1. Cluster Active Archive 1 Drift Velocity/Electric Field Comparison: CIS, EDI, EFW, FGM Jonathan Kissi-Ameyaw Cluster Active Archive ESTEC

2. Cluster Active Archive 2 Generating graphical products comparing instrument drift velocity and electric field data using CAA software architecture Briefly examine the process of product generation Have a quick look at an example of the output Summary Drift Velocity/Electric Field Comparison: CIS, EDI, EFW, FGM Contents

3. Cluster Active Archive 3 CP_EFW_L3_E3D_INERT E_Vec_xyz_ISR2 E_quality CP_EFW_L3_V3D_INERT v_drift_ISR2 E_quality CP_EFW_L3_P Spacecraft_potential CP_EDI_SPIN V_ed_xyz_gse E_xyz_gse Status CP_CIS-HIA_ONBOARD_MOMENTS velocity_isr2 Drift Velocity/Electric Field Comparison: CIS, EDI, EFW, FGM Datasets CP_PEA_MOMENTS Data_Velocity_GSE CP_FGM_SPIN B_vec_xyz_gse CP_AUX_POSGSE_1M sc_r_xyz_gse sc_v_xyz_gse JP_PMP L_value Mag_Local_time Invar_Lat

4. Cluster Active Archive 4 Using CP_AUX_POSGSE_1M: sc_r_xyz_gse, sc_v_xyz_gse JP_PMP: L_value, Mag_Local_time, Invar_Lat L-Shell, Invariant Latitude and Magnetic Local Time data captured and displayed at top of each product Median averaging of SC information and conversion of position information to Earth Radii Drift Velocity/Electric Field Comparison: CIS, EDI, EFW, FGM Spacecraft Position Information

5. Cluster Active Archive 5 Filter data for Fillvals and NaN’s ‘Nearest neighbour’ time interpolation carried out: Drift Velocity EFW readings interpolated to CIS/EDI time +/- 2 second intervals Electric Field EFW readings interpolated to CIS-E/EDI time +/- 2 second intervals Status Quality visualisation where possible (CIS-HIA, EDI, EFW)  = Lower quality data  = Higher quality data For CIS – Electric Field Calculation of CIS-E by using Cross product of CIS Ion velocity and FGM Spin Magnetic field (/10 3 ) Each product contains a Time Series showing EFW SC Potential over the interval Drift Velocity/Electric Field Comparison: CIS, EDI, EFW, FGM Data Treatment

6. Cluster Active Archive 6 Extreme values For velocities, values of an absolute difference > 30 are excluded For fields, values of an absolute difference > 3 are excluded  = Excluded data Perform Robust Linear Regression Capture and display statistical information Post interpolation/post regression fitting Individually Min/Max values Median values Combined y = [m]x + [b] with +/- error factors Number of Data points used Curve correlation – Robust Standard Deviation (σ) Drift Velocity/Electric Field Comparison: CIS, EDI, EFW, FGM Data Treatment continued…

7. Cluster Active Archive 7 Drift Velocity/Electric Field Comparison: CIS, EDI, EFW, FGM CIS/EFW Graphical Product (Velocity)

8. Cluster Active Archive 8 Drift Velocity/Electric Field Comparison: CIS, EDI, EFW, FGM EDI/EFW Graphical Products (Velocity)

9. Cluster Active Archive 9 Drift Velocity/Electric Field Comparison: CIS, EDI, EFW, FGM EDI/EFW Graphical Product (Field)

10. Cluster Active Archive 10 Drift Velocity/Electric Field Comparison: CIS, EDI, EFW, FGM CIS-E/EFW Graphical Products (Field)

11. Cluster Active Archive 11 The main topics discussed today were: Drift Velocity/Electric Field comparisons over a set time Performed various statistical analyses on the data Generated scatter and time series graphical products illustrating results Drift Velocity/Electric Field Comparison: CIS, EDI, EFW, FGM Summary

12. Cluster Active Archive 12 Questions Drift Velocity/Electric Field Comparison: CIS, EDI, EFW, FGM Thank you

13. Cluster Active Archive 13 Resolve scaling issues PEACE – EFW comparison to follow Drift Velocity/Electric Field Comparison: CIS, EDI, EFW, FGM Future Tasks

14. Cluster Active Archive 14 New graphical products showing original comparison plots next to time series for each vector Each time series shows drift velocity/electric field readings pre- interpolation and pre-regression Drift Velocity/Electric Field Comparison: CIS, EDI, EFW, FGM Recent Developments/Additions

15. Cluster Active Archive 15 Drift Velocity/Electric Field Comparison using CAA Software Background 1)Background info – data used CIS-HIA, EDI – Field/velocity, EFW – field/velocity, SC potential, JSOC PMP, AUX POSGSE, FGM Spin 2) Data treatment Fillvall/NaN removal Time interpolation – 2 second intervals to WHISPER Extreme values: for velocities, values of an absolute difference greater > 50 are excluded Extreme values: for fields, values of an absolute difference greater than 20 are excluded Linear regression Robust fitting Variable capture status quality visualisation (EFW/EDI) Calculation of CIS-Electric field by using Cross product of CIS Ion vel and FGM Spin Mag field (/10e^3) Orbit information capture and display: Capture of L-Shell, Invariant Latitude and Magnetic Local Time info Averaging of SC position info to Earth Radii EFW SC potential time series for each plot interval (non-interpolated) 3)Recent developments – additions to comparisons Each plot has sister plot containing time series for each of the 3 vectors. Each time series shows non- interpolated data. Non-interpolated data time series for each interval 4) Summary Scaling issues need resolving PEACE – EFW comparison to be completed