| IOC-MIPS_050a | 10630C | |||||||||
| Title: | MIPS Scattered Background Monitor -- Part 1 | |||||||||
| Objective: | Determine the level of scattered background light within MIPS when the scan mirror is | |||||||||
| moved to the "dark" position. By executing this measurement repeatedly as the telescope cools, | ||||||||||
| true dark current can be separated from background light scattered into the focal plane. Note that | ||||||||||
| a separate test for checking light scattered from point sources is required and will be executed under another program. | ||||||||||
| Description: | A series of repeated measurements of the signal seen in of the three MIPS | |||||||||
| including flow / state diagram | detector channels with the scan mirror positioned to place the detector in the dark. | |||||||||
| This is the first time the test will be executed. | ||||||||||
| Flow: | 1) Position scan mirror at 6.25 deg to place 24um array into the dark. | |||||||||
| 2) Take 10 3-sec exposures using the 24um channel. Use "raw" mode to return all readouts. | ||||||||||
| 3) Position scan mirror at 3.8 deg to put part of 70um array in dark (two positions required) | ||||||||||
| 4) Take 2x10 3-sec exposures using the 70um array. | ||||||||||
| 5) Position scan mirror at -4.5 deg to place 160um array into the dark. | ||||||||||
| 6) Take 10 3-second exposures using the 160um array. | ||||||||||
| Place in Schedule: | Can begin after aperture door is opened. | |||||||||
| (relative to water shed events) | ||||||||||
| Required Conditions: | Basic detector and scan mirror operation must be confirmed before | |||||||||
| executing this program. | ||||||||||
| This template should be executed at T~90K | ||||||||||
| Resources: | ||||||||||
| duration (best estimate) | 1hr | |||||||||
| real time downlink (Y / N) | No | |||||||||
| special post event actions (Y / N) | No | |||||||||
| Generates 40 DCEs. | ||||||||||
| Outcome: | ||||||||||
| description | The level of darkness within MIPS will be known and | |||||||||
| can be fed into the use of the Total Power Mode AOT. | ||||||||||
| can proceed in parallel with other activity | Yes provided other activites are not pointing the spacecraft at extremely bright sources | |||||||||
| must outcome be confirmed before next event / test /activity | No | |||||||||
| method of confirmation (sensor TLM, data analysis, etc.) | data analysis | |||||||||
| estimate of data turn around if required for confirmation | N/A | |||||||||
| Unique or included in planned AOT? | Should be the same as an IER for measuring dark current | |||||||||
| Contingency Plan: | ||||||||||
| "What if..." | This first execution of the scattered light test is likely to have all detectors | |||||||||
| saturated if the dark position only reduces the background by a factor of 10, | ||||||||||
| If dark is darker than this, then the 24um detectors might be responsive. | ||||||||||
| IOC Critical | Y | |||||||||
| References: | ||||||||||
| Template last updated: | 9/7/99 | |||||||||
| M. Rieke | ||||||||||