benchmark, date, observer, organization, receiver, receiver_sn, receiver_type, antenna, antenna_sn, dome, height (m), slant height (m), interval, first_observation (s)
 grat Grate_1985_USGS, 1998-07-24,  JMS ,  USGS ,  ASHTECH,  O4579 ,  Z-XII3 1E95,  ASH700936D_M,  CR14329,  NONE, 1.2884, 1.3368, 30, 15310
 grat Grate_1985_USGS, 1999-07-24,  GDH ,   ,  ASHTECH,  203 ,  Z-XII3 1F50,  ASH700936E_C,  CR16381,  NONE, 1.2055, 1.2548, 30, 15560
 grat Grate_1985_USGS, 1999-07-25,  GDH ,   ,  ASHTECH,  203 ,  Z-XII3 1F50,  ASH700936E_C,  CR16379,  NONE, 1.1133, 1.1637, 30, 15360
 grat Grate_1985_USGS, 2002-07-10,  GDH ,  USGS ,  ASHTECH,  LP03360 ,  Z-XII3 CC00,  ASH700936D_M,  CR14330,  NONE, 1.2147, 1.2639, 30, 153930
 grat Grate_1985_USGS, 2002-07-11,  CHS ,  USGS ,  ASHTECH,  LP019992804 ,  Z-XII3 CD00,  ASH700936D_M,  CR14333,  NONE, 1.2622, 1.3109, 30, 15340
 grat Grate_1985_USGS, 2005-07-20,  GDH ,  USGS ,  ASHTECH,  579 ,  Z-XII3 CD00,  ASH701945B_M,  CR519993706,  NONE, 1.1803, 1.2299, 30, 15540
 grat Grate_1985_USGS, 2005-09-27,  JLS ,  USGS ,  ASHTECH,  ZE1200331018 ,  Z-X ZE21,  ASH701945B_M,  CR619992805,  NONE, 1.1864, 1.236, 30, 162130
 grat Grate_1985_USGS, 2007-07-23,  GDH ,  USGS ,  ASHTECH,  ZE120023204 ,  Z-X ZE21,  ASH700936D_M,  CR14244,  NONE, 1.2288, 1.2778, 30, 172730
 grat Grate_1985_USGS, 2007-07-24,  GDH ,  USGS ,  ASHTECH,  ZE120023204 ,  Z-X ZE21,  ASH700936D_M,  CR14244,  NONE, 0.4492, 0.5199, 30, 173430
 grat Grate_1985_USGS, 2009-07-15,  JLS ,  USGS ,  ASHTECH,  LP020000801 ,  Z-XII 1L001,  ASH701945B_M,  CR619992801,  NONE, 1.1965, 1.2459, 30, 143930
 grat Grate_1985_USGS, 2009-07-16,  JMS ,  USGS ,  ASHTECH,  579 ,  Z-XII 1L001,  ASH700936D_M,  CR14330,  NONE, 1.3046, 1.3529, 30, 153530
 grat Grate_1985_USGS, 2011-08-14,  JLS ,  USGS ,  ASHTECH,  ZE120023204 ,  Z-X ZE210,  ASH700936D_M,  CR14330,  NONE, 1.1813, 1.2309, 15, 141215
 grat Grate_1985_USGS, 2011-08-15,  CHS ,  USGS ,  ASHTECH,  LP019992804 ,  Z-XII 1L001,  ASH700936D_M,  CR14341,  NONE, 1.2481, 1.2969, 15, 153315