Body Properties: Gravity

Set the physical properties used for the gravitational field computation.

Density: specify the density of a body - ro_body in [kg·m^-3]. Gravitational field is computed using the reference density ro_ref , if the reference density is nonzero. The density used for computation is: ro = ro_body-ro_ref  .

Gradient: specify the density gradient components of a body in kg·m^-4. Take into account, that right-handed coordinate system with positive z-axis pointing upward is used (for increasing density with the depth z component of the gradient is negative). The z density gradient component can be computed as follows: gz = (roH0-roH)/(h0-h), where roH0, roH is the density at depth  h0, h respectively.

Origin: Specify an origin for the density gradient computation. In the origin the density equals to the density of a body. The density in point P is computed as follows: ro_P =  ro_body+ r·g, where g is the density gradient and r is the radius vector from point P to the gradient origin.