E.15 The Cycle 29 Calibration Plan

The Cycle 29 calibration plan is being executed from November 2021 through October 2022. The individual programs are listed in Table E.15 and are described in more detail on the WFC3 Calibration Plan webpage. Following the link to Cycle 29 Calibration, a similar table may be found with direct links to the phase II programs and observation dates. This information may alternately be accessed via the HST Program Information webpage by entering the Proposal ID.

The WFC3 Cycle 29 webpage also links to a PDF presentation summarizing WFC3 usage in the latest cycle and comparing the current plan with the prior cycle. This document contains more details on the calibration justification and in many cases includes supporting figures with the latest results from regular monitoring.

The Cycle 29 calibration plan was designed to:

  • Maintain and update the standard reference files (biases, darks, linearity, CTE traps, UVIS anomalous QE pixels, post-flash)
  • Monitor the health of the instrument (throughput, gain, hysteresis, bad/hot pixels, sink pixels, CTE decline, stability of the post-flash LED, filter transmission, state of the CSM, number of IR blobs, wavelength and flux stability of the grisms)
  • Support new initiatives and obtain supplemental (non-routine) calibration data

Four new calibration programs will supplement the standard monitoring. These programs (16861, 16862, 16863, 16864) were designed to:

  • Test for changes in the IR filter sensitivity with wavelength by leveraging off of prior observations of stellar clusters
  • Explore a new method for measuring CTE losses based on long darks with flash levels the 20-50 electron background range

  • Measure the impact of CTE losses on extended sources by comparing with early inflight observations
  • Improve table-based CTE corrections for photometry and astrometry for backgrounds between 5 and 30 electrons

The results of these calibration programs will be documented in Instrument Science Reports on the WFC3 website at:

Table E.16: The Cycle 29 Calibration Programs

16564WFC3 UVIS Anneal
16565WFC3 UVIS Bowtie Monitor
16566WFC3 UVIS CCD Daily Monitor Part 1
16567WFC3 UVIS CCD Daily Monitor Part 2
16568WFC3 UVIS CCD Daily Monitor Part 3
16569WFC3 UVIS CCD Unflashed (CTE) Monitor
16570WFC3 UVIS Post-flash Monitor
16571WFC3 UVIS CCD Gain Stability
16572WFC3 UVIS CTI Monitor (EPER)
16573WFC3 UVIS CTE Monitor (star cluster)
16574WFC3 Characterization of UVIS traps with Charge Injection
16575WFC3 IR Dark Monitor
16576WFC3 IR Linearity Monitor
16577WFC3 IR Gain Monitor
16578WFC3 UVIS Shutter Monitoring
16579WFC3 UVIS and IR Photometry
16580WFC3 Time Dependent Sensitivity
16581WFC3 UVIS Grism Wavelength Calibration
16582WFC3 IR Wavelength Calibration
16583WFC3 IR Flux/Trace Monitor
16584WFC3 UVIS Pixel-to-Pixel QE Variations via Internal Flats
16585WFC3 UVIS Internal Flats
16586WFC3 IR Internal Flats
16587WFC3 CSM Monitor with Earth Flats
16588WFC3 Astrometric Scale Monitoring

Testing a New Method for Pinning Down CTE Losses


Supplemental Empirical CTE Calibrations for Photometry and Astrometry


CTE Evaluation of Resolved Objects


WFC3/IR Time-Dependent Sensitivity in Staring Mode (Clusters)