Drift determination 2013-11-17

With the instruction file urtap-bigtidesww.ins

ins4env urtap-bigtidesww.ins

a drift model has been estimated. There is compelling evidence that the drift underwent a radical change as a consequence of the repair work in February 2011.

First solution: An exponential with fixed decay time plus a box-car&slope

27 R urtap.tse

#21,'BIN',-99999.0,'L:BARO|VAL',0,0,-9 = BARO
BEGIN_HS 01
% ( From 2011 02 24 00 To 2013 05 17 23 ) = SLP2
t #27 EDECAY = EDEC
END
urtap.tse:
TSF EDIT EDECAY
EXP 1.d0 -2.2663D-03  Tref 2011 02 24 00 00 00 00 From 2011 02 24 00 00 00 00
RMSD
END

tsd -n 34000,1,c -E expstart.tse,E o/g090701-130515-1h-lapww.rh01.ts



There is a decrease of the drift rate.
A tail of the initial exponential decay from mid June 2009 (installation) can be seen. Its amplitude was -186.47 nm/s2.
The exponential decay after February 24, 2010, has an estimated amplitude of  95.53 +-0.73 nm/s2 (note the opposite sign!)
The result is still preliminary - expfitbm should be used to also solve for the decay time.