Units - Internal

Internally, GM-SYS Profile Modelling stores all distances in kilometers, with the exception of the ECS (external coordinate system) file. The ECS origin is displayed in the units defined by the Scale factor (current units x 1/Scale to get kilometers). For display within GM-SYS Profile Modelling, values are scaled to display in other units.

In GM-SYS Profile Modelling, Z is always positive down; i.e., Z-values are stored as "depth below sea-level". Therefore, locations above sea level are negative.

  • Density values are stored using cgs units, grams per cubic centimeter
  • Susceptibility values are stored using cgs units, which are dimensionless, but differ from µcgs by 1/1,000,000 and from SI by 1/4p
  • Velocity values are stored in meters per second
  • Gravity gradient values are stored in Eötvös units
  • Magnetic gradient values are stored in nanotesla per meter