Marion Island

 

MARA 30313S001

MARB 30313S002

MATB 30313S003

 

JoG MARB data to be deleted 01-JAN-2004 to 15-AUG-2004 (end)

Antenna movement

 

IDS MARB break on 01-JAN-2003

 

IDS MARB data to be deleted from 01-JUL-2004 to 15-AUG-2004

 

IDS MATB data to be deleted from 11-APR-2006 to 30-APR-2006

 

ITRF MARB break on 01-JAN-2003

 

DM#453 MATB antenna problem detected. Antenna was found broken near the base on 14-APR-2006

Detected offset is dN=-78 mm, dE = +13 mm, dU = -7 mm

 

DM#479 MATB offsets

Start End

21-08-2004 12-04-2006* OK and centred

13-04-2006* 28-04-2006 Broken, skew (8 cm towards ESE)

29-04-2006 07-11-2006 Repaired, slightly skew (1 cm towards NW)

09-11-2006 current New antenna, centred

 

PW MATB delete data from 01-JAN-2006 to 29-APR-2006

Antenna movement

 

We need to verify if the position after and before the data gap are the same (01-JAN-06 to 29-APR-2006)

 

In ITRF2005 MATB is

 

2000.0 MATB 3448405.7441 2680356.3825 -4632640.5719 -3.77 4.67 0.60

 

Before the break, usng DORIS weekly solutions (ign07d02) using fixed ITRF2005 we get :

 

2000.0 MATB 3448405.7523 2680356.3807 -4632640.5628 -3.77 4.67 0.60

statistics MATB XYZ 0.0024 0.0021 0.0015 67

 

so this is very close to ITRF2005 solution

 

Using data after the data gap, we obtain :

 

2000.0 MAT1 3448405.7603 2680356.3718 -4632640.5680 -3.77 4.67 0.60

statistics MAT1 XYZ 0.0017 0.0018 0.0013 91

 

this is also compatible with ITRF2005. We donÕt need to add a second solution (position/velocity) for MATB after APR-2006. However when combining weekly solution, it is suggested that ACs introduce a break in their time series in order to stay on the safe side.

 

Recommendation:

 

MARB break on 01-JAN-2003

MARB data to be deleted from 01-JUL-2004 to 15-AUG-2004

MATB delete data from 01-JAN-2006 to 14-APR-2006

MATB break on 13-APR-2006, but use identical coordinates (from ITRF2005) before and after the data gap for DPOD2005.