17.10 SM4 and SMOV4 Calibration
After the successful repair of STIS during Servicing Mission 4 (SM4), a plan for verification and preliminary calibration was executed during the subsequent period of Servicing Mission Observatory Verification (SMOV4). The SMOV4 plan for STIS focused on ensuring that observers can obtain data of sufficient quality to meet their scientific goals, but some of the more time consuming calibration observations that do not affect the planning of observations and which can be applied retroactively, (e.g., high signal-to-noise pixel-to-pixel flats and high precision sensitivity determinations for all central wavelength settings), were deferred and included in the Cycle 17 calibration plan. As a result the initial calibration precision for STIS data products delivered early in Cycle 17 is less than that which will ultimately be obtainable when the final calibration reference files become available for those observations. Significant updates to the calibration will be announced on the STIS webpages.
A summary of preliminary STIS SMOV4 activities follows.
STIS-01: Modes and Data Interface Checks
- Includes turn-on and telemetry checks that verify the capability to enter required instrument and detector states during normal operations.
- Includes the initial turn-on of the MAMA low voltage (LV) and checks of the MAMA readout electronics that can be made with the high voltage (HV) off.
- Includes the initial turn-on of the CCD thermal electric cooler (TEC).
STIS-02: Memory Load and Dump
- Loads, dumps and compares sections of memory with stored images to verify operations.
STIS-03: Science Data Buffer Check with Self-Test
- Loads a test pattern into the science data buffer. The buffer contents are subsequently examined using memory and exposure dumps.
STIS-04: Mechanism Mini-Functional
- Initializes all mechanisms, except the focus and corrector mechanism, commands them to selected positions, and moves them over the full range necessary for normal operations. Commanded motions are verified using telemetry.
STIS-05: CCD Anneal
- The CCD is warmed from ~ -80C to ~ +5C to repair hot pixels. A series of darks and biases are taken to monitor and evaluate CCD performance before and after the anneal process.
STIS-06: CCD Functional
- Bias, dark, and tungsten lamp exposures are taken, using various gains and binning, to measure the baseline CCD performance.
STIS-07: CCD Bias and Dark Monitor
- Acquisition of sufficient dark and bias frames to permit construction of superbias and superdark frames needed for pipeline image reduction.
STIS-08: Aperture Wheel and Lamp Functional Tests
- Aperture positions are checked using tungsten lamp images through several slits.
- Thermal drifts are measured using repeated observations of the
0.2X0.2aperture interspersed throughout the test.
- Pt/Cr-Ne lamp functionality is checked by obtaining images with the
STIS-09: STIS to FGS Alignment
- Target positioning accuracy in the STIS aperture plane using fine guidance sensors (FGS) guiding is measured using star field and lamp images illuminating the
STIS-10: CCD Optical Format Verification
- Measurement of the location of the CCD spectra and images on the detector for each CCD spectral element (
STIS-11: External Focus Check
- Evaluation of the STIS PSF at the aperture plane using small slit (
ACQ/PEAKimages and point source images with the
- Determination of the shape of the PSF at ultraviolet (UV) wavelengths from spectra acquired using the
- Estimation of the STIS focus through comparison of the aperture throughputs and PSF shape with previous values.
STIS-12: Corrector and Focus Alignment
- Coarse and/or fine adjustments of the STIS focus are made if STIS-11 finds a significantly degraded PSF. If a focus adjustment is necessary, then the STIS CM1 mirror will be adjusted in tip/tilt and focus to optimize the PSF. Coarse adjustments optimize the encircled energy of an isolated star observed through the
50CCDaperture while fine adjustment sweeps optimize the small aperture throughputs.
STIS-13: CCD Spectroscopic Image Quality and ACQ Tests
- Checks the cross dispersion PSF using point source spectra obtained at multiple positions along a long slit.
- Peak-ups are executed to check target centering at the E1 slit location.
STIS-14: CCD CTE Check
- Lamp exposures are taken at multiple positions along the
0.05X31NDslit, and read-out using amplifiers D and B, to search for, and compare, CTE losses as a function of Y-position on the detector.
STIS-15: CCD Spectroscopic Throughputs
- Determination of the throughput of each spectroscopic CCD mode from observations of the standard high-latitude sdO-type star AGK+81D266.
STIS-16: CCD Image and Pointing Stability
- The pointing stability is assessed after execution of a large pointing maneuver selected to apply a significant thermal change to STIS. Star field images and lamp images of an aperture are interspersed to measure the image stability at detector and aperture planes.
FUV-MAMA HV Recovery
FUV-MAMAvoltage is ramped-up in stages while taking dark exposures and using on-board count rate monitors to protect against anomalies. Fold analysis is performed after it has been verified that the voltage can be safely ramped-up to the required level.
NUV-MAMA HV Recovery
NUV-MAMAvoltage is ramped-up in stages while taking dark exposures and using on-board count rate monitors to protect against anomalies. A fold analysis is performed after it has been verified that the voltage can be safely ramped-up to the required level.
FUV-MAMA Dark Measure
- Characterization of the
FUV-MAMAglow as a function of detector warm-up through the acquisition of a series of darks spanning the 5-orbit SAA-free period.
STIS-20: NUV Dark Monitor
- Monitoring of the NUV phosphorescent window glow to determine the equilibrium behavior and the onset of science observations.
FUV-MAMA Optical Format Verification
- Measurement of the location of the FUV spectra on the detector for each
FUV-MAMAspectral element (
E140H) using the
NUV-MAMA Optical Format Verification
- Measurement of the location of the NUV spectra on the detector for each
NUV-MAMAspectral element (
PRISM) using the
FUV-MAMA Image Quality
- Checks the cross dispersion PSF using point source spectra of
G140Lobtained at multiple positions along a long slit.
NUV-MAMA Image Quality
- Checks the cross dispersion PSF using point source spectra of
G230L obtained at multiple positions along a long slit.
STIS-25: MAMA Spectroscopic Throughputs
- Determination of the throughput of each spectroscopic MAMA mode, except the NUV PRISM, from standard star observations (preferably GRW+70D5824, AGK+81D266, or BD+28D4211).
STIS-26: MAMA Image Stability
- The pointing stability is assessed after the execution of a large pointing maneuver selected to apply a significant thermal change to STIS. Repeated lamp images of an aperture are obtained to measure the image stability at detector over a two orbit period.
STIS Instrument Handbook
- • Acknowledgments
- Chapter 1: Introduction
Chapter 2: Special Considerations for Cycle 31
- • 2.1 STIS Repair and Return to Operations
- • 2.2 Summary of STIS Performance Changes Since 2004
- • 2.3 New Capabilities for Cycle 31
- • 2.4 Use of Available-but-Unsupported Capabilities
- • 2.5 Choosing Between COS and STIS
- • 2.6 Scheduling Efficiency and Visit Orbit Limits
- • 2.7 MAMA Scheduling Policies
- • 2.8 Prime and Parallel Observing: MAMA Bright-Object Constraints
- • 2.9 STIS Snapshot Program Policies
- Chapter 3: STIS Capabilities, Design, Operations, and Observations
- Chapter 4: Spectroscopy
- Chapter 5: Imaging
- Chapter 6: Exposure Time Calculations
- Chapter 7: Feasibility and Detector Performance
Chapter 8: Target Acquisition
- • 8.1 Introduction
- • 8.2 STIS Onboard CCD Target Acquisitions - ACQ
- • 8.3 Onboard Target Acquisition Peakups - ACQ PEAK
- • 8.4 Determining Coordinates in the International Celestial Reference System (ICRS) Reference Frame
- • 8.5 Acquisition Examples
- • 8.6 STIS Post-Observation Target Acquisition Analysis
- Chapter 9: Overheads and Orbit-Time Determination
- Chapter 10: Summary and Checklist
- Chapter 11: Data Taking
Chapter 12: Special Uses of STIS
- • 12.1 Slitless First-Order Spectroscopy
- • 12.2 Long-Slit Echelle Spectroscopy
- • 12.3 Time-Resolved Observations
- • 12.4 Observing Too-Bright Objects with STIS
- • 12.5 High Signal-to-Noise Ratio Observations
- • 12.6 Improving the Sampling of the Line Spread Function
- • 12.7 Considerations for Observing Planetary Targets
- • 12.8 Special Considerations for Extended Targets
- • 12.9 Parallel Observing with STIS
- • 12.10 Coronagraphic Spectroscopy
- • 12.11 Coronagraphic Imaging - 50CORON
- • 12.12 Spatial Scans with the STIS CCD
Chapter 13: Spectroscopic Reference Material
- • 13.1 Introduction
- • 13.2 Using the Information in this Chapter
- • First-Order Grating G750L
- • First-Order Grating G750M
- • First-Order Grating G430L
- • First-Order Grating G430M
- • First-Order Grating G230LB
- • Comparison of G230LB and G230L
- • First-Order Grating G230MB
- • Comparison of G230MB and G230M
- • First-Order Grating G230L
- • First-Order Grating G230M
- • First-Order Grating G140L
- • First-Order Grating G140M
- • Echelle Grating E230M
- • Echelle Grating E230H
- • Echelle Grating E140M
- • Echelle Grating E140H
- • PRISM
- • PRISM Wavelength Relationship
- • 52X0.05 Aperture
- • 52X0.05E1 and 52X0.05D1 Pseudo-Apertures
- • 52X0.1 Aperture
- • 52X0.1E1 and 52X0.1D1 Pseudo-Apertures
- • 52X0.2 Aperture
- • 52X0.2E1, 52X0.2E2, and 52X0.2D1 Pseudo-Apertures
- • 52X0.5 Aperture
- • 52X0.5E1, 52X0.5E2, and 52X0.5D1 Pseudo-Apertures
- • 52X2 Aperture
- • 52X2E1, 52X2E2, and 52X2D1 Pseudo-Apertures
- • 52X0.2F1 Aperture
- • 0.2X0.06 Aperture
- • 0.2X0.2 Aperture
- • 0.2X0.09 Aperture
- • 6X0.2 Aperture
- • 0.1X0.03 Aperture
- • FP-SPLIT Slits 0.2X0.06FP(A-E) Apertures
- • FP-SPLIT Slits 0.2X0.2FP(A-E) Apertures
- • 31X0.05ND(A-C) Apertures
- • 0.2X0.05ND Aperture
- • 0.3X0.05ND Aperture
- • F25NDQ Aperture
- 13.5 Spatial Profiles
- 13.6 Line Spread Functions
- • 13.7 Spectral Purity, Order Confusion, and Peculiarities
- • 13.8 MAMA Spectroscopic Bright Object Limits
Chapter 14: Imaging Reference Material
- • 14.1 Introduction
- • 14.2 Using the Information in this Chapter
- 14.3 CCD
- 14.4 NUV-MAMA
- • 25MAMA - FUV-MAMA, Clear
- • 25MAMAD1 - FUV-MAMA Pseudo-Aperture
- • F25ND3 - FUV-MAMA
- • F25ND5 - FUV-MAMA
- • F25NDQ - FUV-MAMA
- • F25QTZ - FUV-MAMA, Longpass
- • F25QTZD1 - FUV-MAMA, Longpass Pseudo-Aperture
- • F25SRF2 - FUV-MAMA, Longpass
- • F25SRF2D1 - FUV-MAMA, Longpass Pseudo-Aperture
- • F25LYA - FUV-MAMA, Lyman-alpha
- • 14.6 Image Mode Geometric Distortion
- • 14.7 Spatial Dependence of the STIS PSF
- • 14.8 MAMA Imaging Bright Object Limits
- Chapter 15: Overview of Pipeline Calibration
- Chapter 16: Accuracies
Chapter 17: Calibration Status and Plans
- • 17.1 Introduction
- • 17.2 Ground Testing and Calibration
- • 17.3 STIS Installation and Verification (SMOV2)
- • 17.4 Cycle 7 Calibration
- • 17.5 Cycle 8 Calibration
- • 17.6 Cycle 9 Calibration
- • 17.7 Cycle 10 Calibration
- • 17.8 Cycle 11 Calibration
- • 17.9 Cycle 12 Calibration
- • 17.10 SM4 and SMOV4 Calibration
- • 17.11 Cycle 17 Calibration Plan
- • 17.12 Cycle 18 Calibration Plan
- • 17.13 Cycle 19 Calibration Plan
- • 17.14 Cycle 20 Calibration Plan
- • 17.15 Cycle 21 Calibration Plan
- • 17.16 Cycle 22 Calibration Plan
- • 17.17 Cycle 23 Calibration Plan
- • 17.18 Cycle 24 Calibration Plan
- • 17.19 Cycle 25 Calibration Plan
- • 17.20 Cycle 26 Calibration Plan
- • 17.21 Cycle 27 Calibration Plan
- • 17.22 Cycle 28 Calibration Plan
- • 17.23 Cycle 29 Calibration Plan
- • 17.24 Cycle 30 Calibration Plan
- Appendix A: Available-But-Unsupported Spectroscopic Capabilities
- • Glossary