| IOC-MIPS_250a | 10240C,10230C | ||||||||
| Title: | Cosmic-ray limits on integration times | ||||||||
| Objective: | To determine the maximum useful MIPS integration times in the | ||||||||
| presence of cosmic-ray hits. | |||||||||
| Description: | While illuminating the detectors at a low level with the stimulators, take images | ||||||||
| at many different integration times up to the maximum allowed value to | |||||||||
| evaluate the trade off between "background limited" and "not completely | Related: | Low-background data taken at | |||||||
| swamped with particle hits." | different integration times to exercise the system. | ||||||||
| For example, this could be accomplished by executing a series of photometry | |||||||||
| AOTs over a range of integration times from 3 to 60 seconds. | |||||||||
| E.g., 3, 10, 30, and 60 seconds. | |||||||||
| Place in Schedule: | For 24um, the backgrd radiance must be less than 1.0E-11 W/cm2/sr (< 30K). | ||||||||
| For 70um, the backgrd radiance must be less than 1.0E-12 W/cm2/sr (< 12 K). | |||||||||
| For 160um, the backgrd radiance must be less than 5.4E-13 W/cm2/sr (< 6 K). | |||||||||
| It may be possible to split this test into parts executed at different times based | |||||||||
| on telescope temperature. | |||||||||
| Location of MIPS apertures must be completed. | |||||||||
| Basic instrument commanding and functionality must have been confirmed. | |||||||||
| Required Conditions: | CTA temperature must be low enough that stray light is much lower | ||||||||
| (20 %) than the background sky level in each band. | |||||||||
| Boresite pointed to batch of sky without bright sources. | |||||||||
| Pointing accuracy is not at all critical (better than a few arcminutes is fine), | |||||||||
| but sources shouldn't be drifting across the array and so stability should be | |||||||||
| better than 1" (about 1/2 a 24um pixel) over 60 seconds. | |||||||||
| Resources: | |||||||||
| duration (best estimate) | 22 minutes | ||||||||
| real time downlink (Y / N) | No | ||||||||
| special post event actions (Y / N) | Special data analysis | ||||||||
| Outcome: | |||||||||
| description | SUR data for each MIPS array | ||||||||
| can proceed in parallel with other activity | Yes | ||||||||
| 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 | 48 hrs | ||||||||
| number of DCEs generated | 144 | ||||||||
| Unique or included in planned uplink or downlink/analysis tool | Can use photometry AOT | ||||||||
| Special data analysis | |||||||||
| Contingency Plan: | Acquire required data through normal operations. | ||||||||
| "What if..." | This is a test of conditions external to SIRTF and | ||||||||
| cannot fail. | |||||||||
| IOC Critical | N | ||||||||
| References: | |||||||||
| Template last updated: | 12-Sep-99 | ||||||||
| C.W. Engelbracht | |||||||||