G. Bianco, M. Virelli Agenzia Spaziale Italiana, CGS - Matera

V. Luceri e-GEOS S.p.A., CGS - Matera

C. Sciarretta Telespazio S.p.A., CGS - Matera

16th International Workshop on Laser Ranging, Poznan, 13-17 October 2008

TRA

NSL

ATIO

NS

SCA

LE

TX

TY

TZ

North

East

+X

where: Xi, , Yi, Zi : X, Y, Z coordinate of the i-th site of the week ni : number of observations of the i-th site of the week Ntot : total number of observations in the week

A weekly time series of the LAGEOS 1/2 data barycenter has been computed, expressed as coordinates (dX,dY,dZ) in the ITRF reference frame.

1993 2008

1993

2008

ITRF origin

1993

2008

Correlation coefficients scale/X = 0.32 scale/Y = 0.45 scale/Z = 0.06

Data Barycenter

Scale

mm

meters

Correlation coefficient scale/rXY = 0.45

rXY = distance of the data barycenter from the ITRF origin, in the XY plane (equator)

mm

meters

Correlation coefficient scale/r = 0.27

r = distance of the data barycenter from the ITRF origin

• Unbalanced data distribution since 2002

• Possible effect of the longitudinal data distribution on the scale to SLRF2005

• No evidence of the North/South data distribution influence on the scale to SLRF2005

• Further investigations with network simulation to:  assess the correlation scale/data barycenter  check the reliability of scale estimation