Cold time is defined as any temperature reading <= -119.2 degrees C.
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: 2021:060:19:22:26.695 .
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.
II. Statistics Since the Start of the Current Epoch
Cold Time Statistics:
| Chip | Required (seconds) | Achieved (seconds) |
|---|---|---|
| I0 | 160000 | 1280.2 |
| I1 | 160000 | 9429.0 |
| I2 | 160000 | 9429.0 |
| I3 | 160000 | 9429.0 |
| S0 | 80000 | 7983.2 |
| S1 | 100000 | 7983.2 |
| S2 | 160000 | 9263.4 |
| S3 | 200000 | 17412.2 |
| S4 | 80000 | 7983.2 |
| S5 | 80000 | 7983.2 |
| Recovered Science Time (seconds): | 9486.0 |
|---|
| SI Mode | Total Number of Obs. | Total Exposure Time (sec) | Average Exposure (sec/obs) | Primary 6 Chip SI Modes | TE_007AC | 6 | 31191.00 | 5198.50 |
|---|---|---|---|
| TE_007AE | 6 | 41508.20 | 6918.03 |
| TE_00B26 | 6 | 31333.00 | 5222.17 | Old 6 Chip SI Modes | TE_00216 | 0 | 0.00 | 0.00 |
| TE_0021C | 0 | 0.00 | 0.00 |
| TE_008EA | 0 | 0.00 | 0.00 | 5 Chip SI Modes | TE_00C60 | 1 | 9717.00 | 9717.00 |
| TE_00CA8 | 1 | 9717.00 | 9717.00 | 4 Chip SI Modes | TE_00C62 | 2 | 19401.20 | 9700.60 | Totals: | 22 | 142867.40 | 6493.97 |
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.
All of the TE_00CA8s get counted as TE_007AE So watchout for TE_00B26 over-representation.
A word about the COLD Time stats:
Cold Time is defiined by focal plane temperatures <= -119.2 degrees C:
SI Mode Mapping between 6,5 and 4 chip modes:
The 6 chip SI Modes consist of three distinct modes. But there are only 2, 5 chip SI Modes and only one 4 chip SI mode. To make tracking feasible, the 4 and 5 chip modes were mapped into the 6 chip modes in the following manner:
6 chip 5 chip 4 chip
TE_007AC -> TE_00C60 TE_00C62
TE_00B26 -> TE_00C60 TE_00C62
TE_007AE -> TE_00CA8
Half of the TE_00C60s get counted towards TE_007AC and the other half get counted with the TE_00B26s
Half of the TE_00C62s get counted towards TE_007AC and the other half get counted with the TE_00B26s.SI Mode to Chip Mappings:
TE_007AC -> I0 - I3, S2, S3
TE_007AE -> S0 - S5
TE_00B26 -> I0 - I3, S1, S3
TE_00C60 -> I0 - I3, S3
TE_00C62 -> I1 - I3, S3
TE_00CA8 -> S1 - S5
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