July 13 TCS3 Engineering (Denault, Griep )
Goals
TCS3 pointing run. (2nd half of night, 12am-6am)
Note: Scheduled TCS pointing run this afternoon at the techgroup meeting, so was not
able to do work during the day (Clean/inspect gears/encoders; Encoder Measurement).
1. Encoder Measurement
started at about 00:22
goto zenith
ape.set.pmac
(Opps, used MP with 1800 as/s velocity - next time use 1000 as/s)
Recorded error APE-encoder error while taking data HA encoder ratios:
HA_hrs Err_HA_DEC(as)
0 -0.3
-1 3.7
-2 19.6
-4 57.8
0 -4.9
+1 -6.6
+2 -12.3
+4 -23.0 -24.5 (noticed DEC APE-Encoder error, started recording it here)
0 -18.2 -0.2
Recorded error APE-encoder error while taking Dec encoder ratios data:
(this time recording both HA and DEC errors).
DEC_deg Err_HA_DEC(as)
20 -18.2 -2.0
5 -18.2 -2.2
-10 -18.1 7.4
-40 -18.1 25.0
20 -18.2 -0.5
35 -18.2 11.7
50 -18.2 13.1
60 -18.2 13.3
20 -18.3 5.3
Save data as: r-100114.dat
Data and Log can be view at: http://irtfweb.ifa.hawaii.edu/~tcs3/tcs3/data/encoders/
Will not changes to TCS3 encoder rations, just a measurement today.
Next time record both HA and DEC error. Noticed Dec Ape-encoder errors as HA moves:
Just a quick measurement at -1.5 and +1.5 hr to confirm:
HA_hrs Err_HA_DEC(as)
0 -18.0 5.3
-1.5 -8.7 4.3
+1.5 -27.2 -0.1
0 -27.2 7.2
2. benchmark1
Check telescope setup:
spex in the middle.
chopper is on and centered.
apes.set.pmac to zero encoders.
filename is b1.dat
pattern benchmark 13
start tracking & initialize pointing
Tony recording pmac following error range to check servo tracking performance:
b1_star ferr_range StdDev
1 0.151 0.035
2 0.267 0.054
3 0.262 0.049
4 0.350 0.054
5 0.181 0.032
6 0.275 0.048
7 0.265 0.050
8 0.315 0.046
9 0.183 0.033
10 0.321 0.058
11 0.215 0.043
12 0.185 0.033
Resulting benchmark data files:
tpoint file: b1.dat
.ape file: b1.ape
3. Take Pointing Data
Starting at: 1:49am
Goto Zenith, stop and Ape.Set.PMAC
filename: pointing.dat
Pattern: Grid
Sep: 14 (give 60 starts).
Dave finished taking data at 2:55am
At zenith ape - encoder is: -42.1 17.2
tpoint file: pointing.dat
.ape file: pointing.ape
Used tpoint to get new coefficients:
tpoint_log.dat - log of tpoint session.
pointing.ps
pointing.pdf - tpoint graphs (postscript and PDF)
pointing_coeff.txt - resulting coefficients.
Sky RMS = 16.22
Updated .tcs-init with new coefficients
die, and restarted TCS to read new .tcs-init file.
4. benchmark2
Check telescope setup:
apes.set.pmac to zero encoders.
filename is b2.dat
pattern benchmark 13
start tracking & initialize pointing
Looked like Dave's 1st star ob b2.dat was the wrong star.
(deleted 1 point from .dat file)
tpoint file: b2.dat
.ape file: b2.ape
5. b1 vs b2
Look at the 2 benchmarks
Here is a graph of HA error of b1.dat vs b2.dat
gnuplot to make the graphs:
plot 'b1.ape' using 10 with linespoints title 'b1 HA pt.madj'
replot 'b2.ape' using 10 with linespoints title 'b2 HA pt.madj'
Here is a graph of DEC error of b1.dat vs b2.dat
gnuplot to make the graphs:
plot 'b1.ape' using 11 with linespoints title 'b1 Dec pt.madj'
replot 'b2.ape' using 11 with linespoints title 'b2 Dec pt.madj'
HA show improvement (b2 line is flatter).
Dec is (maybe) a little bit worse.
Will keep the new pointing coefficients.
Finished at 04:13am.
6. Follow up
TCS Servo Tracking not so good, only 4/12 sample below 0.200 (none below 0.150)
Follow up with EW; need to see if we can improve performace of TCS.
Dave indicated that the spex cross hairs position is near the north edge of the field of view.
(10 arcsec below TOP). It actually is out of the field-of-view for cshell.
Dave suggest we redefine the IN position in smokey to -30 Dec of it current position.
Tony if improve TCS3 logging to show amount of correction after a slew (to monitor
pointing map's performance)
Maybe replace map_total with corr ha dec to .ape to show amount to peak up on after slews.