Salem, hope ur doing well! well im confusing about Rmf,Rf, Rmc; how we can know their values? by laboratory measurements in the surface in a lab? or we must know their exact values in specific depths? cause the resistivity not the same in surface and at 2500m tht has much more T°?

pls some one to clarify this for me? and thks a lottttttt and sorrrrrrrry