sep01. other cal values unchanged

06apr02 lbw - left vacumn pump running on lbw dewar. 70K temp went 120=>80K Tsys dropped by a view degrees . must be a leak in the dewar.

11jul02 - lbn cals values changed. Tsys jumped.

processing: x101/tsys/monitor/tsysmondaily.pro, tsysmonyears.pro

 home_~phil