benchmark, date, observer, organization, receiver, receiver_sn, receiver_type, antenna, antenna_sn, dome, height (m), slant height (m), interval, first_observation (s)
 i021 I021_stamped_X90_1931, 1995-04-13,  -Unknown- ,  CALIF DEPT TRANSPORT,  TRIMBLE 4000,  1504,  SSE,  TRM14532.00,  SN_UNKNOWN,  NONE, 2.215, 0, 15, 153645
 i021 I021_stamped_X90_1931, 1995-04-17,  -Unknown- ,  CALIF DEPT TRANSPORT,  TRIMBLE 4000,  1504,  SSE,  TRM14532.00,  SN_UNKNOWN,  NONE, 2.215, 0, 15, 192015
 i021 I021_stamped_X90_1931, 2003-04-28,  SJB ,  SCRIPPS INSTITUTION ,  ASHTECH Z-XII3,  319,  CC00,  ASH700936A_M,  756,  NONE, 0.6452, 0, 30, 152730
 i021 I021_stamped_X90_193, 2010-04-09,  CHS ,  USGS ,  ASHTECH,  ZE1200526028 ,  Z-X ZE210,  ASH701945E_M,  CR520031615,  NONE, 1.2278, 1.2769, 15, 15815
 i021 I021_stamped_X90_193, 2010-04-12,  JMS ,  USGS ,  ASHTECH,  ZE120023208 ,  Z-X ZE210,  ASH701945B_M,  CR519993702,  NONE, 1.1266, 1.1769, 15, 154545