CVA-CTA-Calculator
Contents:
Overview
This PlugIn calculates a boundary norma and boundary normal velocity according to the
CTA (Constant Thickness Approach) and CVA (Constant Velocity Approach) methods
listed in Haaland et al, Annales Geophysicae, No 2, 2004.
Input data
Required inputs are the four spacecraft positions, the center time and the relative
crossing times for the four spacecrafts. An optional array with crossing half durations
may suypplied - CTA outputs (normal, velocity and thickness) are then returned.
Outputs
Output quantities are:
- CVA_Normal - vector with the boundary unit normal from CVA
- CTA_Normal - vector with the boundary unit normal from CTA (if half thicknesses supplied)
- Vn_Cva - boundary velocity along the CTA_normal
In addition, the normals and velocities (and CTA thickness) is printed to the standard output window.
Bugs/Caveats
Important: Note that the crossing durations are characteristic
half time thicknesses; i.i., the
time [in seconds] it takes for a SC to transverse from the outher edge of the boundary to the centre
of the boundary.
SEH, 13 Jan, 2004