benchmark, date, observer, organization, receiver, receiver_sn, receiver_type, antenna, antenna_sn, dome, height (m), slant height (m), interval, first_observation (s)
 grnb 81.13_1981_USGS, 2000-08-03,  PWS ,  U So Cal / Ariz Stat,  ASHTECH Z-XII3,  188,  CD00,  ASH700936E_C,  365,  NONE, 0.3755, 0.4521, 0, 173930
 grnb 81.13_1981_USGS, 2000-08-04,  PWS ,  U So Cal / Ariz Stat,  ASHTECH Z-XII3,  188,  CD00,  ASH700936E_C,  365,  NONE, 0.3755, 0.4521, 0, 30
 grnb 81.13_1981_USGS, 2011-07-24,  T Kent K Lisowski ,  USGS/Cascades Volcan,  TRIMBLE,  0220264600 ,  5700 1.20,  TRM41249.00,  60267788,  NONE, 0.3366, 0.4171, 15, 30
 grnb 81.13_1981_USGS, 2011-07-25,  T Kent K Lisowski ,  USGS/Cascades Volcan,  TRIMBLE,  0220264600 ,  5700 1.20,  TRM41249.00,  60267788,  NONE, 0.3366, 0.4171, 15, 30