7.2 Specifying an IR Observation
In the HST proposal system, the parameters for an IR observation available to General Observers are:
- Configuration: always WFC3/IR.
- Mode: always MULTIACCUM.
- Aperture: must be specified. See Sections 7.4.4 and 7.4.5 for the dimensions, location, and reference point (target placement) of the full array and subarray apertures.
- Spectral Element: must be specified for each exposure; see Section 7.5.
- Optional Parameters: in the IR channel, SAMPSEQ specifies a predefined sequence of times at which the detector is read out, and NSAMP specifies the total number of readouts (and thus the total exposure time); see Section 7.7. SAMPSEQ and NSAMP are required for IR observations.
- Special Requirements: see the Phase II Proposal Instructions for details of Special Requirements related to the timing of visits and for dithering and mosaicking. Also available is the exposure-level Special Requirement POS TARG for offsetting the target from the default reference point of the aperture (see Section 7.4.3 for a discussion of the IR channel coordinate system) and Appendix C for the POS TARGs associated with the WFC3/IR patterns.
- Number of Iterations and Time per Exposure: in cases where two or more identical exposures are desired, the Number of Iterations may be set to 2 or more. In the IR channel, the Time per Exposure is fixed by the combination of SAMPSEQ and NSAMP (see item 5 above) and thus is not specified separately. Through various combinations of SAMPSEQ and NSAMP, it is possible to achieve exposure times ranging from 2.93 to 2756 s for readouts of the full detector array (Table 7.8); considerably shorter exposures are possible using subarrays (Table 7.9).
-
WFC3 Instrument Handbook
- • Acknowledgments
- Chapter 1: Introduction to WFC3
- Chapter 2: WFC3 Instrument Description
- Chapter 3: Choosing the Optimum HST Instrument
- Chapter 4: Designing a Phase I WFC3 Proposal
- Chapter 5: WFC3 Detector Characteristics and Performance
-
Chapter 6: UVIS Imaging with WFC3
- • 6.1 WFC3 UVIS Imaging
- • 6.2 Specifying a UVIS Observation
- • 6.3 UVIS Channel Characteristics
- • 6.4 UVIS Field Geometry
- • 6.5 UVIS Spectral Elements
- • 6.6 UVIS Optical Performance
- • 6.7 UVIS Exposure and Readout
- • 6.8 UVIS Sensitivity
- • 6.9 Charge Transfer Efficiency
- • 6.10 Other Considerations for UVIS Imaging
- • 6.11 UVIS Observing Strategies
- Chapter 7: IR Imaging with WFC3
- Chapter 8: Slitless Spectroscopy with WFC3
-
Chapter 9: WFC3 Exposure-Time Calculation
- • 9.1 Overview
- • 9.2 The WFC3 Exposure Time Calculator - ETC
- • 9.3 Calculating Sensitivities from Tabulated Data
- • 9.4 Count Rates: Imaging
- • 9.5 Count Rates: Slitless Spectroscopy
- • 9.6 Estimating Exposure Times
- • 9.7 Sky Background
- • 9.8 Interstellar Extinction
- • 9.9 Exposure-Time Calculation Examples
- Chapter 10: Overheads and Orbit Time Determinations
-
Appendix A: WFC3 Filter Throughputs
- • A.1 Introduction
-
A.2 Throughputs and Signal-to-Noise Ratio Data
- • UVIS F200LP
- • UVIS F218W
- • UVIS F225W
- • UVIS F275W
- • UVIS F280N
- • UVIS F300X
- • UVIS F336W
- • UVIS F343N
- • UVIS F350LP
- • UVIS F373N
- • UVIS F390M
- • UVIS F390W
- • UVIS F395N
- • UVIS F410M
- • UVIS F438W
- • UVIS F467M
- • UVIS F469N
- • UVIS F475W
- • UVIS F475X
- • UVIS F487N
- • UVIS F502N
- • UVIS F547M
- • UVIS F555W
- • UVIS F600LP
- • UVIS F606W
- • UVIS F621M
- • UVIS F625W
- • UVIS F631N
- • UVIS F645N
- • UVIS F656N
- • UVIS F657N
- • UVIS F658N
- • UVIS F665N
- • UVIS F673N
- • UVIS F680N
- • UVIS F689M
- • UVIS F763M
- • UVIS F775W
- • UVIS F814W
- • UVIS F845M
- • UVIS F850LP
- • UVIS F953N
- • UVIS FQ232N
- • UVIS FQ243N
- • UVIS FQ378N
- • UVIS FQ387N
- • UVIS FQ422M
- • UVIS FQ436N
- • UVIS FQ437N
- • UVIS FQ492N
- • UVIS FQ508N
- • UVIS FQ575N
- • UVIS FQ619N
- • UVIS FQ634N
- • UVIS FQ672N
- • UVIS FQ674N
- • UVIS FQ727N
- • UVIS FQ750N
- • UVIS FQ889N
- • UVIS FQ906N
- • UVIS FQ924N
- • UVIS FQ937N
- • IR F098M
- • IR F105W
- • IR F110W
- • IR F125W
- • IR F126N
- • IR F127M
- • IR F128N
- • IR F130N
- • IR F132N
- • IR F139M
- • IR F140W
- • IR F153M
- • IR F160W
- • IR F164N
- • IR F167N
- Appendix B: Geometric Distortion
- Appendix C: Dithering and Mosaicking
- Appendix D: Bright-Object Constraints and Image Persistence
-
Appendix E: Reduction and Calibration of WFC3 Data
- • E.1 Overview
- • E.2 The STScI Reduction and Calibration Pipeline
- • E.3 The SMOV Calibration Plan
- • E.4 The Cycle 17 Calibration Plan
- • E.5 The Cycle 18 Calibration Plan
- • E.6 The Cycle 19 Calibration Plan
- • E.7 The Cycle 20 Calibration Plan
- • E.8 The Cycle 21 Calibration Plan
- • E.9 The Cycle 22 Calibration Plan
- • E.10 The Cycle 23 Calibration Plan
- • E.11 The Cycle 24 Calibration Plan
- • E.12 The Cycle 25 Calibration Plan
- • E.13 The Cycle 26 Calibration Plan
- • E.14 The Cycle 27 Calibration Plan
- • E.15 The Cycle 28 Calibration Plan
- • E.16 The Cycle 29 Calibration Plan
- • E.17 The Cycle 30 Calibration Plan
- • E.18 The Cycle 31 Calibration Plan
- • Glossary