MGS MAG magnetic field


MGS magnetic field is available in two coordinate systems:
  1. MSO (sun-state, ss)
    The ss coordinate system is defined using the instantaneous Mars-Sun vector as the primary reference vector (x direction). The X-axis lies along this vector and is taken to be positive toward the Sun. The Mars velocity vector is the second vector used to define the coordinate system. The negative of the velocity vector is used as a secondary reference vector so that the vector cross product of x and y yields a vector z parallel to the northward (upward) normal of the orbit plane of Mars. This system is sometimes called a Sun-State (SS) coordinate system since its principal vectors are the Sun vector and the Mars state vector.
  2. Areographic (planetocentric, pc)
    The planetocentric coordinate system is body-fixed and rotates with the body as it spins on its axis. The body rotation axis is the primary vector used to define this coordinate system. Z is taken to lie along the rotation axis and be positive in the direction of angular momentum. The X-axis is defined to lie in the equatorial plane of the body, perpendicular to Z, and in the direction of the prime meridian as defined by the IAU. The Y axis completes the right-handed set.