MIPS_255a Radiometry Tests


IOC-MIPS_255a     10520C,10600C,10700C            
Title:   MIPS Radiometry tests: Sensitivity and Stability, both point sources and extended sources              
                   
Objective:   Determine the sensitivity to both point and extended sources and check the stability over a week time scale.              
                   
Description:                
including flow / state diagram     For each module two different celestial standards will be observed, one a calibrator star and            
      the other a moderately high surface brightness extended source (will choose objects from IRAS or ISO programs).            
      At 24 and 70 microns a nominal sensitivity of 100:1 will be achieved will at            
      160um at least 10:1 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 .            
      After this test has executed once, it must be repeated again approximately one day and one week later            
      See attached page for listing of events            
Place in Schedule:                
(relative to water shed events)     CTA and instrument must be at 5.5K.            
                   
Required Conditions:   Basic instrument functionality must be confirmed.            
      MIPS throughput test must already be done.            
                   
Resources:                  
  duration (best estimate)     12 hrs (split into 6 2-hr sessions, 2 hr on pt. source, 2 hrs on extended,        
          repeat pattern for a total of three executions)        
  real time downlink (Y / N)     No          
  special post event actions (Y / N)     No          
                   
Outcome:                  
  description       Final sensitivities will be available after the read noise test performed      
            limited stability information will be available.      
  can proceed in parallel with other activity       No, dedicated observing      
  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?                  
      Uses standard AOTs but with non-standard pipeline processing as calibration data will be derived from this test.            
                   
Contingency Plan:                  
"What if..."     If test fails for any reason or if repeatability is worse than ~10%, test must be repeated to understand why.            
                   
IOC Critical     Y            
                   
References:                  
                   
Template last updated:     27-Jul-98 M. Rieke          
                   
  Events: (Same as list for Throughput test, note that this sequence must be repeated for both the              
    point source and the extended source and the entire pattern will be done three times a day and a week apart).              
                   
    I. Throughput in Scan Map mode              
                   
    Make scan maps at each scan rate (slow,medium,fast) such that the star            
      traverses each array. Repeat as needed to get 50 secs of exposure on the star.            
      Use the scan map AOT.            
                   
    II. Throughput in Photometry mode              
                   
      Place star on each array (24um,70um,160um) in turn. Take data in a 2x2            
      dither pattern on each array with 50secs (or nearest larger number given allowed            
      exposure times) at each position. For 24um, repeat test using 3,10,and 30 secs            
      as the basic exposure. For 70 and 160um, repeat test using the 3 and 10 sec            
      exposures.            
      Use the photometry/superreolution AOT.            
                   
    III. Throughput in Superresolution Mode              
                   
      Switch 70um module to fine plate scale. Take data in a 2x2 dither pattern            
      with an expsure time of 200 secs. Repeat using each of the base integration            
      times of 3 and 10 sec.            
      Use the photometry/superresolution AOT.            
                   
    IV. Throughput in SED Mode              
                   
      Place star near one end of the SED slit. Take a series of exposures totalling            
      150 secs at each of five positions along the slit. Repeat for each of the basic            
      integration times (3 and 10 secs).            
                   
                   


Last Updated on 10/7/99
By Marcia Rieke
Email: mrieke@as.arizona.edu