| CAID: MIPS-080 | Title: 70um Dark Position Test | |
| System: MIPS | Principal: dmkelly | Deputy: cengelbracht |
| Objective: | Determine the optimum scan mirror positions for collecting 70um darks. |
| Description: | While pointing at a region of very bright sky, collect a set of 10 3s DCEs, with stim flashes on the second and last DCEs. Then point to the 70um primary dark position, set relpos to 1568, and take a set of 10 10s DCEs with stim flashes on the second and last DCEs. Increment relpos by 160 counts and repeat this set of 10 DCEs. Repeat another 5 times, up to a final relpos value of 2528. Repeat at the 70um secondary dark position. |
| Day: 61.2895833333387 | Suggested Order: O100 | ||
| Must be preceded by these activities (list by CAID): MIPS-322 | |||
| Place in Schedule: This test can be made at any time after the 70um first light test. Since we will be making dark measurements throughout IOC, it would be nice to get this test in early so that we can determine the best 70um dark positions early in IOC. | |||
| Priority: Necessary | |||
Conditions | |||
| Maximum telescope temperature: | 12 K | ||
| Minimum telescope temperature: | 5.5 K | ||
| Should activity be repeated if focus changes? | No Repeat if focus changes by 0 mm | ||
| Maximum absolute pointing uncertainty: | 3600 arcsec (1 sigma radial) | ||
| Maximum precision offset uncertainty: | 3600 arcsec (1 sigma radial) | ||
| Observatory configuration: | standard | ||
| Go/No Go criteria: | The telescope must be cool enough to provide a reasonably low 70um background | ||
Duration: 40 minutes
| | Real time downlink:
No | | |||
| Data Volume (uncompressed): 275 Mbits | |||
| List Blocks, AORs, SERs, IERs, or unique sequences required (uplink): Special IER | |||
| List Analysis tools required (downlink): Standard pipeline, modified to use stims to calibrate the background | |||
| Estimate of data turn around: 24 hours | |||
| Description: Determine the stim-calibrated background level for the relevant half of the array for each of the relpos positions, and plot background level vs scan mirror angle. Determine which scan mirror gives the darkest background. Make sure that all pixels are in the dark in at least one of the two dark positions. | |||
| Can proceed in parallel with other activity: No | |||
| Must outcome be confirmed before next activity: No | |||
| Method of Confirmation: None | |||
| Success criteria: External light levels are bright enough that an assessment can be made of which scan mirror position provides the lowest light levels | |||
| Contingency plan: If improved scan mirror positions cannot be found in orbit, we will have to use the positions that were determined in ground testing. | |||
Comments | |||
| References: | |||
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Additional Comments:
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| This activity last updated: 7/2/2002 4:02:10 PM | |||