1. CAA Operational Review 9 Double Star PEACE Team Report
A.N. Fazakerley, B. Mihaljcic, N. Doss, C. Annekallu, Y. Bogdanova, G. Watson.
MSSL-UCL
Operational Review Meeting – 9 ESAC 04 June 2014

2. Personnel No formal funding for Double Star archiving activities
Same team as for Cluster archiving work, but Branislav has done the vast majority of the Double Star work in recent times

3. Summary Delivery of PITCH_SPIN data for both spacecraft for all years
Preparation of Caveats dataset
Significant efforts to optimise quality of delivered data, overcoming challenges of noisy and/or incomplete raw data

4. Status of software development (1)
Production Software – PITCH_SPIN
PITCH_SPIN CAA data is produced twice, once for each raw dataset
Merging software picks the best data spin-by-spin to produce final file (using G version unless the other is better)
7 types of problem (usually due to poor raw data quality) identified and handled
The following slides illustrate these points
Status of software development (1)

5. PITCH_SPIN production process
3DF data (O version, IDFS)
Ground made PAD (O version, IDFS)
3DF data (G version, IDFS)
Ground made PAD ( version, IDFS)
CAA Format Data
(232)
CAA PITCH_SPIN
data ‘O’ version
data ‘G’ version
Merged data
(spin-by-spin)
Spin Origin (G or O)
Corrections may be needed at any of these stages
Successful PITCH_SPIN production implies that 3DF data problems have also been solved

6. Merging of CAA files produced from “O” and from “G” version of raw data at spin level
CAA PITCH_SPIN data [‘O version’]
CAA PITCH_SPIN data [‘G version’]
CAA PITCH_SPIN data
(produced by taking best spins from either ‘O’ or ‘G’ version)
The merging code can handle, missing, incomplete and shifted spins if they occur in any of the datasets then choose the best one for the final CEF file.

7. Correction of PITCH_SPIN production errors
BEFORE: TC-1 PITCH_SPIN CAA format Data AFTER: TC-1 PITCH_SPIN CAA format Data
PITCH_SPIN data
PITCH_SPIN data
The DS or DS_rp IDFS 3DF data had no problems.
PITCH_SPIN data plots (LHS plot), had problems below ~700 eV as RPAD had problems
REASON: For such cases the RPAD production code was missing the start or end timestamp due to a corrupt data stream.
We fixed the problem and regenerated DS and DS_rp RPAD to make correct PITCH_SPIN (RHS plot)

8. Correction of PITCH_SPIN production errors : TC-2 preset problem in raw 3D data (aa mode)
(232) Corrected
3DF data O version
3DF data G version
3DF data O version
3DF data G version

9. Correction of PITCH_SPIN production errors
In this case the CAA production code can be adjusted to make a good CAA CEF file
The recipe file that the CAA code makes ensures that in this case spins only from fixed DS data is used to make final CAA file (here version ‘M’)
PITCH_SPIN data ‘O’ version
(low and high energy sweep preset FIXED 100%)
PITCH_SPIN data ‘G’ version
(only low energy sweep could be FIXED 100%)
PITCH_SPIN Merged data
(The merged data set is 100% FIXED)
Spin Origin
(233)

10. 2004-08-21 (234) Correction of PITCH_SPIN production errors
In this case only the O ver high energy sweep is ok (see panel 1)
and
only the low energy sweep from G ver is ok
(see panel 2)
The CAA production code can be adjusted to take only :
O ver: high energy sweep from panel 1
G ver: low energy sweep
from panel 2 to
make the final CAA file shown in panel 3
Hence data from alternate files is taken as shown in panel 4
PITCH_SPIN data ‘O’ version
(only HIGH energy sweep could be FIXED 100%)
PITCH_SPIN data ‘G’ version
(only LOW energy sweep could be FIXED 100%)
PITCH_SPIN Merged data
(The merged data set is 100% FIXED)
Spin Origin
(234)

11. 2004-08-20 (241) Correction of PITCH_SPIN production errors
In this case only the DS data is used to make the correct CAA CEF for a case when there are data gaps.
PITCH_SPIN data ‘O’ version
(HIGH and LOW sweeps 100% FIXED)
PITCH_SPIN data ‘G’ version
(LOW sweeps 100% FIXED)
PITCH_SPIN Merged data
Spin Origin
(241)

12. Example of delivered PITCH_SPIN data with multiple gaps due to gaps in raw data
CAVEATS and possibly Status flags will inform the user that these are “real” data gaps that cannot be fixed.

13. Status of software development (2)
Production Software – 3DX
3DX CAA production code complete, merging software ready
Production Software – SCPOT
Algorithm available, may try to improve; specific CAA production code tbd
Production Software – Moments
production software exists, merging software to be produced,
accuracy will be affected when no spacecraft potential estimate can be produced
Production Software – Caveats
production software exists, may update to indicate days with multiple gaps
(Limited progess on Status parameters)
Status of software development (2)

14. Status of calibration and cross-calibration activity
It is difficult to perform in-flight cross-calibration for the PEACE instruments on the Double Star spacecraft.
There is no direct measurement of spacecraft potential, so determination of PEACE moments is only possible if one may estimate the spacecraft potential from PEACE spectra (i.e. if the energy range covered the photoelectrons).
Even when PEACE moments can be produced, there is a problem because there is no absolute density reference (such as is provided by WHISPER on Cluster) – HIA on TC-1 is not suitable, nor LEID on TC-2.
There are no convenient close conjunctions with other spacecraft that might provide a useful reference either.

15. Data delivery status TC-1 UPDATED since the written report 2 weeks ago
TC-1 UPDATED since the written report 2 weeks ago
(data not delivered where JPEG compression mode was not used - rare)
TC2 UPDATED since the written report 2 weeks ago
Data delivery status
Product name
2004
2005
2006
2007
2008
MOMENTS
n/a
PITCH_SPIN D
3DX
3DX-LAR (rare)
SCPOT
Product name
2004
2005
2006
2007
2008
MOMENTS
PITCH_SPIN D
3DX
3DX-LAR (rare)
SCPOT

16. Data delivery plan Logical Sequence (timing tbc) 3DX and 3DX-LAR data
Logical Sequence (timing tbc)
3DX and 3DX-LAR data
following merging software provision
(note the files are so large that they must be delivered in 2 hour parts, so production/delivery may be time consuming)
SC_POT
following completion of production code
Moments
production code exists but importantly we need to ensure the quality flag highlights intervals where SC_POT is unavailable (lack of potential is less important for plasmasheet than for solar wind/magnetosheath)
Caveats
following completion of data gap warning code based on existing software that estimates number of gaps per day, may also indicate days lacking estimated spacecraft potential data
Data delivery plan

17. Estimating spacecraft potential from PEACE data (suitable energy spectra)
TC1 ( ) 3DF 05:00-06:00
electrons
Plasma
electrons
Photo
Automated software s/c potential estimate
Clear distinction between the photo-electron and plasma electron populations
Spacecraft potential (black line) can be estimated from PEACE data.
We don’t claim this estimate is perfect!
In this case relatively accurate MOMENTS can be produced.

18. Estimating spacecraft potential from PEACE data (unsuitable energy spectra)
TC1 ( ) 3DF 13:00-14:00
electrons
Plasma
Electrons?
Photo
In this case there is only the plasma electron population, but no photo-electron population
Hence, no s/c potential estimate can be made from PEACE energy spectra.
Moments accuracy is reduced
Last of potential data less serious when plasma is at high energies, e.g plasmasheet .

19. Data re-delivery plan Aspirations (timing tbc) PITCH_SPIN data
Aspirations (timing tbc)
PITCH_SPIN data
possibly we will regenerate using new CAA FGM dataset (present version uses TC-1 spin rate FGM data and TC-2 FGM CoI FGM data)
All datasets
possibility of regeneration if calibration knowledge is improved
Data re-delivery plan

20. Documentation The CAA has these documents:
User Guide to the PEACE measurements in the CAA – in draft form
Calibration Report of the PEACE measurements – not available
Interface Control Document for DS PEACE in the CAA V3.0
The PEACE team CAA-related papers: 
Paper on Double Star calibrations in preparation
The CAA Documentation page does not (but could) provide a link to the PEACE Operations History webpages.
Documentation

21. Replies to OR8 (and earlier) Recommendations
OR4- R18 to all teams and CAA: Double Star, the first bilateral mission between ESA and China, ceased collecting data in 2008, and the existing data currently resides with the individual instrument teams in Europe and China. Without proper archiving of the Double Star data it will eventually be lost to the scientific community as has happened many times in the past with previous space missions. The board is aware that activities to ingest Double Star data into the CAA have begun, as recommended in OR3. However, the board fears that in the absence of additional funds for the CAA to complete this work, this important activity will fail. The quality of the data ingested cannot be guaranteed without proper investment in calibration and data validation activities. Without extra funding, some of the instrument teams will be unable to provide their data to the CAA. The board urges that the CAA seek additional support to continue quality assurance and archiving of the Double Star data
PROPOSE TO CLOSE
No extra funding has been made available. Nevertheless, we have reached the stage of beginning data deliveries.

22. Replies to CC19 Recommendations
CC19-AI-01 to All: Check that the headers are complete and correct. This concerns particularly various descriptions in different levels (experiment, instrument, dataset).
PROPOSE TO CLOSE
The experiment/instrument/dataset description headers for Double Star have been checked and updated where necessary. The main change was to update addresses. Updated headers have been submitted to CAA
CC19-AI-07 to PEACE: to provide the DWP team with a source code of the software required to read PEACE HK data (both CLUSTER and DOUBLE STAR)
We have provided the required software and DWP have confirmed that it was effective.
CC19-AI-17: to deliver the annual report and ICD on the Double Star datasets for the OR-9 review
This document is the annual report.
The ICD was not updated.

23. Replies to CC19 Recommendations
CC19-AI-18: to deliver the Double Star datasets of to the CAA.
IN PROGRESS UPDATED since the written report 2 weeks ago
PITCH_SPIN has been delivered for all years for both spacecraft. More datasets will follow.
CC19-AI-21: to investigate if their processed data and PP are shifted in time in Sep 2006 and 1-30 Nov 2006
PROPOSE TO CLOSE
This has been investigated and no such time shift has been observed in PEACE data.

24. END