Sequencer Site SIRTF IOC Activity c. 2002

CAID: MIPS-226 Title: Start-up Transients, 70um and 160um Arrays
 
System: MIPS Principal: dmkelly Deputy: alberto
Objective:   
To determine how soon after turn-on we can 
begin
to collect
high quality scientific data with the Ge arrays. 
The metrics are read noise, dark current,
responsivity, and stim repeatability.
 
Description: 
This task should be run immediately after the 
end
of the MIPS
start-up task.  It should follow the exact same
routines as
MIPS-160: 70 and 160 um Thermal Anneal 
Behavior. 
This consists of pointing the telescope at a
region of sky that is appropriate for dark
measurements and pointing the scan mirror 
to the
70um primary dark position (which also 
places the
160um array in the dark).  Data are then 
collected
by alternating between the read noise and 
dark
current IERs.
The test should run for about an hour.  
MIPS-160
should be run later during the same 
campaign. 
Comparing these two data sets will allow us 
to
discriminate between anneal-related and 
start-up
related transient effects.
 
Day:   65.0680555555591 Suggested Order:   K015
 
Must be preceded by these activities (list by CAID):   MIPS-246, MIPS-247, MIPS-248
 
Place in Schedule:   After dust-cover ejection.
 
Priority:   Necessary

Conditions

Maximum telescope temperature: 6.5 K
 
Minimum telescope temperature: 5.5 K
 
Should activity be repeated if focus changes?   No     Repeat if focus changes by 0 mm
 
Maximum absolute pointing uncertainty: 10 arcsec (1 sigma radial)
 
Maximum precision offset uncertainty: 10 arcsec  (1 sigma radial)
 
Observatory configuration: standard
 
Go/No Go criteria: CSMM, CE, and detectors must be operational.

Resources

Duration:   60 minutes
 
Real time downlink:   No   

Data Volume (uncompressed): 820 Mbits
 
List Blocks, AORs, SERs, IERs, or unique sequences required (uplink): Read noise and dark current IERs, probably modified slightly
 
List Analysis tools required (downlink):   standard pipeline IT software to determine read noise, dark current, and repeatability of stim amplitudes.

Outcome

Estimate of data turn around:   48 hours
 
Description: Read noise, dark current, and stim repeatability should be plotted versus time and compared with the results from the first hour of MIPS-160 to see if there are start-up transients.
 
Can proceed in parallel with other activity: No
 
Must outcome be confirmed before next activity: No
 
Method of Confirmation:   Comparison to the first hour of data from MIPS-160.
 
 
Success criteria: The test will be successful if the data are of sufficiently high quality to show trends in the stim repeatability.
 
Contingency plan:  If the detectors are unstable following the 30m start-up time, we have several options. The simplest and most costly would be to simply delay the start of science operations by a sufficient amount of time for the detectors to settle. A second approach would be to fill this time by doing 24um operations. The third approach would be to identify and implement a curing process that hastens the settling of the detectors. This might involve some amount of photon flooding, either with stim flashes or by looking at the sky.
 
 

Comments

 
References:  
 
Additional Comments:
 
This activity last updated: 9/15/2002 3:28:59 PM