u201d h x h y h z c xx c xy c xz c yx c yy c zz c zx c zy c zz u2061 m x m y m z 4 of course equation 3 is also valid in the induction tool coordinate system so the relationship between the coupling matrices c and c u2033 can be determined from equations 1 3 and 5 to be the induction tool can determine each of the elements of c u2033 from magnetic field measurements coupling matrix element c ij u2033 i j x u2033 y u2033 z u2033 is calculated from where r i t j is the magnetic field measured by the ith receiver in response to the jth transmitter and m j is the magnetic moment of the jth transmitter if each of the transmitters has the same magnetic moment m the coupling matrix can be expressed c u2033 1 m u2061 rx u2033 u2062 tx u2033 rx u2033 u2062 ty u2033 rx u2033 u2062 tz u2033 ry u2033 u2062 tx u2033 ry u2033 u2062 ty u2033 ry u2033 u2062 tz u2033 rz u2033 u2062 tx u2033 rz u2033 u2062 ty u2033 rz u2033 u2062 tz u2033 8 note that due to changes in the formation as a function of depth the coupling constants are also functions of depth the strike angle can be determined directly from the measured signals for example it can be calculated by knowing the strike angle an inverse u03b2 rotation can be.