** Next:** INVERSE MAPPING
** Up:** FORWARD MAPPING
** Previous:** From elastic constants to

*P*- and *SV*-wave phase velocities
near the horizontal axis can be obtained
by interchanging *W*_{11} and
*W*_{33} and *c*^{2} and *s*^{2} wherever they occur in equations
(3) through (8). Thus, for *P*-waves the result is

| |
(12) |

where
| |
(13) |

and
| |
(14) |

For *SV*-waves, the expression for the phase velocity near the
horizontal
axis is
| |
(15) |

where
| |
(16) |

and
| |
(17) |

Near the horizontal axis the *SH*-wave phase velocities are

| |
(18) |

where
| |
(19) |

and
| |
(20) |

In the rest of the paper I refer to the elliptical parameters
*W*_{P,x}, *W*_{P,z}, *W*_{P,xnmo},
*W*_{P,znmo}, *W*_{SV,x}, *W*_{SV,z}, *W*_{SV,xnmo}, *W*_{SV,znmo},
*W*_{SH,x}, *W*_{SH,z}, *W*_{SH,xnmo}, and *W*_{SH,znmo} as
*W*_{*}, direct or *NMO* phase velocity squared for *P*-, *SV*-, and
*SH*-waves.

** Next:** INVERSE MAPPING
** Up:** FORWARD MAPPING
** Previous:** From elastic constants to
Stanford Exploration Project

11/17/1997