1. Set up on asteroid with an LRS2-B DirectACAM setup (using coordinates from ephemerides close to the current time).
2. Run script "nst.py" to offset fiducial on active guider to compensate for target's motion
This requires giving as an input the JPL HORIZONS ephemerides for that night, with timestamps and RA/Dec coordinates:
354_eleonora_20231228_simple.txt
Tonight we ran the script with 1 minute updates, and a simple interpolation scheme was used to determine each differential offset.
After the exposure sequence was complete we took another ACQ camera image to verify the target was still in (roughly) the same place. Below are the before and after ACQ camera images:
Below are animations of all of the guider frames taken during the observation. Guider 1 was active, and its fiducial was offset throughout:
| Guider
1 |
Guider
2 |
 |
 |
Below are the reconstructed LRS2-B images taken during this observation. Nine exposures of 90s each were taken:
The centroids in the LRS2-B IFU coordinates (0,0 is center) were:
[INFO - 2023-12-28 18:36:22,962] multi_20231228_0000008_exp01_orange.fits Centroid: -0.26 1.15 [INFO - 2023-12-28 18:36:35,501] multi_20231228_0000008_exp02_orange.fits Centroid: -0.23 1.00 [INFO - 2023-12-28 18:36:48,038] multi_20231228_0000008_exp03_orange.fits Centroid: -0.17 1.06 [INFO - 2023-12-28 18:37:00,570] multi_20231228_0000008_exp04_orange.fits Centroid: -0.17 1.01 [INFO - 2023-12-28 18:37:13,127] multi_20231228_0000008_exp05_orange.fits Centroid: -0.01 1.14 [INFO - 2023-12-28 18:37:25,681] multi_20231228_0000008_exp06_orange.fits Centroid: 0.03 1.12 [INFO - 2023-12-28 18:37:38,230] multi_20231228_0000008_exp07_orange.fits Centroid: 0.09 1.18 [INFO - 2023-12-28 18:37:50,786] multi_20231228_0000008_exp08_orange.fits Centroid: 0.11 1.17 [INFO - 2023-12-28 18:38:03,345] multi_20231228_0000008_exp09_orange.fits Centroid: 0.05 0.59
So there was a small systematic drift in X of ~0.3", and no obvious drift in Y.
Testing on the night of Dec 28 2023 (2023-12-29 UT)
We observed Ganymede satellite of Jupiter) for about 45
minutes, taking a series of 60 exposures with HPF; first we
used Guider 1 and second we used Guider 2. This was the
procedure:
1. Set up on Ganymede with an HPFACAM setup, using coordinates
from ephemerides close to the current time.
2. Run script "nst.py"
to offset fiducial on active guider to compensate for target's
motion
This requires giving as an input the
JPL HORIZONS ephemerides for that night, with timestamps and
RA/Dec coordinates:
ganymede_20231229_simple.txt
Tonight we ran the script with 1
minute updates, and a simple interpolation scheme was used to
determine each differential offset.
We did this once using Guider 1 and immediately again using
Guider 2, to see if there were any differences. The delivered
SNR on HPF appears to be consistent with a well-centered
target throughout the exposures.
guiding (and offsetting) with GC1:
Start Estart End
IQ Dimm
SkySBrt Trans pIllum
C.E. SNR Guide Corr
04:18 04:25
04:26 1.37
0.79 16.68 0.82
0.42
0.34 571 0.25+/-0.11
04:26 04:27
04:28 1.27
0.76 16.72 0.86
0.45
0.39 581 0.27+/-0.06
04:28 04:29
04:30 1.32
0.91 16.59 0.85
0.47
0.40 579 0.24+/-0.08
04:30 04:30
04:31 1.31
0.86 16.59 0.84
0.49
0.41 574 0.25+/-0.10
04:31 04:32
04:33 1.36
0.91 16.61 0.87
0.51
0.45 586 0.27+/-0.11
04:33 04:34
04:35 1.44
1.07 16.69 0.89
0.55
0.48 591 0.27+/-0.12
04:35 04:35
04:36 1.46
0.97 16.71 0.91
0.56
0.51 598 0.29+/-0.12
04:36 04:37
04:38 1.51
0.93 16.71 0.92
0.60
0.55 612 0.25+/-0.12
04:38 04:39
04:40 1.55
1.40 16.68 0.91
0.64
0.58 613 0.32+/-0.15
04:40 04:40
04:41 1.50
0.94 16.67 0.91
0.66
0.60 638 0.31+/-0.13
guiding (and offsetting) with GC2:
Start Estart End
IQ Dimm
SkySBrt Trans pIllum
C.E. SNR Guide Corr
04:41
04:47 04:48
1.47 0.94
17.53 0.78
0.84 0.65
621 0.30+/-0.12
04:48 04:49
04:50 1.63
1.10 17.56 0.77
0.88
0.68 578 0.34+/-0.18
04:50 04:50
04:51 1.61
1.02 17.59 0.77
0.88
0.68 603 0.34+/-0.21
04:51 04:52
04:53 1.44
0.99 17.59 0.76
0.84
0.64 612 0.26+/-0.13
04:53 04:53
04:55 1.53
1.00 17.57 0.76
0.80
0.61 582 0.27+/-0.14
04:55 04:55
04:56 1.57
1.30 17.55 0.76
0.75
0.57 572 0.27+/-0.13
04:56 04:57
04:58 1.50
1.11 17.54 0.75
0.68
0.51 576 0.29+/-0.10
04:58 04:58
04:59 1.52
1.25 17.54 0.75
0.65
0.49 549 0.31+/-0.10
04:59 05:00
05:01 1.65
1.50 17.50 0.75
0.59
0.44 542 0.29+/-0.13
05:01 05:01
05:03 1.65
1.26 17.54 0.73
0.54
0.39 522 0.28+/-0.11