benchmark, date, observer, organization, receiver, receiver_sn, receiver_type, antenna, antenna_sn, dome, height (m), slant height (m), interval, first_observation (s)
 grv1 GraveRm1_USGS, 2002-03-06,  JMS ,  USGS ,  ASHTECH,  LP019992804 ,  Z-XII3 CD00,  ASH701945B_M,  CR619992801,  NONE, 1.3763, 1.4239, 30, 10
 grv1 GraveRm1_USGS, 2002-03-07,  JMS ,  USGS ,  ASHTECH,  LP019992804 ,  Z-XII3 CD00,  ASH701945B_M,  CR619992801,  NONE, 1.3763, 1.4239, 30, 10
 grv1 Grv_1_USGS, 2006-04-20,  JMS ,  USGS ,  ASHTECH,  LP020000801 ,  Z-XII3 CD00,  ASH700936D_M,  CR14333,  NONE, 1.4388, 1.4859, 30, 30
 grv1 Grv_1_USGS, 2006-04-21,  JMS ,  USGS ,  ASHTECH,  LP020000801 ,  Z-XII3 CD00,  ASH700936D_M,  CR14333,  NONE, 1.4388, 1.4859, 30, 30
 grv1 Grv_1_USGS, 2006-04-22,  JMS ,  USGS ,  ASHTECH,  LP020000801 ,  Z-XII3 CD00,  ASH700936D_M,  CR14333,  NONE, 1.4388, 1.4859, 30, 30
 grv1 Grv_1_USGS, 2011-07-08,  JLS ,  USGS ,  ASHTECH,  ZE1200331017 ,  Z-X ZE210,  ASH700936D_M,  CR14330,  NONE, 0.8632, 0.9179, 15, 163245
 grv1 Grv_1_USGS, 2011-07-09,  JLS ,  USGS ,  ASHTECH,  ZE1200331017 ,  Z-X ZE210,  ASH700936D_M,  CR14330,  NONE, 0.8632, 0.9179, 15, 0
 grv1 Grv_1_USGS, 2011-07-10,  JLS ,  USGS ,  ASHTECH,  ZE1200331017 ,  Z-X ZE210,  ASH700936D_M,  CR14330,  NONE, 0.8632, 0.9179, 15, 0
 grv1 Grv_1_USGS, 2011-07-11,  JLS ,  USGS ,  ASHTECH,  ZE1200331017 ,  Z-X ZE210,  ASH700936D_M,  CR14330,  NONE, 0.8632, 0.9179, 15, 0