benchmark, date, observer, organization, receiver, receiver_sn, receiver_type, antenna, antenna_sn, dome, height (m), slant height (m), interval, first_observation (s)
 6fmk, 1999-09-12,  GWB ,  USGS ,  ASHTECH,  O4597 ,  Z-XII3 CC00,  ASH701945.02B,  CR619992801,  NONE, 1.1042, 1.1548, 30, 1590
 6fmk, 1999-09-24,  GWB ,  USGS ,  ASHTECH,  O4597 ,  Z-XII3 CC00,  ASH701945.02B,  CR619992801,  NONE, 1.1478, 1.1978, 30, 40
 6fmk 6FMK_1973_USGS_Elev., 2003-06-22,  WCH ,  USGS ,  ASHTECH,  LP02232 ,  Z-XII3 6J00,  ASH701945B_M,  CR619992801,  NONE, 0.4898, 0.5579, 30, 15610
 6fmk 6FMK_1973_USGS_Elev., 2003-06-23,  WCH ,  USGS ,  ASHTECH,  LP02232 ,  Z-XII3 6J00,  ASH701945B_M,  CR619992801,  NONE, 0.4898, 0.5579, 30, 0
 6fmk, 2003-06-30,  SAH ,  USGS ,  ASHTECH,  LP019992804 ,  Z-XII3 CD00,  ASH701945E_M,  CR620022602,  NONE, 1.0688, 1.1199, 30, 16410