<simpleType name="geophysicalMethodEnumType">
  <annotation>
    <documentation>A controlled list of terms identifying supported field geophysical survey methods.</documentation>
  </annotation>
  <restriction base="string">
    <enumeration value="borehole crosshole seismic"/>
    <enumeration value="borehole image log"/>
    <enumeration value="borehole seismic downhole source"/>
    <enumeration value="borehole seismic surface source"/>
    <enumeration value="electrical resistivity tomography (ERT)"/>
    <enumeration value="electromagnetic induction (EMI)"/>
    <enumeration value="frequency domain reflectometry (FDR)"/>
    <enumeration value="gamma-gamma density"/>
    <enumeration value="gamma ray spectrosocpy"/>
    <enumeration value="gravity, absolute"/>
    <enumeration value="gravity, relative"/>
    <enumeration value="ground penetrating radar"/>
    <enumeration value="induced polarization"/>
    <enumeration value="magnetic resonance sounding (MRS)"/>
    <enumeration value="magnetometry"/>
    <enumeration value="magnetotelluric (MT)"/>
    <enumeration value="marine seismic"/>
    <enumeration value="microtremor array measurement (MAM)"/>
    <enumeration value="multichannel analysis of surface waves (MASW)"/>
    <enumeration value="natural gamma radiation"/>
    <enumeration value="neutron logging"/>
    <enumeration value="passive seismic (HVSR)"/>
    <enumeration value="refraction microtremor (ReMi)"/>
    <enumeration value="seismic reflection"/>
    <enumeration value="seismic refraction"/>
    <enumeration value="self-potential"/>
    <enumeration value="spectral analysis of surface waves (SASW)"/>
    <enumeration value="time-domain reflectometry (TDR)"/>
    <enumeration value="transient electromagnetics (TEM)"/>
    <enumeration value="vertical electrical sounding (VES)"/>
    <enumeration value="very low frequency method (VLF)"/>
  </restriction>
</simpleType>