GPS – Global Positioning SystemSpace segment

Control segment

user segment

32 satellites

World wide monitor and control stations

GPS station

Survey GPS Station

Permanent GPS Station

The Transmitted Signal

Carrier waves

PRN code (Satellite ID)

Navigation message

(TOT, satellite position and health)

Data Processing

Your location is:37o 23.323’ N

122o 02.162’ W

Data processing

Absolute positioning Relative positioning Phase observable Estimation and elimination

of measurement biases.

Measurement Biases

Time series and velocity field

north

east

up

WGS84 Reference Frame(World Geodetic System)

ITRF datum(International Terrestrial Reference Frame)

Translation and Rotation

1-D elastic dislocation modelSavage & Burford (1973)

)arctan(1

)( 01 D

xVVxV

V(x)

V0

D

Peri & Wdowinski 2001

V0 = 5 mm/yr

Wdowinski et al. 2004 13 permanent GPS sites were

measured from 1996 – 2002.

Reference frame: Sinai subplate

All

3.7 mm/y

North

4.2 mm/yr

South

2.9 mm/yr

Measuring co-seismic deformationInsight into the 2004 Sumatra–Andaman earthquake

from GPS measurements in southeast AsiaC. Vigny et al. 2005

Earth Quake modeling

Post seismic deformation