benchmark, date, observer, organization, receiver, receiver_sn, receiver_type, antenna, antenna_sn, dome, height (m), slant height (m), interval, first_observation (s)
 hhtt, 1999-09-11,  GDH ,   ,  ASHTECH,  4600 ,  Z-XII3 CC00,  ASH700936D_M,  CR14341,  NONE, 1.2388, 1.2877, 30, 16030
 hhtt, 1999-09-28,  GDH ,   ,  ASHTECH,  4600 ,  Z-XII3 CC00,  ASH700936D_M,  CR14341,  NONE, 1.3338, 1.3818, 30, 15550
 hhtt, 2003-06-17,  Poland ,  USGS/Cascades Volcan,  TRIMBLE,  16325 ,  4000SSI NP,  TRM29659.00,  20693,  NONE, 0.9409, 0, 30, 220
 hhtt, 2003-06-18,  Poland ,  USGS/Cascades Volcan,  TRIMBLE,  16325 ,  4000SSI NP,  TRM29659.00,  20693,  NONE, 0.9409, 0, 30, 30
 hhtt, 2003-06-19,  Poland ,  USGS/Cascades Volcan,  TRIMBLE,  16325 ,  4000SSI NP,  TRM29659.00,  20693,  NONE, 0.9409, 0, 30, 30
 hhtt HHTT_02-KM_1996_CalT, 2008-09-09,  SAH ,  USGS ,  ASHTECH,  579 ,  Z-XII 1L00,  ASH701945E_M,  CR520031626,  NONE, 1.1793, 1.2289, 30, 1630
 hhtt HHTT_02-KM_1996_CalT, 2008-09-10,  JMS ,  USGS ,  ASHTECH,  ZE120023204 ,  Z-X ZE21,  ASH701945E_M,  CR620022605,  NONE, 0.7925, 0.8488, 30, 15320
 hhtt HHTT_02-KM_1996_CalT, 2013-09-05,  JLS ,  USGS ,  JAVAD,  00618 ,  TRE_G3TH SIGMA3.3.1,  ASH701945E_M,  CR620022605,  NONE, 0.7298, 0.7879, 15, 18145
 hhtt HHTT_02-KM_1996_CalT, 2013-09-06,  JLS ,  USGS ,  JAVAD,  00618 ,  TRE_G3TH SIGMA3.3.1,  ASH701945E_M,  CR620022605,  NONE, 0.7298, 0.7879, 15, 0
 hhtt HHTT_02-KM_1996_CalT, 2013-09-07,  JLS ,  USGS ,  JAVAD,  00618 ,  TRE_G3TH SIGMA3.3.1,  ASH701945E_M,  CR620022605,  NONE, 0.7298, 0.7879, 15, 0
 hhtt HHTT_02-KM_1996_CalT, 2013-09-08,  JLS ,  USGS ,  JAVAD,  00618 ,  TRE_G3TH SIGMA3.3.1,  ASH701945E_M,  CR620022605,  NONE, 0.7298, 0.7879, 15, 0