| CAID: MIPS-351 | Title: Flux Calibration 2 | |
| System: MIPS | Principal: dhines | Deputy: cengelbracht, dfrayer, SStolovy |
| Objective: | Measure the instrumental response from observations of stars of known flux density to derive transformation from instrumental to physical units (Jy/sq arcsec). This is the second pass which will check stability and repeatability of the calibration. |
| Description: | n each waveband, 3 flux standards will be observed in (small field) photometry mode. In addition, a short observation of the 24um stimulator (5 DCEs beforeand after one of the 24um standards) will be made to calibrate that stimulator and check for STIM stability. At 24um, each star can be observed with 2 cycles of 3s DCEs. At 70um and 160um, 2 cycles of 10s DCEs will be required. The standards are listed in the MIPS SDD. |
| Day: 61.3451388888934 | Suggested Order: O200 | ||
| Must be preceded by these activities (list by CAID): MIPS-350 | |||
| Place in Schedule: | |||
| Priority: Necessary | |||
Conditions | |||
| Maximum telescope temperature: | 6.5 K | ||
| Minimum telescope temperature: | 5.5 K | ||
| Should activity be repeated if focus changes? | Yes Repeat if focus changes by 0 mm | ||
| Maximum absolute pointing uncertainty: | 5 arcsec (1 sigma radial) | ||
| Maximum precision offset uncertainty: | 0.4 arcsec (1 sigma radial) | ||
| Observatory configuration: | |||
| Go/No Go criteria: | |||
Duration: 83 minutes
| | Real time downlink:
No | | |||
| Data Volume (uncompressed): 40.5 Mbits | |||
| List Blocks, AORs, SERs, IERs, or unique sequences required (uplink): photometry AOT and 24um stim IER | |||
| List Analysis tools required (downlink): Standard pipelined data. S-IDP3 will be used to extract the photometry. Comparisons with standard Kurucz models pinned to 2MASS will be integrated over the appropriate MIPS bandpass to estimate the expected flux density. The conversion from DN/s to Jy/sec (per pixel or arcsec) will then be derived. | |||
| Estimate of data turn around: 24 hours | |||
| Description: The conversion factor between instrument units and physical units will be derived. The uncertainties must be dominated by the repeatability (4-5%), not by photon statistics.per se. | |||
| Can proceed in parallel with other activity: No | |||
| Must outcome be confirmed before next activity: No | |||
| Method of Confirmation: Three stars will be used. The conversion should be consistent (within the 4% repeatability). The stars should match predictions for a stellar atmosphere. A descrepency between bands may hail the detection of a debirs disk, or information that there is a problem with the system. | |||
| Success criteria: Sufficiently high S/N (100:1) must be obtained. Flat field and dark frames must be mature. There should be a consistent flux calibration from all 3 stars in each band. The solution should follow | |||
| Contingency plan: If the stars do not provide flux density conversions that are consistent with each other and across the three MIPS bands, then the taks must be repeated. If one of the stars appears to have a debris disk, the task must be repeated with a new star. If all three stars are inconsistent, then the task must be repeated AFTER corrective action is taken based on analysis of the Instrument. | |||
Comments | |||
| References: MIPS SDD | |||
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Additional Comments:
Required Conditions: MIPS detector aliveness tests must have been performed. Must be able to place a star in the width of a scan (5'). Backgrounds must be less than the equivalent of 200,000 photons/sec at 160um: 160um <= 1.10E-07 W/m^2/sr or T<7.4K One forward/back scan generates 344 DCEs between the two arrays. A total of 1720 DCEs are generated in the complete test. | |||
| This activity last updated: 6/8/2002 5:34:16 PM | |||