PEACE DAA Status Andrew Fazakerley, Iryna Rozum, Andrew Lahiff, Branislav Mihaljčić & the PEACE ops team 5 November 2009, DAA meeting, Paris, France MSSL

Progress (1) MSSL Work on product definition and header/data file design is in progress Delivered draft test cef 3DR, 3DX and PADMAR files and headers, and updated draft ICD before Qingdao meeting Telecon with DAA/ESTEC 13 October 2009 to make some decisions on proposed data products (options were outlined in draft ICD) Received review of draft ICD received from the DAA 20 Oct 2009 – the ICD will be updated accordingly, and in line with agreements from telecon.

Progress (2) MSSL Production code adaptations following telecon decisions are in progress (e.g. “3DF” => “3DX”, “RPAD” =>”PITCH_SPIN”) Review of incomplete draft headers and provision of corrected headers by ESTEC received 28 Oct But updated headers were also being created in parallel at MSSL following the telecon. The MSSL and ESTEC header versions agree apart from an additional status_eclipse variable which has been added to MSSL versions. Header design is still incomplete while fine tuning of the data product design (by A Lahiff) is incomplete (e.g. may alter further status parameters; how to handle alternating spins, need for match between headers and data file contents)

Progress(3) MSSL MOMENTS generation code is in progress (again, header/data issues) Validation codes are not yet prepared “Plotcf” code needs to be updated to work with these data, as part of validation tools Work in progress in more effective spacecraft potential estimation No new work on calibration yet – inter-anode calibration needs to be extended to 2007 (TC-1 and TC-2) and 2008 (TC-2 only) No work done (if needed) to ensure production software stable when processing “noisy” data.

Progress(4) MSSL Proposed timetable is probably achievable using present calibration and estimated potentials, but subsequent re-processing and re-submission may be appropriate in that scenario. Plan to handle resets, and other problems with status flags similar to Cluster methods. No special work done for DS, but likely to be needed. May require generation of large event files which could be laborious. (Do we need a mission-level flag for time intervals where noisy data is occurring?)

Progress(5) MSSL Current planned products: 3DX, is the usual product from the spacecraft (and 3DX_LAR). Big files. PITCH_SPIN, made from 3DX and FGM data on ground. Good for browse. 3DR and PADH/M/LAR, only when produced onboard which is rarely SCPOT, spacecraft potential estimated from PEACE data where possible Moments (and DSDS data) Possible additional products (lower priority): ES from HK; NOI from HK PITCH_3D similar to Cluster; may make PITCH_SPIN from PADH/M/LAR Mode information; Modified magnetic field data used for TC-2 PITCH_SPIN

Introduction: PEACE MSSL PEACE – Plasma Electron And Current Experiment – measures the three dimensional velocity distribution of plasma electrons, for an energy range from 0.6 eV to ~ 26 keV Cluster: HEEA and LEEA on each spacecraft HEEA – high energy electron analyser LEEA – low energy electron analyser Double Star: TC-1 – HEEA & TC-2 – LEEA Full measured energy range is divided into 88 levels, each sensor can sample a group of 30 or 60 energy levels

Introduction: PEACE MSSL Cluster: full energy coverage is achieved by using two sensors together Double Star: Alternating energy coverage on alternate spins usually, or steady coverage in a restricted range – need two spins to get full energy coverage When using “alternating” mode, the Moments and PITCH_SPIN are made every spin, using data from two spins in a sliding window process. Thus a missing spin in TM affects more than one spin in Moments & PITCH_SPIN

What is produced on-board Double Star? MSSL HEEA TC-1 LEEA TC-2 Sensors collected data 3DF 3DF (full 3DX) 3DR, PAD DPU secondary code primary code, jpeg compression PEACE telemetry Spacecraft Secondary code was run rarely => very little 3DR and PAD data.

MSSL Science Data Products: 3DX & 3DR Proposed PEACE Data Products in DAA

PEACE Data Products in DAA 3D distributions MSSL 3DX, 3DX-LAR Based on the 3DF IDFS files. It contains full resolution 3-D data from PEACE 3DF (via JPEG compression, different to Cluster): The LAR mode option will be needed rarely TC1: 28 Feb 2005 – 07 Mar 2005 When DS PEACE is operating in “ab” mode the data record for every second spin will be half filled with fill values Files for a day may be very large; to keep them under 1 GB, may use smaller tha 1 day as baseline filesize NOTE: IDFS 3DF product is called full DAA 3DX just like for CAA

PEACE Data Products in DAA 3D distributions MSSL 3DR Based on the 3DR IDFS files. It contains standard reduced resolution 3-D data: Prepared using the best available calibrations Since very little 3DR data was manufactured in DPU, the DAA 3DR data products will be rarely available

MSSL Value-added Science Data Products: MOMENTS, PP Moments, PITCH_SPIN, SCPOT, PASMF

PEACE Data Products in DAA MOMENTS & PP Moments Data MSSL MOMENTS Will be based on transmitted 3D data Will be prepared using the best calibrations and taking into account the estimated spacecraft potential Photoelectrons will be removed where necessary Production code is in development, will be peacemoments based like on Cluster Will be very similar to CAA MOMENTS, but probably less different status words Time periods with uncertain potential will be flagged with a warning flag PP Moments Data From DSDS This data product will either be the same as MOMENTS or less accurate

PEACE Data Products in DAA PITCH_SPIN MSSL PITCH_SPIN It contains re-binned pitch angle data: Based on RPAD IDFS files which are made from IDFS 3DF and DFUNIT data It covers the 180 o pitch angle range in 12 sectors of 15 o each Each data spin is used twice in producing RPAD, averaging where there is an overlap in energy between spins This is the recommended pitch angle data set for scientific use NOTE: PITCH_SPIN used to be called RPAD; this is not the same data product as PITCH_SPIN for CLUSTER!

PEACE Data Products in DAA P & PASMF MSSL SCPOT It contains estimated spacecraft potential data: Based on DPPOTSC IDFS files Generated using PEACE energy spectra The process is automated with some human validation The algorithm does not handle well some plasma distributions Lowest measured energy is not always below the spacecraft potential – difficult to estimate potential PASMF It contains pitch angle support magnetic field data based on DFUNIT IDFS files We recommend not to include this data product, despite earlier idea, as we don’t have CFUNIT in the CAA

MSSL Pre-science Data Product: PAD

PEACE Data Products in DAA 2D distributions MSSL PAD, PAD-LAR/MAR/HAR Based on the PAD IDFS files. It contains on-board selected pitch angle distribution data: Will be rarely available 24 polar bins per spin like on Cluster Not the recommended data product to access pitch angle data NOTE: we might decide to make PITCH_SPIN from PAD (TBD)

MSSL Diagnostics Data Products: ES1-D Energy Spectrum and PS1-D Anode Spectrum

PEACE Data Products in DAA Diagnostics (TBD) MSSL ES1-D Energy Spectrum Based on the DPENERGY IDFS files. Counts per spin summed over all azimuth and polar bins, for each energy bin Derived from HK telemetry Gives an idea of the energy spectrum of the plasma at times when SCI telemetry is not available Does not exist for Cluster PS1-D Anode Spectrum Based on the DPPOLAR IDFS files. Counts per spin summed over all azimuths and energy bins, for each anode Derived from HK telemetry Unlikely to be used for science Was originally created to support MCP sensitivity diagnostic tests Relates to NOI for Cluster

MSSL Support Data Product: MODE

PEACE Data Products in DAA Support (TBD) MSSL MODE It contains a time history of instrument modes: Time spent in eclipse mode MCP tests Engineering tests Use of the “a”, “aa” and “ab” modes, variations in energy coverage and times when the instrument experienced problems can be included This can be a document or a time series parameter set Was not done for Cluster

MSSL