HELA
30606S002
HELB
30606S003
HEMB
30606S004
JoG HELB
data to be deleted from 01-FEB-2000 to 31-JUL-2002
Antenna
movement
IDS HELB
data to be deleted from 01-FEB-2000 to 31-JUL-2002
DM#199
HELA Jan 1990 to April 1997 antenna should be rather stable. Corrosion occurs
after April 1997 and before July 2002.
Estimated
tilt is N = 50-60 mm (July 2002)
On July 31,
2002 antenna is put back to initial position
NZ HELB larger
POD residuals
PW it may
be wise to add a break on 31-JUL-2002 due to the large data gap. It could be a
way to check the geodetic local tie
Preliminary
computations:
Position in
ITRF2005 are
HELB 2000.0
6104823.154 -605830.893 -1740720.111 8.78 22.75 18.65
Position
computed from DORIS data, using fixed velocity is
2000.0 HELB
6104823.1519 -605830.8888 -1740720.1019 8.78 22.75 18.65
statistics
HELB XYZ 0.0038 0.0051 0.0029 55
The
difference is quite small, in XYZ/mm -2 +5 +9
It is
possible that the larger POD residuals come from the 2000-2002 (data to be
deleted)? To be confirmed by Nikita.
In DORIS
solution (tf_070515a) X/VX, position before break is
HELB 2000.0
6104823.155 -605830.897 -1740720.100 14.60 18.42 17.29
Position
after break is
HEL1 2000.0
6104823.130 -605830.907 -1740720.101 14.60 18.42 17.29
So there
may be a small difference in X (25mm), but not in Y (10) and Z (1)
In more
recent DORIS solution, position after the break (fixing the velocity to
ITRF2005) (ign07d02) is
2000.0 HEL1
6104823.1438 -605830.9010 -1740720.1185 8.78 22.75 18.65
statistics
HEL1 XYZ 0.0023 0.0037 0.0025 33
and for
HELB
2000.0 HELB
6104823.1510 -605830.8881 -1740720.1094 8.78 22.75 18.65
statistics
HELB XYZ 0.0033 0.0055 0.0028 55
so it is in
good agreement with ITRF2005
Recommendation: