1. Summary on EFI splinter
I. Coco
5th Swarm Data Quality Workshop
Paris
10/09/2015

2. SUMMARY
Fruitful discussion: all the main points have been touched and discussed.
Thermal Ion Imagers (TII) related topics: data calibration, operational scenarios.
Langmuir Probes (LP) related topics: el. temp. discussion, sweep effects analysis, new datasets...
Validation of Swarm plasma data: progresses and new ideas.
Summary of Actions and Recommendations.
EFI status | I. Coco | Paris | 10/09/2015 | Swarm Data Quality Workshop | Pag. 2

3. TII discussion (1) Image anomaly and “ring feature”
Ring feature: Do not affect much science data (“cropped” away in processing)
Contaminated images: do affect science data
Contaminants and secondary populations (courtesy Torr Scientific)
EFI status | I. Coco | Paris | 10/09/2015 | Swarm Data Quality Workshop | Pag. 3

4. TII discussion (2)
Another possibility: “shocked” population of O+ (5 eV). More simulations needed and, possibly other independent validations of this hypothesis (TBD in future ARBs)
No further ideas for new tests, or other hints/suggestions to point the root cause of the anomaly came from the splinter...
EFI status | I. Coco | Paris | 10/09/2015 | Swarm Data Quality Workshop | Pag. 4

5. TII discussion (3): Operational scenarios
- Current situation:
Swarm A  4 orbits/day (consecutive)
Swarm B  2 orbits/day (consecutive)
Swarm C  ¼ orbit/day
Margins to extend A and B active state to 1-2 more orbits/day (tests on-going), no more than 1 orbit/day for Charlie (with some degradation already).
An automated “on-demand” Mission Planning Facility does not exist for Swarm: FOS can implement a “scheduled” mission planning cycle, with possibility to select start and stop times of the active states basing on latitude/local time. Once the schedule is commanded the same sequence is activated every day: sequences and schedules can be modified but this is a manual process, that should be limited to a reasonable minimum.
Problem #1: How do we decide the schedule? A huge number of orbits configurations interesting for science exists: inputs to be gathered throughout the science community.
Problem #2: How do we handle the schedule?  Procedures required (compilation and maintenance of a monthly/yearly operation catalogue through a decision board, updating of the schedule files for FOS), man power needed!
EFI status | I. Coco | Paris | 10/09/2015 | Swarm Data Quality Workshop | Pag. 5

6. TII discussion (4): Operational scenarios
Proposed solutions:
Scenario 0: a “routine” scenario should be established that will be scheduled to run as a default when no other tests or “special” campaigns/scenarios are foreseen. A Scenario 0 before the winter has been proposed by U.o.C.: “Active state of the TIIs on orbits above Millstone Hill radar field of view”. Details to be communicated to FOS.
“Test” Campaigns: 1-2 test campaigns will be defined in the coming months, i.e. special operations to be planned and scheduled in order to get familiar with procedures and evaluate the effort needed.
Discussion Group. A discussion group is established composed by representatives of: ESA, Univ. of Calgary (D. Knudsen, J. Burchill), IRF (S. Buchert, H. Opgenoorth), GFZ (C. Stolle, M. Foerster), FMI (K. Kauristie), Univ. of Oslo (L. Clausen), Institute of Space Physics of Romania (O. Marghitu), APL (J. Gjerloev). The main objectives are:
To gather information among their reference communities on suitable orbit configurations
To prepare a preliminary catalogue
To plan a test campaign (milestones not established, reasonably early 2016)
To draw sustainable “mission planning” procedures
EFI status | I. Coco | Paris | 10/09/2015 | Swarm Data Quality Workshop | Pag. 6

7. TII discussion (5): Operational scenarios
- Actions and recommendations:
First of all, before to plan anything, an ARB shall be scheduled in order to discuss the finalization of the tests on-going and the short-term way forward. FOS proposes Thu 17/9, 15:30 CET.
I. Coco is in charge to organize a “kick-off” of the discussion group by the end of September.
FOS to provide examples of the “Mission Planning” files to I. Coco and U.o.C. ASAP.
EFI status | I. Coco | Paris | 10/09/2015 | Swarm Data Quality Workshop | Pag. 7

8. TII discussion (6): Calibration
More accurate detector centers estimates based on fitting circles to TII ring anomaly
Using vertical sensor for along track flow
EFI status | I. Coco | Paris | 10/09/2015 | Swarm Data Quality Workshop | Pag. 8

9. TII discussion (7): Data & Algos
TII Preliminary data coverage
Still few 0201, with new estimates for detector centers
Need for new TII L1B algorithms:
Improved quality flags
Handle varying calibration parameters
Improve mixing of signals from the two sensors
EFI status | I. Coco | Paris | 10/09/2015 | Swarm Data Quality Workshop | Pag. 9

10. LP discussion (1): The electron temperature
There are differences between “blended” results and low gain probe results.
IRF will make available separate probe data as a priority.
EFI status | I. Coco | Paris | 10/09/2015 | Swarm Data Quality Workshop | Pag. 10

11. LP discussion (2): spikes and disturbances
Occasional spikes trains are observed, especially high-latitude (but C. Stolle reported about low lat occurrences during summer 2014)
Physical (environmental noise, plasma waves) or artefact? investigations needed
Possible correlations with accelerometers spikes?
Possible correlations with platform parameters (solar panel currents, MTQ activations)?
A preliminary list of occurrences will be made available soon.
FOS offered help in investigating platform correlations (an IRF assessment of possible dependencies is required)
EFI status | I. Coco | Paris | 10/09/2015 | Swarm Data Quality Workshop | Pag. 11

12. LP discussion (3): The Sweep effect on normal mode
A severe sweep cycle has been commanded on July 1st for 1 orbit on S/C a ([+5, -5] V)
Vsc hick ups after the sweep are enhanced by a factor of 2 or more.
UoC analyzed correlations with on-board 16 Hz moments of the TII: no correlations are found.
The Vsc (and Te) enhancements after the sweeps are clearly artificial (feedback effects on the electronics?) and not real effects of S/C charging.
They can be filtered away and/or flagged in data: future evolution of L1B processing.
EFI status | I. Coco | Paris | 10/09/2015 | Swarm Data Quality Workshop | Pag. 12

13. LP discussion (4): New datasets for expert users
- Faceplate currents: when FP is at negative bias (current set when TII is in ready state) the faceplate acts as a planar Langmuir Probe.
from FP currents, electron density and ion velocity can be potentially derived, at 16 Hz rate!
Several methods are being exploited, seems to work on event cases but not statistically...Strong assumptions involved.
- A dataset for expert users containing at least the “raw” FP currents at 16 Hz can be prepared soon and IRF will put priority on this
EFI status | I. Coco | Paris | 10/09/2015 | Swarm Data Quality Workshop | Pag. 13

14. LP discussion (5): New datasets for expert users
Other datasets/auxiliary data:
1. Sweep mode: plasma parameters derived from the Sweep mode have now been highly improved but still they don’t match with those from the harmonic mode. Statistical analysis of the sweep data could be very interesting in a validation perspective (we do not actually know which dataset is “better”).
2. Auxiliary data: database available at IRF containing magnetic coordinates (quasi dipole coordinates, but AACGM can be added), magnetic local time, apparent solar time.
EFI status | I. Coco | Paris | 10/09/2015 | Swarm Data Quality Workshop | Pag. 14

15. LP discussion (6): L1B data distribution
Plasma Level 1B “official” products (EFIx_PL_1B) will be still available soon (~/Current folder of the ESA FTP server), and are meant as a continuation of the LP preliminary dataset (~/Advanced folder).
The OP and PREL datasets are interoperable: Ne, Te and Vs can be used together, but keep in mind differences in format exist between the two datasets. Read carefully the user note on the web:
The TII parameters in the OP data will be set to zero. TII data will still be made available by UoC as a preliminary dataset (~/Advanced folder)
LP quality flags are artificially set to 20 (data to be used with caution): IRF is reviewing the flags concept in order to give users a clearer picture of the data quality.
EFI status | I. Coco | Paris | 10/09/2015 | Swarm Data Quality Workshop | Pag. 15

16. Data Validation (1): ISR comparisons
IRF analysis seems to confirm an overestimate of the LP temperatures but...
Distribution is still sparse, more statistics needed; moreover radar data should be selected carefully.
- GFZ offered help in pursuing the ISR vs Swarm validations (dedicated students programs, PhDs...)
EFI status | I. Coco | Paris | 10/09/2015 | Swarm Data Quality Workshop | Pag. 16

17. Data Validation (2): Other independent analyses.
The comparison with the empirical ISO-standard model IRI-2012 (International Reference Ionosphere) suggests that Swarm Ne values are too low by about 10%-15%
The Te values are, compared with the IRI-2012 values too high by either ~10%, or in a second peak appearance by >50% (or ~ 1500 K)
The “Bifurcation” of the Swarm Te values are most likely due to the use the two LP's, operating in different modes (high and low gain), and “blended” during data analysis,
There are regular unusual peak values of the fp (plasma potential) and Te (electron temp.) values under daylight only that appear to be related to the sun's position w.r.t. the S/C
These disturbances can also be traced as enhanced fluctuations in the Ne (electron dens.) values, which could be misinterpreted as natural plasma phenomena (e.g., “bubbles”)
M. Foerster
EFI status | I. Coco | Paris | 10/09/2015 | Swarm Data Quality Workshop | Pag. 17

18. Data Validation (3): Other independent analyses.
EFI status | I. Coco | Paris | 10/09/2015 | Swarm Data Quality Workshop | Pag. 18

19. Summary of Actions and recommendations
TII:
Discussion group on orbit configurations up and running
New ideas for the image anomaly investigation to be pursued: simulations, help from other communities within ESA (e.g. Cluster)
LP:
Advanced datasets to be released soon (by end October): Te single probe, FP currents. On best effort others will follow (sweeps, auxiliary etc...).
IRF/UoC to provide ESA (FOS, I. Coco) lists of spikes occurrences in order to start combined investigations.
Validation:
GFZ will provide help in increasing ISR based studies and statistics,
New initiatives and other on-going activities to be monitored: science teleconf. will be organized again by I. Coco, trying to focus them more on validation aspects.
EFI status | I. Coco | Paris | 10/09/2015 | Swarm Data Quality Workshop | Pag. 19