Draim tetrahedron constellation

The Draim tetrahedron is a configuration of 4 satellites in elliptical orbits providing full Earth coverage at any time. The concept was invented by John E.Draim and explained in (1)

iTetrahedron shape and satellite orbits

Draim tetrahedron depth of satellite coverage

The Constellation Wizard allows to define a Draim tetrahedron constellation:

Constellation period	Orbit period of each satellite in the constellation. This is linked to the Semi-major axis. Changing one will change the other.
Inclination	Inclination for all the satellites in the constellation.
Eccentricity	Eccentricity for all the satellites in the constellation. Usually keep zero for circular orbits
Semi-major axis	Semi-major axis for all the satellites in the constellation. This is linked to the constellation period. Changing one will change the other.
Epoch	Common epoch time for all the constellation satellites

(1) "A Common-Period Four-Satellite Continuous Global Coverage Constellation". John E.Draim. AIAA Journal of Guidance, Control and Dynamics, vol. 10, no. 5, September-October 1987, pp. 492-499.