benchmark, date, observer, organization, receiver, receiver_sn, receiver_type, antenna, antenna_sn, dome, height (m), slant height (m), interval, first_observation (s)
 lett LETT_USGS, 2011-11-05,  JMS ,  USGS ,  ASHTECH,  ZE120023208 ,  Z-X ZE210,  ASH701945E_M,  CR620022605,  NONE, 0.7381, 0.7959, 15, 0
 lett LETT_USGS, 2011-11-06,  JMS ,  USGS ,  ASHTECH,  ZE120023208 ,  Z-X ZE210,  ASH701945E_M,  CR620022605,  NONE, 0.7381, 0.7959, 15, 0
 lett LETT_USGS, 2011-11-07,  JMS ,  USGS ,  ASHTECH,  ZE120023208 ,  Z-X ZE210,  ASH701945E_M,  CR620022605,  NONE, 0.7381, 0.7959, 15, 0
 lett LETT_USGS, 2012-10-16,  JLS ,  USGS ,  JAVAD,  00619 ,  TRE_G3TH SIGMA3.3.1,  ASH700936D_M,  CR14329,  NONE, 0.8458, 0.9009, 15, 185445
 lett LETT_USGS, 2012-10-17,  JLS ,  USGS ,  JAVAD,  00619 ,  TRE_G3TH SIGMA3.3.1,  ASH700936D_M,  CR14329,  NONE, 0.8458, 0.9009, 15, 0
 lett LETT_USGS, 2012-10-18,  JLS ,  USGS ,  JAVAD,  00619 ,  TRE_G3TH SIGMA3.3.1,  ASH700936D_M,  CR14329,  NONE, 0.8458, 0.9009, 15, 0
 lett LETT_USGS, 2013-05-22,  JMS ,  USGS ,  ASHTECH,  ZE1200526028 ,  Z-X ZE210,  ASH701945E_M,  CR520031622,  NONE, 0.813, 0.8689, 15, 0
 lett LETT_USGS, 2013-05-23,  JMS ,  USGS ,  ASHTECH,  ZE1200526028 ,  Z-X ZE210,  ASH701945E_M,  CR520031622,  NONE, 0.813, 0.8689, 15, 0
 lett LETT_USGS, 2016-08-13,  ELP ,  USGS ,  JAVAD,  01658 ,  TRE_G3TH SIGMA3.5.9,  JAVRINGANT_DM,  00580,  NONE, 0.8069, 0.8629, 15, 0
 lett LETT_USGS, 2016-08-16,  ELP ,  USGS ,  JAVAD,  01660 ,  TRE_G3TH SIGMA3.5.1,  JAVRINGANT_DM,  00580,  NONE, 0.8714, 0.9259, 15, 143945
 lett LETT_USGS, 2017-08-15,  ELP ,  USGS ,  JAVAD,  01337 ,  TRE_G3TH SIGMA3.5.1,  JAVRINGANT_DM,  00585,  NONE, 0.8274, 0.8829, 15, 155915
 lett LETT_USGS, 2017-08-16,  ELP ,  USGS ,  JAVAD,  01337 ,  TRE_G3TH SIGMA3.5.1,  JAVRINGANT_DM,  00585,  NONE, 0.8274, 0.8829, 15, 0
 lett LETT_USGS, 2017-08-17,  ELP ,  USGS ,  JAVAD,  01337 ,  TRE_G3TH SIGMA3.5.1,  JAVRINGANT_DM,  00585,  NONE, 0.8274, 0.8829, 15, 0
 lett LETT_USGS, 2017-08-18,  ELP ,  USGS ,  JAVAD,  01337 ,  TRE_G3TH SIGMA3.5.1,  JAVRINGANT_DM,  00585,  NONE, 0.8274, 0.8829, 15, 0