ECS Measurement SI Mode Trends

Statistics Run Date: 2021May17

Cold time is defined as any temperature reading <= -117.2 degrees C.

NOTE: Cold Temperature Limit value changed as of the April 12, 2021 run.

We are operating on 6 month epochs. The epochs start on the following Days of the Year:

DOY 032 and DOY 213.

The present epoch begins at: 2021:032:00:00:00.00 and today is: 2021:137:11:58:06.235 .

It is important to note that the target exposure times listed below will increase by a factor
of 12% every 6 month epoch due to the half-life of the calibration source.

Cold Time Statistics:

The Rules:

Rule #1: The key time period for balancing SI mode statistics is the 6 month Epoch
         By the end of the epoch, the SI mode statistics should match the rules stated below.

Rule #2: Each of the three, default, 6 chip, SI modes (or their 5 chip equivalents) must be used
         at least once in each load week.

           - If two SI modes are lagging in either cold time or total time, apportion the week's ECS
             measurements between the two of them roughly commensurate with the amount they are lagging.

           - The 6 month Epoch allows "even" correction of two lagging SI modes. No
             need to pile a weeks worth of ECS measurements on one SI mode if two are lagging.

Rule #3: Make certain to spread the amount of COLD ECS time as evenly as possible across all three SI modes
         Balance Cold measurement data between the three default 6-chip modes within 10%
         of each other on an Epoch basis


Rule #4: Spread the amount of *Total* ECS time as evenly as possible across all three SI modes. 

                 - Balance Total measurement data between the three default 6-chip modes within 10%
                   of each other on an Epoch basis.


         Rule #3 takes precedence over Rule #4.   


Rule #5:At least 60% of scheduled ECS measurement time must be -119.2 deg. C


Rule #6: Any ECS measurements during a Perigee Passage that are cold MUST be assigned to the nominal
         ECS run SI modes. i.e. Any requested Rawmode runs can be done with a warm focal plane.

Nominal SI Mode Mapping between 6,5 and 4 chip modes:

    6 chip     5 chip      4 chip
  TE_007AC -> TE_00C60 -> TE_00D78
  TE_00B26 -> TE_00C60 -> TE_00D78
  TE_007AE -> TE_00CA8 -> TE_00D78

All ECS SI mode possibilities are combined into 3 modes for the purposes of plotting.:

TE_007AC, TE_007AE and TE_00B26

When an SI mode can be combined to more than one of the main three, its total time will be added to the mode with the least total time.

TE_00C60 .

All of the TE_00CA8s get counted as TE_007AE

SI Mode to Chip Mappings: