OTTA
40102S009
OTTB
40102S011
OTT1
40102S005
OTT2
40102S007
NB:
acronyms OTT1 and OTT2 are not in DORIS data file (OTTA instead)
JoG OTTA
data should be deleted from 01-JAN-1990 to 31-JAN-1994
IDS OTTA
data should be deleted from 01-JAN-1990 to 31-JAN-1994
JoG OTT2
should not be used. Too few data
NB: OTT2
corresponds to the period 29-MAY-1991 to 31-AUG-1993
JoG OTTB
data should be deleted from 01-JAN-1990 to 11-FEB-1998
Suspect new
oscillator not stabilized
NB: OTTB
data starts in 11-FEB-1998, so this statement does not make sense. It is
probably a typo
IDS OTTB
data should not be used. Too few data
ITRF OTTA,
OTTB, OTT1, OTT2 are not in ITRF2005
Preliminary
computation:
After some
tests, data for Ottawa (OTTA) before 1-FEB-94 should not be used
However,
for this station, several DOMES numbers were given for the same beacon acronym
(OTTA)
Here is how
DOMES were defined
OTT1=OTTA
01-JAN-1990 – 25-APR-1991 = 40102S005
OTTA
26-APR-1991 - 29-MAY-1991 data
should not be used
OTT2=OTTA
29-MAY-1991 – 31-AUG-1993 = 40102S007
OTTA
01-SEP-1993 – 31-JAN-1994 data should not be used
OTTA
01-FEB-1994 – 03-JAN-1998 need to derive coordinates
OTTB
11-JAN-1998 - ... need to derive coordinates
Velocity
from ITRF2005 velocity field (NOAM) gives (in XYZ) : -16.17 -0.96 3.04
Using
recent DORIS weekly solutions (ign07d02) expressed in ITRF2007 and fixing the
velocity to the above ITRF2005 values, we obtain :
2000.0 OTTA
1107623.4487 -4347253.8500 4518738.0433 -16.17 -0.96 3.04
statistics
OTTA XYZ 0.0022 0.0019 0.0021 196
and the
same for OTTB
2000.0 OTTB
1107623.5809 -4347253.9812 4518738.2261 -16.17 -0.96 3.04
statistics
OTTB XYZ 0.0025 0.0019 0.0018 128
We can
verify these values using the geodetic local tie available from SIMB
OTTB
40102S011 OTTA 40102S005 -0.04 0.16 -0.17 0.02
The vector
derived from the proposed DPOD2005 values is :
OTTB -->
OTTA = -0.132 0.131 -0.183
So the Y-
value is quite different. However the formal error of the local tie is 2 cm, so
looking at this specfic station, it could be acceptable.
Recommendation:
Adopt the DORIS-derived values using ITRF2005 velocity from velocity field
2000.0 OTTA
1107623.4487 -4347253.8500 4518738.0433 -16.17 -0.96 3.04
2000.0 OTTB
1107623.5809 -4347253.9812 4518738.2261 -16.17 -0.96 3.04