benchmark, date, observer, organization, receiver, receiver_sn, receiver_type, antenna, antenna_sn, dome, height (m), slant height (m), interval, first_observation (s)
 grey GREY_USGS, 2003-09-15,  WCH ,  USGS ,  ASHTECH,  LP03175 ,  Z-XII3 CD00,  ASH700936E_C,  CR16376,  NONE, 0.4706, 0.5399, 30, 174830
 grey GREY_USGS, 2003-09-16,  WCH ,  USGS ,  ASHTECH,  LP03175 ,  Z-XII3 CD00,  ASH700936E_C,  CR16376,  NONE, 0.4706, 0.5399, 30, 30
 grey GREY_USGS, 2011-09-20,  SW ,  USGS ,  ASHTECH,  ZE120023208 ,  Z-X ZE210,  ASH701945E_M,  CR620022601,  NONE, 0.7617, 0.8189, 15, 172445
 grey GREY_USGS, 2011-09-21,  SW ,  USGS ,  ASHTECH,  ZE120023208 ,  Z-X ZE210,  ASH701945E_M,  CR620022601,  NONE, 0.7607, 0.8179, 15, 0
 grey GREY_USGS, 2011-09-22,  SAH ,  USGS ,  ASHTECH,  ZE1200526043 ,  Z-X ZE210,  ASH701945B_M,  CR519993706,  NONE, 1.1914, 1.2409, 15, 152715