benchmark, date, observer, organization, receiver, receiver_sn, receiver_type, antenna, antenna_sn, dome, height (m), slant height (m), interval, first_observation (s)
 r502, 2001-09-14,  CHS ,   ,  ASHTECH,  lp020000801 ,  Z-XII3 CD00,  ASH701945B_M,  CR519993702,  NONE, 1.359, 1.4068, 30, 15130
 r502, 2001-09-20,  CWW ,   ,  ASHTECH,  02270 ,  Z-XII3 CC00,  ASH701945B_M,  CR519992603,  NONE, 1.3964, 1.4438, 30, 15340
 r502 R502_1981_NGS, 2005-09-18,  CHS ,  USGS ,  ASHTECH,  ZE1200331006 ,  Z-X ZE21,  ASH700936D_M,  CR14333,  NONE, 1.5003, 1.5469, 30, 152130
 r502 R502_1981_NGS, 2005-09-20,  GDH ,  USGS ,  ASHTECH,  ZE1200331017 ,  Z-X ZE21,  ASH701945B_M,  CR619992801,  NONE, 1.4056, 1.4529, 30, 163230
 r502 R502_1981_NGS, 2010-08-10,  CHS ,  USGS ,  ASHTECH,  ZE1200526043 ,  Z-X ZE210,  ASH701945B_M,  CR619992805,  NONE, 1.4368, 1.4839, 15, 152515
 r502 R502_1981_NGS, 2010-08-11,  CHS ,  USGS ,  ASHTECH,  ZE1200526043 ,  Z-X ZE210,  ASH701945B_M,  CR619992805,  NONE, 0.8079, 0.8638, 15, 0