FGM report 10 th Cross calibration workshop Elizabeth Lucek, Patrick Brown, Chris Carr, Tim Oddy, André Balogh I mperial College London November 2009

Primary FGM data delivered to CAA: Feb 2001 – April 2008, June 2008 –Magnetic field data: Full resolution, 5 vectors/second, spin averaged –Supporting files: GAPF (data gaps in processed data); VALF (data gaps introduced at validation stage – small number, generally only affects a few vectors at a time) Supporting FGM files delivered to CAA: Feb 2001 – Dec 2006 –CAVF: caveat files provided only when data quality is affected by external effects –CALA: calibration accuracy files Outlook –Several problems over the last year –Routine data delivery has recommenced - data from June delivered yesterday –Expect to deliver data from May – Oct 2008 by Christmas 2009 CAA status of data submission 2 Management changes Paul French left the team on October 16 th 2009 Archiving tasks currently divided among other team members

FGM CAA documentation Sources of documentation for FGM and FGM data –Interface Control Document (ICD) New ICD delivered to the CAA (CAA_FGM_ICD_0002_V0_4) –FGM User Guide V 1.0 delivered to the CAA in January 2009 –Cross-Calibration report V 1.0 delivered to the CAA in January 2009 –Some updates to be made in response to Peer Review recommendations Description of calibration procedure –Finalised paper prepared for proceedings of Tenerife workshop 3

Problems I Range 6 –FGM enters Range 6 within auroral acceleration zone –R6 implemented in electronics, but no ground calibration –DP modules updated (many thanks to Edita) –New calibration parameters have been derived for all four spacecraft using data from January 2009 Some additional testing required Browse data can be prepared on event-by-event basis –Updates to FGM DP software, implementation of R6 processing in PSDS/PP Full integration clearly highly desirable Requires CoI input – Karl-Heinz Glassmeier, Edita Georgescu, Karl-Heinz Fornacon Being considered Feasibility/timescale TBC 4

FGM R6 recalibrated data 5

R6 FGM comparison with WBD 6 White: FGM Black: IGRF Further testing needed Agreement is encouraging

Problems II Poorly determined spin axis offset –Effect: up to 1 nT discrepancy in B in solar wind –Data affected: Mar 2002; First half Jan 2003; First half Feb 2003 –Thought to arise from either: Error in application of solar wind calibration (Jan, Feb 2003) Insufficient solar wind data to yield good spin axis offsets (Mar 2002) –V02 data from Jan and Feb 2003 prepared –CAVF files for March 2002 prepared –Data will be checked and delivered when time allows –OPEN Outstanding CAVF and CALA files for Jan 2007 – April 2008 –Delayed by ssh problem –Data prepared when time allows –OPEN 7

Other Issues – medium priority Verification that CAA has complete data set –Before the end of the Active phase of the CAA, a check between the CAA and Imperial inventory will be made to ensure that all data have been delivered –OPEN Routine generation of CAVF files –Most of the software is written –Redelivery of all CAVF files would be straightforward once procedure finished –OPEN Delivery of data from Nov 2000 – Jan 2001 –Plan to deliver data from this period –Will use cut down calibration procedure –OPEN 8

Lower priority issues Preparation of data for summer 2001 incorporating inter-spacecraft calibration –Significant improvement not found to date –ON HOLD Calibration refinement files – for use in following changes in calibration parameters in a single orbit –Software written and tested, but not ready for routine use –ON HOLD 9

2009 CAA Peer Review Recommendations to all teams - I PR09-ALL01 – UG should illustrate instrument issues. –Propose to add some figures to the UG residual spin tone in the data residual jump at a range change spectral signature of residual tone at the spin frequency and twice spin frequency, also showing that single calibration file cannot always fit the data from a full orbit PR09-ALL02 – Caveat information –Caveat information routinely produced covering interval affected and likely cause if known PR09-ALL03 – ICD updates –FGM ICD updated to include CALA file description. Will consider the need for a further update before end of CAA PR09-ALL04 – Spacecraft-intercalibration –Some routine measures, e.g. when spacecraft are in solar wind –Results included in Calibration Accuracy (CALA) files –Formal intercalibration infrequent - special conditions required 10

2009 CAA Peer Review Recommendations to all teams - II PR09-ALL05 – Discussion of data errors/standard deviations –Qualititative estimates of data quality and quantitative measures are included in the CALA files PR09-ALL06 - A mission-long assessment of inter-calibration fidelity is missing from the calibration reports. –Analysis of the CALA files will be included in the calibration reports if time allows PR09-ALL07 – Documentation of physical region – instrument mode mismatch issues –FGM does not suffer from these effects PR09-ALL08 – Differences between CAA ‘simple’ and ‘advanced’ interfaces –FGM data are straightforward enough that we anticipate that the two interfaces will be the same PR09-ALL09 – Inclusion in Calibration Report of CAA generated cross calibration plots –We are not currently aware of any proposals of this nature for FGM 11

2009 CAA Peer Review Recommendations to all teams - III PR09-ALL10 – Discussion of use of PP/CAA data –PP data included for completeness PR09-ALL11 - Digital versions of calibration results presented in the calibration reports should also be archived at the CAA. –Not currently applicable to FGM since results derived results from calibration files are already archived in the CAA PR09-ALL12 – All reference documents referred to in the UG should be available at the CAA –All FGM references are publically available. PR09-ALL13 – The UG should contain a table of all datasets in the CAA –This table will be included in the next version of the FGM User Guide. PR09-ALL14 – All teams should include some flags in their data to indicate usability –Changes to FGM data products (FULL, 5VPS, SPIN) not feasible at this stage –Calibration accuracy files contain parameters summarising the usability of the data for different types of science. 12

2009 CAA Peer Review Recommendations to FGM - I PR09-FGM01 – UG should show how to identify data intervals with range changes, interference and spin modulation –These effects are already explained in the User Guide, but additional figures will be included as listed in the response to PR09-ALL01 PR09-FGM02 – A description is needed of the Calibration Accuracy files –A description is already included in the UG but some additional information on interpreting the ‘score value’ will be included in the next update PR09-FGM03 – The FGM team should try to provide a plan for long-term calibration issues such as instrument drifts –Long term drifts in instrument calibration parameters are accounted for in the routine calibration, and no further action is required PR09-FGM04 – PP data should not be included in the CAA –PP/UP data have been widely used, so it is essential that they are archived. However, we recommend SPIN for new studies PR09-FGM05 – Variances should be included in 5VPS and SPIN –With hindsight inclusion of the variances might have been useful, changes to the CAA datasets (FULL, 5VPS and SPIN) are not feasible at this stage 13

2009 CAA Peer Review Recommendations to FGM - II PR09-FGM06 – Quality flags and range information should be added to each record –We do not think that meaningful quality flags can be applied vector-by-vector to the FGM data –The instrument range and mode (normal or burst mode) are already supplied as part of every data record. PR09-FGM07 – FGM should be provided in ISR2 –If co-ordinate transformations are required for data products from more than one instrument we suggest that it would be better included as part of the CAA interface PR09-FGM08 – For SPIN and 5VPS the metadata should contain an entry describing how the averaging is done –This information will be included – averaging is done using a boxcar average. PR09-FGM09 – On the CAA Web page the dataset description for the CALA files is missing –This description has been supplied to the CAA 14