benchmark, date, observer, organization, receiver, receiver_sn, receiver_type, antenna, antenna_sn, dome, height (m), slant height (m), interval, first_observation (s)
 slvz, 1999-09-17,  GWB ,  USGS ,  ASHTECH,  O4597 ,  Z-XII3 CC00,  ASH701945.02B,  CR619992801,  NONE, 1.3611, 1.4088, 30, 152730
 slvz, 1999-09-21,  GWB ,  USGS ,  ASHTECH,  O4597 ,  Z-XII3 CC00,  ASH701945.02B,  CR619992801,  NONE, 1.2591, 1.3078, 30, 1620
 slvz Slvz_stmpd_GE_894+07, 2003-06-20,  FFP ,  USGS ,  ASHTECH,  04600 ,  Z-XII3 CD00,  ASH700936D_M,  CR14244,  NONE, 1.2905, 1.3389, 30, 1690
 slvz Slvz_stmpd_GE_894+07, 2003-06-25,  MCN ,  USGS ,  ASHTECH,  LP00108.707 ,  Z-XII3 CD00,  ASH701945E_M,  CR620022601,  NONE, 1.3561, 1.4039, 30, 185930
 slvz Slvz_stmpd_GE_894+07, 2008-02-26,  JMS ,  USGS ,  ASHTECH,  ZE120023208 ,  Z-X ZE21,  ASH701945E_M,  CR620022605,  NONE, 0.8233, 0.8789, 30, 0
 slvz Slvz_stmpd_GE_894+07, 2008-02-27,  JMS ,  USGS ,  ASHTECH,  ZE120023208 ,  Z-X ZE21,  ASH701945E_M,  CR620022605,  NONE, 0.8233, 0.8789, 30, 0
 slvz Slvz_stmpd_GE_894+07, 2008-02-28,  JMS ,  USGS ,  ASHTECH,  ZE120023208 ,  Z-X ZE21,  ASH701945E_M,  CR620022605,  NONE, 0.8233, 0.8789, 30, 0
 slvz Slvz_stmpd_GE_894+07, 2008-02-29,  JMS ,  USGS ,  ASHTECH,  ZE120023208 ,  Z-X ZE21,  ASH701945E_M,  CR620022605,  NONE, 0.8233, 0.8789, 30, 0
 slvz Slvz_stmpd_GE_894+07, 2008-09-05,  JLS ,  USGS ,  ASHTECH,  ZE1200331006 ,  Z-X ZE21,  ASH700936D_M,  CR14330,  NONE, 1.1509, 1.2009, 30, 1590
 slvz Slvz_stmpd_GE_894+07, 2008-09-07,  JLS ,  USGS ,  ASHTECH,  ZE1200331006 ,  Z-X ZE21,  ASH700936D_M,  CR14330,  NONE, 1.2015, 1.2509, 30, 14615