#-------------------------------------------------------------------------------
# This file defines the IGb20 "core" network, recommended for the alignment of
# global solutions to the IGb0 reference frame. This core network was designed
# to have the best possible global distribution and temporal stability. It is
# composed of 55 clusters of stations (i.e., 55 primary stations each with
# possible substitutes) listed below.
#-------------------------------------------------------------------------------
AREQ SCRZ UNSA
BADG ULAB IRKJ IRKT
BAKE CHUR YELL HOLM
BHR4 BHR1 BAHR YIBL NAMA
CHPI UFPR BRAZ SAVO
CHTI CHAT
CKIS NIUM ASPA FALE
CPVG DAKR DAKA 
CRO1 ABMF LMMF RDSD SCUB
CZTG
DAEJ SUWN TAEJ
DARW KAT1 TOW2 ALIC
DAV1 MAW1
DGAR SEYG SEY1
FAIR WHIT INVK UTQI
GAMB
GLPS GALA RIOP QUI3
GODN GODE ALGO NRC1
GOUG
GUAM GUUG CNMR
GUAT SSIA
HRAO SUTM SUTH SBOK HNUS
IISC HYDE SGOC
ISPA EISL
KIRI NAUR MAJU KWJ1 POHN
KIRU TRO1 TROM NYAL
KOKB HNLC
KRGG KERG
KZN2 ARTU MDVJ MDVO
MAC1 OUS2 MQZG
MAL2 MALI RCMN NURK MBAR
MAS1 LPAL FUNC
MATE NOT1 NOTO M0SE CAGL
MCIL CCJ2 CCJM
MKEA MAUI
MOBS SYDN TIDB TID1 HOB2
NANO ALBH BREW DRAO WILL
NKLG BJCO YKRO
NNOR YAR2 YAR1 PERT MRO1
NRMD NOUM KOUC LAUT TUVA
OHI3 OHI2 OHIG PALM ROTH
POL2 CHUM KIT3 GUAO URUM
REUN VACS ABPO VOIM
RIO2 RIOG PARC FALK
SALU BRFT FORT KOUG KOUR
SANT ANTC CONZ CFAG CORD
SCTB MCM4 DUM1 CAS1
STHL ASCG ASC1
STJ3 STPM STJO HLFX NAIN
THU2 THU1 KELY QAQ1 SCOR
THTG THTI FAA1
CKSV TNML TCMS KMNM SHAO
VESL SYOG
VNDP MONP GOLD PIE1 QUIN
XMIS COCO BAKO CIBG JOG2