<simpleType name="sourceTypeEnumType">
  <annotation>
    <documentation>1) impulsive - an energy source of short duration that is repeatable and does not generate noise that interferes with detection. 2) nonimpulsive - an energy source transmitted into the ground for an extended period of time.</documentation>
  </annotation>
  <restriction base="string">
    <enumeration value="impulsive">
      <annotation>
        <documentation>impulsive - impulsive value.</documentation>
      </annotation>
    </enumeration>
    <enumeration value="nonimpulsive">
      <annotation>
        <documentation>nonimpulsive - nonimpulsive value.</documentation>
      </annotation>
    </enumeration>
  </restriction>
</simpleType>