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Chapter 2 — Background
Section 4 — Coordinate Systems
Figure 2-2. CORS Stations.
FBN and CBN
Federal Base Network stations (FBN) (75 to 125 km spacing) or Cooperative Base Network
(CBN) stations (25 to 30 km spacings) are B order accuracy and make up the HARN
network. These HARN stations have been observed using GPS and have been either used
previously as reference stations in the adjustment of the old conventionally surveyed federal
monuments or they are newly placed monuments. There are about four hundred of these
listed by NGS in Texas.
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GPS User's Manual
2-8
TxDOT 8/2005