Computing properties: Gravity

Sensor over relief [m]: Specify the sensor height over relief in meters. MUST NOT be negative.

Units:Choose units you want to use.  If custom units are used, the resulting field is multiplied by the supplied value, which MUST NOT be zero (0.0).

Reference density: If you want to use absolute density for bodies (2700 kg/m3) set the reference density - recommended. The density used for computation is then: DensComputation = DensityBody - RefererenceDensity. If reference density is 0.0 then reference density is ignored, you can use relative densities. Reference density can be also linearly increasing. Then set the density gradient and origin. If all the components of density gradient vector are 0.0, linearly increasing density is ignored. 
Note: The reference density is applied to the bodies itself (not to the whole model volume).

Gradients tensor: Set either constant flight elevation or height over relief where the field is to be computed. Multiply resulting field by supplied value (i.e. displaying purposes, unit conversion...), which MUST NOT be zero (0.0).