| IOC-MIPS_070a | 10630C | ||||||||
| Title: | MIPS Scattered Background Monitor -- Part 5 | ||||||||
| 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 second 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 30-sec exposures using the 24um channel. | |||||||||
| 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. Should occur after Scattered Light Part 4. | |||||||||
| This template should be executed at T~12K | |||||||||
| 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 fifth execution of the scattered light test should have all detectors | ||||||||
| unsaturated even if the dark position only reduces the background by a factor of 10, | |||||||||
| If the some arrays are still saturated, analysis of MIPS optical paths will be needed. | |||||||||
| IOC Critical | Y | ||||||||
| References: | |||||||||
| Template last updated: | 9/7/99 | ||||||||
| M. Rieke | |||||||||