benchmark, date, observer, organization, receiver, receiver_sn, receiver_type, antenna, antenna_sn, dome, height (m), slant height (m), interval, first_observation (s)
 grve GRVE_2006_USGS, 2006-11-16,  JMS ,  USGS ,  ASHTECH Z-X,  ZE120023202,  ZE21,  ASH701945E_M,  CR520031626,  NONE, 1.4852, 1.5319, 30, 174530
 grve GRVE_2006_USGS, 2006-11-17,  JMS ,  USGS ,  ASHTECH Z-X,  ZE1200526043,  ZE21,  ASH701945E_M,  CR520031622,  NONE, 1.5054, 1.5519, 30, 162930
 grve GRVE_2006_USGS, 2008-07-14,  JMS ,  USGS ,  ASHTECH Z-XII,  LP00108.707,  1L00,  ASH701945B_M,  CR519993706,  NONE, 1.463, 1.5099, 30, 153830
 grve GRVE_2006_USGS, 2008-07-15,  JMS ,  USGS ,  ASHTECH Z-XII,  LP020000801,  1L00,  ASH701945B_M,  CR519993706,  NONE, 1.5285, 1.5749, 30, 1640
 grve GRVE_2006_USGS, 2008-07-30,  JMS ,  USGS ,  ASHTECH Z-X,  ZE120023204,  ZE21,  ASH701945B_M,  CR619992805,  NONE, 1.4913, 1.5379, 30, 15550
 grve GRVE_2006_USGS, 2009-08-12,  JMS ,  USGS ,  ASHTECH Z-X,  ZE1200526043,  ZE210A13,  ASH701945E_M,  CR520031626,  NONE, 1.6081, 1.6539, 30, 16140
 grve GRVE_2006_USGS, 2009-08-20,  CHS ,  USGS ,  ASHTECH Z-X,  ZE120023202,  ZE210A13,  ASH701945E_M,  CR620022605,  NONE, 1.3602, 1.4079, 30, 152730
 grve GRVE_2006_USGS, 2010-06-16,  JMS ,  USGS ,  ASHTECH Z-X,  ZE120023208,  ZE210A13,  ASH700936D_M,  CR14341,  NONE, 1.5265, 1.5729, 15, 154145
 grve GRVE_2006_USGS, 2010-06-24,  JMS ,  USGS ,  ASHTECH Z-X,  ZE1200331006,  ZE210A13,  ASH701945E_M,  CR620022605,  NONE, 1.5195, 1.5659, 15, 154045
 grve GRVE_2006_USGS, 2013-04-19,  JMS ,  USGS ,  ASHTECH Z-X,  ZE120023202,  ZE210A13,  ASH700936D_M,  CR14329,  NONE, 0.9122, 0.9659, 15, 0
 grve GRVE_2006_USGS, 2013-04-20,  JMS ,  USGS ,  ASHTECH Z-X,  ZE120023202,  ZE210A13,  ASH700936D_M,  CR14329,  NONE, 0.9122, 0.9659, 15, 0
 grve GRVE_2006_USGS, 2013-04-21,  JMS ,  USGS ,  ASHTECH Z-X,  ZE120023202,  ZE210A13,  ASH700936D_M,  CR14329,  NONE, 0.9122, 0.9659, 15, 0