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Hubble Space Telescope
Same Visit, No Rotation, No Shift

1: Introduction

In this series of tests, we tested the performance of WFC3/UVIS instrument distortion coefficient table (IDCTAB) uab1537bi_idc.fits. This IDCTAB contains uniquely computed distortion solutions for 10 filters: F225W, F275W, F336W, F390W, F438W, F555W, F606W, F775W, F814W, and F850LP. All other filters use the values for F606W. NOTE: On many of the below plots, the name of the IDCTAB used is "210710_uvis_idc.fits". This was the final version of our internal development UVIS IDCTAB. It is functionally identical to the public version (uab1537bi_idc.fits) available from CDBS.

In order to test each of the unique distortion solutions, observations of Omega Centari were obtained using each of the above filters. Observations from each of the 9 filters (with the exception of F606W) were then run through the testing pipeline using the F606W observation as a common comparison image for all filters.

This test was designed to test the overall performance of the IDCTAB across the entire UVIS frame. To best accomplish this, all observations were of the exact same star field with the same orientation. All observations from the same visit, ensuring that they all used the same guide star pair, and thus ensuring that all observations had the same rotation angle. Additionally, all observations had no X or Y POSTRG shift, ensuring that each image would have as close as technically possible to identical pointing. Additional details of the observations used for this test can be found in the summary table below.

Summary of Relevant Observation Information
RootnameProposal IDTarget NameFilterExposure TimeDate of ObservationOrientatX PostargY PostargRA PostargDEC Postarg
ibc301r3q11911OMEGACENF225W900.0000002010-01-14149.76834716448960.0000000.0000002.016928333333E+02-4.747905555556E+01
ibc301qtq11911OMEGACENF275W800.0000002010-01-14149.76834716448970.0000000.0000002.016928333333E+02-4.747905555556E+01
ibc301r5s11911OMEGACENF336W350.0000002010-01-14149.76834716448970.0000000.0000002.016928333333E+02-4.747905555556E+01
ibc301qsq11911OMEGACENF390W350.0000002010-01-14149.76834716448960.0000000.0000002.016928333333E+02-4.747905555556E+01
ibc301qxq11911OMEGACENF438W350.0000002010-01-14149.76834716448970.0000000.0000002.016928333333E+02-4.747905555556E+01
ibc301r1q11911OMEGACENF555W40.0000002010-01-14149.76834716448960.0000000.0000002.016928333333E+02-4.747905555556E+01
ibc301qrq11911OMEGACENF606W40.0000002010-01-14149.76834716448970.0000000.0000002.016928333333E+02-4.747905555556E+01
ibc301qvq11911OMEGACENF775W350.0000002010-01-14149.76834716448970.0000000.0000002.016928333333E+02-4.747905555556E+01
ibc301qzq11911OMEGACENF814W40.0000002010-01-14149.76834716448970.0000000.0000002.016928333333E+02-4.747905555556E+01
ibc301r2q11911OMEGACENF850LP60.0000002010-01-14149.76834716448970.0000000.0000002.016928333333E+02-4.747905555556E+01

2: Iteration I

Iteration I Statistics Computed From Binned Vector Plots
FilterX RMSY RMSVec Mag RMSVec Mag MeanVec Mag MedianVec Mag MaxVec Mag Min
F225W 0.0619962 0.0799640 0.0729046 0.414755 0.420163 0.572061 0.243324
F275W 0.0684033 0.0840516 0.0712326 0.290559 0.289562 0.424837 0.144157
F336W 0.0685186 0.0838137 0.0679479 0.680144 0.682581 0.821008 0.521642
F390W 0.0249672 0.0121938 0.0149579 0.556296 0.557046 0.591691 0.517113
F438W 0.0185060 0.0138604 0.0116932 0.574387 0.574843 0.612367 0.547629
F555W 0.0313975 0.0325450 0.0242913 0.659950 0.655559 0.709812 0.613024
F775W 0.0217711 0.0157910 0.0159262 1.51582 1.51607 1.56603 1.46957
F814W 0.0349570 0.0420476 0.0392870 0.510480 0.516866 0.584848 0.424169
F850LP 0.0182667 0.0245401 0.0251670 0.821576 0.816819 0.879236 0.758678

F225W/F606W

F275W/F606W

F336W/F606W

F390W/F606W

F438W/F606W

F555W/F606W

F775W/F606W

F814W/F606W

F850LP/F606W

Shift.dat parameters by Filter
FilterX ShiftY ShiftRotationScale
F225W -0.1780956 -0.3608039 0.00110 0.9999447
F275W -0.2312911 -0.1405816 0.00142 0.9999414
F336W -0.5110167 0.4319654 -0.00101 0.9999397
F390W -0.2746292 0.4835491 3e-05 1.000012
F438W 0.1131694 0.5621193 -2.99999e-05 1.000006
F555W 0.2233824 0.6194127 0.00078 0.9999928
F775W -0.224978 1.498771 0.00004 1.000006
F814W 0.1603998 0.4809996 0.00007 1.000031
F850LP -0.07888682 0.8186609 0.00036 0.9999994

NOTE: In the above table, shift values are in units of drizzled image pixels, rotation values are in units of degrees, and scale values are dimensionless multipliers.

3: Iteration II

Iteration II Statistics Computed From Binned Vector Plots
FilterX RMSY RMSVec Mag RMSVec Mag MeanVec Mag MedianVec Mag MaxVec Mag Min
F225W 0.0164916 0.0144976 0.00997484 0.0196000 0.0190870 0.0614640 0.00143544
F275W 0.0137171 0.0102873 0.00839626 0.0151886 0.0138314 0.0579532 0.00144451
F336W 0.0145234 0.0150411 0.00840925 0.0191770 0.0182292 0.0525703 0.000890506
F390W 0.0147677 0.0159320 0.00887800 0.0198331 0.0192510 0.0601167 0.0/905
F438W 0.0163949 0.0140734 0.0108399 0.0187183 0.0171022 0.0811179 0.00107490
F555W 0.0283318 0.0269607 0.0182463 0.0347878 0.0337956 0.0979328 0.00137201
F775W 0.0213366 0.0189034 0.0132913 0.0252386 0.0237002 0.0670620 0.00326000
F814W 0.0157922 0.0134702 0.0108327 0.0177600 0.0161958 0.0879368 0.00129190
F850LP 0.0192433 0.0222559 0.0106786 0.0275235 0.0267428 0.0658254 0.00350738

F225W/F606W

F275W/F606W

F336W/F606W

F390W/F606W

F438W/F606W

F555W/F606W

F775W/F606W

F814W/F606W

F850LP/F606W

4: Summary

Shift

Rotation

Scale

Fit RMS

Number of Matched Stars