for geodetic measurements, they drill a hole down to bedrock, and run a pipe down to anchor the antenna to the bedrock.
"All holes shall be drilled straight enough so that PVC casing can be installed in the top 15.5 ft of each hole, and that the steel pipe can be freely lowered, not forced, for its entire 35 ft length."
http://kb.unavco.org/kb/article/deep-drilled-braced-monument-overview-300.html http://www.scign.org/arch/sdb_monument.htm Google for Ken Hudnutt's or Frank Webb's papers or a 3m tall monument for a CORS station http://www.mwrtk.net/support_docs/corsinstallprocedures.pdf _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.