Ionospheric Multi-Spacecraft Analysis Tools : : Approaches for Deriving Ionospheric Parameters.

• Superior document: ISSI Scientific Report Series ; v.17
• Author: Dunlop, Malcolm Wray.
• TeilnehmendeR: Lühr, Hermann.
• Place / Publishing House: Cham : : Springer International Publishing AG,, 2019.; ©2020.
• Year of Publication: 2019
• Edition: 1st ed.
• Language: English
• Series: ISSI Scientific Report Series
• Physical Description: 1 online resource (295 pages)

Table of Contents

Intro -- Dedication -- Preface -- Contents -- 1 Introduction -- 2 Introduction to Spherical Elementary Current Systems -- 2.1 Introduction -- 2.2 Short Review of Ionospheric Electrodynamics -- 2.3 Elementary Current Systems -- 2.4 Current and Magnetic Field -- 2.5 Coordinate Transformations -- 2.6 Vector Field Analysis with SECS -- 2.7 Analysis of Ground Magnetic Measurements -- 2.7.1 Separation into Internal and External Parts -- 2.8 Analysis of Satellite Magnetic Measurements -- 2.9 1D SECS -- 2.10 Some Practical Considerations -- 2.10.1 Grid and Boundary Effects -- 2.10.2 Singularities -- 2.10.3 Inversion Regularization -- 2.10.4 Tilted Field Lines -- 2.10.5 Equivalent Current as a Proxy for FAC -- 2.11 How SECS Have Been Used -- References -- 3 Spherical Elementary Current Systems Applied to Swarm Data -- 3.1 Introduction -- 3.2 The Swarm/SECS Analysis Method -- 3.2.1 Current from Magnetic Field Analysis -- 3.2.2 Fitting the Electric Field with CF SECS -- 3.2.3 Conductances from Ohm's Law -- 3.3 Tests with Synthetic Data -- 3.4 Examples of Event Studies -- 3.5 Statistical Studies -- 3.5.1 Swarm-MIRACLE Comparisons -- 3.5.2 Global Current Systems with the Swarm/SECS Method -- 3.6 Conclusions, Discussion, and Future -- References -- 4 Local Least Squares Analysis of Auroral Currents -- 4.1 Introduction -- 4.2 Methodology of Multi-spacecraft Array Techniques -- 4.2.1 General Linear Least Squares -- 4.2.2 Local LS Estimators of Spatial Gradients -- 4.2.3 Local LS Estimators of Electric Currents -- 4.2.4 Related Local Estimators of Gradients and Currents -- 4.2.5 Errors and Limitations -- 4.3 Multi-spacecraft Array Techniques in Practice -- 4.3.1 Implementation of Planar Multi-point Array Estimators -- 4.3.2 Application to Swarm Auroral Crossings -- 4.4 Single-Spacecraft Multi-scale Analysis -- 4.4.1 MVA Applied to Auroral Current Sheets.

4.4.2 Multi-scale Field-Aligned Current Analyzer -- 4.4.3 Application of MS-MVA to Swarm Auroral Crossings -- 4.5 Summary -- References -- 5 Multi-spacecraft Current Estimates at Swarm -- 5.1 Introduction -- 5.2 Basic Application of the Curlometer -- 5.2.1 Four-Spacecraft Technique: Quality Factor and Limitations -- 5.2.2 Cluster Lessons: Implementation, Scale Size and Stationarity -- 5.2.3 Key Regions Covered by Related Methodology -- 5.3 Use of Cluster and THEMIS for in Situ Ring Current Surveys -- 5.3.1 Application of Cluster Crossings to Survey the Ring Current -- 5.3.2 Use of the Magnetic Rotation Analysis (MRA) Method for Field Curvature Analysis -- 5.3.3 Use of THEMIS Three-Spacecraft Configurations to Sample the Ring Current -- 5.3.4 Future Use of MMS and Swarm: Small Separations -- 5.4 Multi-spacecraft Analysis for Swarm: FACs -- 5.4.1 Method: Application of the Curlometer to Stationary Signals -- 5.4.2 Use of Special Configurations: 2-, 3-, 4-, 5-Point Analysis -- 5.4.3 Use of the Extended 'Curlometer' with Swarm Close Configurations: 3-D Current Density -- 5.4.4 Current Sheet Orientation Implied by 2-Spacecraft Correlations -- 5.5 Swarm-Cluster Coordination: FAC Scaling and Coherence -- 5.5.1 Conjunction Characteristics -- 5.5.2 Analysis of Common FAC Signatures -- 5.5.3 Other Events -- 5.6 Conclusions -- References -- 6 Applying the Dual-Spacecraft Approach to the Swarm Constellation for Deriving Radial Current Density -- 6.1 Introduction -- 6.2 Current Estimates from Satellites -- 6.2.1 Single-Satellite Field-Aligned Current Estimate -- 6.2.2 Multi-satellite Current Estimates -- 6.3 The Swarm Dual-SC Current Estimate Approach -- 6.4 Examples of Swarm FAC Estimates -- 6.5 Assessing the Uncertainties of FAC Estimates -- 6.6 Summary and Conclusions -- References -- 7 Science Data Products for AMPERE -- 7.1 Introduction.

7.2 Magnetic Fields and Currents on Spherical Surfaces -- 7.3 Spherical Harmonic Basis Functions -- 7.4 Basis Functions and Data Fitting -- 7.5 Practical Considerations -- 7.6 Estimating Uncertainties -- 7.7 Spherical Elementary Currents and Iridium Data -- 7.8 AMPERE and Other Data Sets -- 7.9 Conclusion -- References -- 8 ESA Field-Aligned Currents-Methodology Inter-comparison Exercise -- 8.1 Introduction -- 8.2 The FAC-MICE Test Dataset -- 8.3 The Active Participants to FAC-MICE -- 8.4 FAC-MICE Comparison Results -- 8.4.1 Comparison for the 'High Correlation' Events -- 8.4.2 Comparison for the 'Low Correlation' Events -- 8.5 FAC-MICE Comparison Summary -- 8.6 FAC-MICE Round Table Discussion and Way Forward -- References -- 9 Spherical Cap Harmonic Analysis Techniques for Mapping High-Latitude Ionospheric Plasma Flow-Application to the Swarm Satellite Mission -- 9.1 Introduction -- 9.2 Theory -- 9.2.1 Spherical Cap Geometry -- 9.2.2 Mapping Electrostatic Potential and Ion Flow by Series Expansion -- 9.2.3 Associated Legendre Functions -- 9.2.4 Boundary Conditions and Basis Functions -- 9.2.5 Non-integer Degree -- 9.3 Practical Example of Mapping Ionospheric Plasma Flow Using SHA and SCHA Approaches -- 9.4 Application of SCHA for Mapping Ionospheric Plasma Flow Based on Swarm Satellite Ion Drift Measurements -- 9.5 Summary -- References -- 10 Recent Progress on Inverse and Data Assimilation Procedure for High-Latitude Ionospheric Electrodynamics -- 10.1 Introduction -- 10.2 Method Overview -- 10.2.1 Representation of Electrodynamic State Variables Using Scalar and Vector Polar-Cap Spherical Harmonic Basis Functions -- 10.2.2 Bayesian State Estimation for Gaussian Processes -- 10.2.3 Nonstationary Covariance Modeling -- 10.3 Analysis of Electrostatic Potential and Electric Fields.

10.4 Analysis of Toroidal Magnetic Potential and Field-Aligned Currents -- 10.5 Dual Optimization Approach -- 10.6 Summary -- References -- 11 Estimating Currents and Electric Fields at Low Latitudes from Satellite Magnetic Measurements -- 11.1 Introduction -- 11.2 Satellite Data Preprocessing -- 11.3 Removing the Sq Field -- 11.4 Estimating EEJ Flow with Line Currents -- 11.5 Estimating Low-Latitude Electric Fields -- 11.5.1 Ionospheric Electrostatic Modeling -- 11.5.2 Estimating the Electric Field -- 11.6 Conclusion -- References -- 12 Models of the Main Geomagnetic Field Based on Multi-satellite Magnetic Data and Gradients-Techniques and Latest Results from the Swarm Mission -- 12.1 Introduction -- 12.2 Fundamentals of Main Field Modelling -- 12.2.1 Calibration of Vector Magnetic Field Measurements -- 12.2.2 Selection of Magnetic Field Data for Main Field Modelling -- 12.2.3 Potential Field Modelling -- 12.2.4 Representation of the Field Due to Internal Sources -- 12.2.5 Representation of the Field Due to External Sources -- 12.2.6 Using Data in the Magnetometer Frame: Co-estimation of Magnetometer Attitude -- 12.2.7 Model Estimation: Solution of the Inverse Problem -- 12.3 Use of Field Gradients and Multi-satellite Data in Main Field Modelling -- 12.3.1 Estimates of Field Gradients: Approximation by Along-Track and Across Track Differences -- 12.3.2 Information Content of Field Gradient Estimates -- 12.3.3 Examples of Field Gradient Data and Their Interpretation -- 12.3.4 Simultaneous Inversion of Data from Multiple Satellites -- 12.4 The Internal Field as Seen by the Swarm Multi-satellite Mission -- 12.4.1 The Core Field -- 12.4.2 The Lithospheric Field -- 12.5 Limitations of Present Main Field Models -- 12.6 Concluding Remarks -- References -- Index.