1. MsWG (Apr 22, 2015) Recent L1B LUT delivery since April 8, 2015
Aqua C6 forward update: (4/20/2015) TEB default b1
Aqua C5 forward update: (4/21/2015) TEB default b1
Terra C5 forward update: (4/16/2015) RSB m1, sigma_m1 and RVS, TEB & QA
Terra C6 forward update: (4/17/2015) RSB m1, RVS and uncertainty & QA
Terra C6 OBPG update: _OC2 (4/22/2015) RSB m1, RVS and uncertainty
MODIS instrument status
Terra and Aqua MODIS are in nominal operations
Aqua IAM #46 successfully completed: 2015/105 15:16:28 – 16:02:48
Aqua IAM #47 scheduled for 2015/112 (4/22/15) ~15:33:28
Terra DMU #91 scheduled for 2015/112 (4/22/15) ~14:01:50
MCST recent Activities
Sector Rotation Code Fix delivered C5/C6
Terra B36 D7 QA (slides 2-6)
Aqua CFPA Discussion (slides 7-21)
Around the table
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2. Terra B36 D7 QA
Terra Band 36 Det. 7P.O. had previous similar occurrences reported anomalies (for list refer next slide)
Anomaly Type: Electronic Formatter Error
Starting from 2015/092 17:40(GMT) BB DN, SV DN values flip between 4095 and 0
Behavior continues as of today (2015/112)
Exact cause of behavior is unknown No
Anomaly Periods
Time in Day/Hrs 1
2008( )
~1D and 10H 2
2008( )
~ 1D 3
2010( )
~2D and17H 4
2010( )
~2H 5
2011( )
~7H 6
2011( )
~6H 7
2011( )
~14 H 8
2011( )
~4H 9
2012( )
~5H 10
2012( – )
~44D 11
2014( – )
113D+ 12
2015( – present)
20D+
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3. Daily b1 and NEdT Trending
b1 / NEdT trending for
17:40:00 (GMT)
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4. Daily DN BB & SV trends (2015/092)
<DN_SV>
dn_BB
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5. Daily DN BB & SV trends (2015/104)
<DN_SV>
dn_BB
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6. Summary and Recommendation
Terra Band 36 Det. 7 has exhibited anomalous behavior beginning through the present, over 14 days continuously. The result is a number of invalid scans (striping) in the L1B product.
Based on previous instances the QA flag was changed from ‘noisy’ to ‘inoperable’ for this detector in C5/C6 from forward.
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7. Aqua MODIS Cold FPA Performance and Operation
MODIS Characterization Support Team (MCST)
April 22, 2015
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8. Outline Introduction On-orbit Performance Update Observed Impacts
Mitigation Strategies
Summary
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9. Introduction Aqua MODIS Cold Focal Plane Temperature Control
Known issue with decreasing radiative cooler margin
Prior meetings held to brief science disciplines on status, impacts and possible mitigation strategies
1st meeting on May 7, 2010
2nd meeting on April 25, 2012
3rd meeting on March 17, 2013
4th meeting on April, 16, 2014
MCST continues to monitor instrument performance
Impacts observed that can affect science products
Orbital variation in TEB detector gain (PC bands more sensitive)
Increased fitting residuals from BB WUCD during a0/a2 derivation
Saturation in bands 33, EV data during WUCD
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10. Current Status
CFPA temperature peak during summer months with maximum ~83.7 K in mid-2013.
Peak temperature has decreased in 2014 and 2015
CFPA orbital/seasonal oscillation – max/min difference ~0.4 K
Radiative cooler margin lost for CFPA setpoint of 83 K during intermittent periods through annual cycle.
Majority of impacts on L1B products occur during BB Warmup/Cooldown activities
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11. BB Temp Trends Terra Aqua 25 mK 5 mK
Weekly average (Cal events excluded)
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12. Warm FPA Temperatures Terra Aqua ~3.5K increase over 15+ years
Weekly average (Cal events excluded)
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13. Cold FPA Temperatures Terra Aqua Weekly average (Cal events excluded)
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14. Aqua CFPA Oscillations Long-term trend
Max/Min of 4 orbits
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15. Aqua CFPA Oscillations Long-term trend
Max/Min of 4 orbits
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16. Aqua CFPA Oscillations Short Term (DOY 100) trend
2003
2009
Max ~83.0 K
Max ~83.1 K
SMIR
LWIR
2010
2011
Max ~83.15 K
Max ~83.2 K
Granule average
x-axis = granule #
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17. Aqua CFPA Oscillations Short Term (DOY 100) trend
SMIR
LWIR
2012
2013
Max ~83.3 K
Max ~83.4 K
2014
2015
Max ~83.3 K
Max ~83.25 K
Granule average
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18. Heater Voltage Trend
CFPA temperature not controlled for intermittent periods
1 orbit average
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19. Observed Impacts Improved temperature performance since last meeting
Gain variation with CFPA temperature
captured by scan-by-scan calibration
PC bands show largest effect
Linear relationship between gain and CFPA Temp
BB Warmup-Cooldown Activities
Larger residuals for a2 derivation (a0 = 0 for PC bands)
Temperature correction for a0/a2 analysis implemented in C6
Bands 33, 35 & 36 TBB Saturation
Increased instances of EV saturation
Cumulative saturation during WUCD:
2004/203 - B33: 0 min., B35: 0 min, B36: 0 min
2009/123 – B33: 7 min, B35: 13 min, B36: 0 min
2013/174 - B33: 200 min, B35: 95 min, B36: 37 min
2015/032 - B33: 161 min, B35: 105 min, B36: 37 min
FPA temperature dependent default b1 algorithm implemented for C5/C6
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20. Mitigation Strategies
Options under consideration to address temperature fluctuations
No change – continue operations in current configuration
Change CFPA set point to 85K
Perform Outgas (requires NASA HQ approval)
Reduce frequency of WUCD activities
Upload modified DCR table for bands 33, 35 & 36 (reduce saturation during WUCD) – may impact dynamic range for bands
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21. Summary Aqua MODIS continues to operate nominally
A decrease in radiative cooler margin has been observed since ~2007.
CFPA temperature not able to be stably controlled at set point of 83 K
Orbital and seasonal variations observed
Maximum SMIR temperature reached in mid-2013, temperature performance has improved since then
Scan-by-scan calibration captures much of the impact of the CFPA variation
Collection 6 includes an improved default b1 algorithm and temperature correction to the a0/a2 analysis.
EV saturation for bands 33, 35 & 36 during WUCD activities continues.
MCST continues monitoring of CFPA performance. No reports received of adverse impacts on science products.
MCST Recommendation: Option 1 – No change in operation status
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22. Backup Slides
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23. Option 2 – Change CFPA Set Point to 85K
S/C needs to be in “nominal mode” for this activity
Ensure that CFPA heater B is in the ON state
Send the following commands:
SET_RC_CFPA_TEMP TO 1/2/3
MOD_SET_PM_RC_CFPA_TEMP(‘T2’)‏
Monitor telemetry to ensure that the CFPA temperature adjusts accordingly (real time until it stabilizes)
Advantages:
Gain stably controlled
EV saturation during WUCD decreased
Increase in dynamic range for some TEB
Concerns:
Majority of pre-launch LUT tables based on 83 K set point
DCR table for 85 K
Decreased radiometric resolution for some TEB
Increased detector noise
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24. Option 3 - Outgas
An outgas without an anomaly requires transitioning MODIS from science mode to standby mode and then to outgas mode
Doors are closed, except SV door is moved to outgas position
This operation/action may require approval from HQ
An outgas requires a set of commands and takes 2-3 days to complete (heaters are turned on in specific sequence)
CFPA will be back to ambient temperature during outgas operation
Potential impact on SWIR (band 6 in particular) detector operability
IOT prepared for and has approval to perform an outgas in the event of spacecraft anomaly resulting in a safe mode transition.
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25. Option 5 – Modify DCR Table
CFPA setpoint remains at 83 K
DCR table for bands 33, 35 & 36 modified and uploaded
Expected to reduce EV saturation during WUCD
Can be performed by IOT as a regular table upload to MODIS.
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