triangular elements used
        for 3-D field calculations. </li>
    </ul>
    <h2>Group III: Field Computations:</h2>
    <ul style="font-family: monospace;">
      <li>&nbsp; <a href="field.htm">FIELD</a>&nbsp;&nbsp;&nbsp;&nbsp;
        Computes fields on a vertical array over a specified range and
        for a series of source depths. Individual phones in the array
        may be displaced from the vertical. Range dependence is handled
        by either adiabatic or one-way coupled mode theory.</li>
 