User Workshop ESRIN 2005 - European Space Agency€¦ · Restituted Attitude Pitch Roll Yaw ... •...
Transcript of User Workshop ESRIN 2005 - European Space Agency€¦ · Restituted Attitude Pitch Roll Yaw ... •...
User Workshop ESRIN 2005
Anomaly Investigations
The following anomalies have occurred since Launch : • SDPSS DPC4 error
Anomaly Investigations
The following anomalies have occurred since Launch : • SDPSS DPC4 error• ENV-908 half OBT wrap around
Anomaly Investigations
The following anomalies have occurred since Launch : • SDPSS DPC4 error• ENV-908 half OBT wrap around• Unexpected SDPSS switch to pause mode
Trend charts optical bench temperature
• Over the complete analysed period of 36 months, the optical bench temperatures are stable within 1 LSB of 0.4 K
• The mean is stable within 40 mK, achieved due to big thermal inertia and standard ON/OFF heaters switching
• The thermal control loop is working perfectly
• The offset between the 3 THSS sensors is low (+/- 200 mK) and constant over time, which means that any of the three thermistorscould be used as backup in case of failure of one or two of them
Optical Bench Temperature trendsOrbital mean
19.2
19.4
19.6
19.8
20
20.2
20.4
20.6
01.03.02 01.03.03 01.03.04 01.03.05 01.03.06date
deg
C
E0095mean
E0096mean
E0097mean
R6082mean
Y1161mean
Optical Bench Temperature trendsTHSS Orbital mean
19.519.55
19.619.65
19.719.75
19.819.85
19.919.95
01.03.02 01.03.03 01.03.04 01.03.05 01.03.06date
deg
C
E0095mean
E0096mean
E0097mean
Trend charts CCD temperaturesCCD mean Temperatures trend
-22.501
-22.500
-22.499
-22.498
01.03.02 01.03.03 01.03.04 01.03.05 01.03.06
date
deg
C
E4520 mean
E4521 mean
E4522 mean
E4523 mean
E4524 mean
CCD 1,2,3,4,5 Temperatures trendOrbital min/max/mean
-22.6
-22.55
-22.5
-22.45
-22.4
01.03.02 01.03.03 01.03.04 01.03.05 01.03.06date
deg
C
E4520 min
E4520 max
E4520 mean
E4521 min
E4521 max
E4521 mean
E4522 min
E4522 max
E4522 mean
E4523 min
E4523 max
E4523 mean
E4524 min
E4524 max
E4524 mean
• The amplitudes of the CCD temperatures are about 60 mK p-p and stable over the 36 months period analysed.
• The variation of the orbital mean is per CCD temperature is extremely stable (less than 1 mK) along the last 36 months
• All 5 CCDs behave very similar• Thermal subsystem performance is stable and excellent
Trend charts peltier currentsMERIS Peltier current trends
Orbital min/max
00.10.20.30.40.50.6
01.03.02 01.03.03 01.03.04 01.03.05 01.03.06
Date
AM
P
E0134 min
E0134 max
E0135 min
E0135 max
E0136 min
E0136 max
E0137 min
E0137 max
E0138 min
E0138 max
MERIS Peltier current trendsOrbital mean
0.4
0.42
0.44
0.46
0.48
0.5
01.03.02 01.03.03 01.03.04 01.03.05 01.03.06Date
AM
P
E0134 mean
E0135 mean
E0136 meanE0137 mean
E0138 mean
• Min/Max temperatures are nearly constant and amplitudes within 200 mA p-p (Operational limit for spikes: 1.78 A)
• Maximum is stable (around 0.5 A) at and well below the monitoring limit of 1.6 A
• Orbital mean currents curves are stable within 5 mA (=1% of the value)
• No degradation of CCD thermal regulation loop
Trend charts VEU temperature
• Internal T VEU orbital amplitude (=max-min of E0190) always around 9K, = indication of good performance stability (offset & gain) of analogue electronics
• Strong correlation of mean, min, max and even standard deviation with the seasons is observed, which is explained by the seasonal variation of sun incidence angle on the +Y radiator (where the VEU is mounted on)
• Long term drift of mean temperatures by +0.5 K/year is not at all critical
• THSS sensors (E0080, 81, 82) behave very similar and any of them can be used as redundant sensor in case one of the three should fail.
• No significant degradation observed.
VEU mean temperatures trend
2222.5
2323.5
2424.5
2525.5
2626.5
27
01.03.02 01.03.03 01.03.04 01.03.05 01.03.06
date
deg
C
E0080 meanE0081 meanE0082 meanE0190 mean
VEU min/max Temperatures trend
15
1719
2123
25
2729
31
01.03.02 01.03.03 01.03.04 01.03.05 01.03.06
date
deg
C
E0080 min
E0080 max
E0081 min
E0081 max
E0082 min
E0082 max
E0190 min
E0190 max
Trend charts ICU controlled heaters current
MERIS ICU controlled heaters current trend
0
0.5
1
1.5
2
2.5
3
01.03.02 01.03.03 01.03.04 01.03.05 01.03.06
date
AM
P
E0120 minE0120 maxE0120 meanE0120 std
• Min always at zero, as expected• Max seem to decrease =>
probability that all heaters are ON at the same time (which is the driving event for max) decreases, which is good for thermal stress on the ICU heaters switching board.
• Operational limit of 5 A is respected with a comfortable margin.
• Mean is stable (apart from a slight expected seasonal variation)
• No degradation observed
Trend charts equipment pseudo power
Pseudo Power Equipment
5556575859606162636465
01.03.02 01.03.03 01.03.04 01.03.05 01.03.06Date
Wat
t
c
• Pseudo Power Equipment := DSU + SDPSS + VEU• Decrease due to Voltage decrease • Overall, boxes consumption is o.k. (< 60 W)
Life limited items - Diffusers
• Exposure is in line with the recommended calibration activities • Calibration frequencies and corresponding commanding of number of
frames parameter for the averaged frame in on ground calibrationmcmd can be continued nominally
• Limitation for Diffuser 2 has been relaxed to 90 min => large margin
MERIS Diffuser exposure to UV
0
1
2
3
4
0 5000 10000 15000 20000 25000orbits since launch
accu
mul
ated
hou
rsD
iffus
er 1
0
15
30
45
60
accu
mul
ated
min
utes
Diff
2 &
dop
ed D
iff
Diffuser 1Diffuser 2Doped Diffuser
Diffuser ageing
July 02 - May 2005
-0.90%
-0.80%
-0.70%
-0.60%
-0.50%
-0.40%
-0.30%
-0.20%
-0.10%
0.00%
0.10%
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
cam 1cam 2cam 3cam 4cam 5all
July 02 – May05
• Degradation limited to 560nm band and lower
• Instrument throughput degradation < 3% at 412nm
• No degradation for wavelengths above 500 nm
Mean Instrument degradation at orbit 18000 (mid August 2005)
0.97
0.975
0.98
0.985
0.99
0.995
1
1.005
0 2 4 6 8 10 12 14 16
Meris Band
dega
rada
tion
m1m2m3m4m5all
Instrument Degradation
Geolocation
Northern Hemisphere Southern Hemisphere
Restituted Attitude
Roll YawPitch
• Delivered operationally as of 31 Jan 2005 based on AOCS-Estimator output• Historical restituted attitude available as of 30 June 2005
Disparity analysis
Landsat ETM+ band 3MERIS band 7
MER_FS Geo-location
Before After
Offset Control Loop
OCL Has been switched to OFF on the 17 Dec 2004
Each point represents the blank value averaged on the entire orbit
All the orbits selected are located outside the SAA area
OCL-ON
OCL-OFF
OCL-ON
OCL-OFF
Impact of OCL-OFF
•Along track modulation have been removed.•Across track modulation due to calibration and degradation corrections
Conclusion
• The trends show a stable MERIS behaviour• Slight degradations (e.g. in VEU temperature) are not critical• Diffuser 2 exposure time has now a comfortable margin in the
allocation• MERIS is still (after more than 3 years) on nominal redundancy chains• The ENVISAT system has now implemented an restituted attitude
service• We are still improving the data products on a daily basis.