| IOC-MIPS_150a | 10560C,10700C | ||||||||
| Title: | Determination of MIPS Radiometric Throughput at 24um | ||||||||
| Objective: | Measure the fluxes of known celestial objects to calibrate the absolute throughput. | ||||||||
| Description: | |||||||||
| including flow / state diagram | |||||||||
| For each module and mode in MIPS, a celestial standard will be observed. | |||||||||
| At 24 microns a nominal sensitivity of 100:1 will be achieved. | |||||||||
| The observed fluxes will be compared to the modelled throughput of MIPS | |||||||||
| and will be used to update subsequent estimates of sensitivity and integration times required . | |||||||||
| I. Throughput in Scan Map mode | |||||||||
| Make scan maps at each scan rate (slow,medium,fast) | |||||||||
| Repeat the fast scan rate map to insure ~35sec integration. | |||||||||
| Use the scan map AOT. | |||||||||
| II. Throughput in Photometry Mode | |||||||||
| Place star on the 24um array . Take data in a 12 position | |||||||||
| dither pattern using 3,10, and 30 secs exposure at | |||||||||
| at each position. Repeat the entire pattern a total of 3 times. | |||||||||
| Use the photometry AOT. | |||||||||
| Required Conditions: | MIPS detector aliveness and electronics checks must have been performed. | ||||||||
| Pointing must support placing a star in the central 50% of the array. | |||||||||
| For 24um, background must be less than 4.0e-6 W/m^2/sr. | |||||||||
| or T<38K | |||||||||
| Resources: | duration (best estimate) | 1 hr | |||||||
| real time downlink (Y / N) | No | ||||||||
| special post event actions (Y / N) | No | ||||||||
| Generates ~234 DCEs depending on the amount of ovescan. | |||||||||
| Outcome: | |||||||||
| description | Revised throughput numbers | ||||||||
| can proceed in parallel with other activity | No, dedicated observing. | ||||||||
| must outcome be confirmed before next event / test /activity | Outcome must be confirmed before tests of ultimate sensitivity can | ||||||||
| be executed. | |||||||||
| method of confirmation (sensor TLM, data analysis, etc.) | Data analysis | ||||||||
| estimate of data turn around if required for confirmation | 48 hrs | ||||||||
| Unique or included in planned AOT? | |||||||||
| Planned AOTs but with non-standard pipeline processing as calibration data | |||||||||
| will not yet be available | |||||||||
| Contingency Plan: | |||||||||
| "What if..." | If throughput is radically different than pre-launch estimates, further analysis and | ||||||||
| tests to pin point the nature of the problem will be required (eg., are other instruments | |||||||||
| affected similarly, are backgrounds as expected and so on). | |||||||||
| IOC Critical | Y | ||||||||
| References: | |||||||||
| Template last updated: | 7-Sep-99 | ||||||||
| M. Rieke | |||||||||