Determination of crustal deformations based on GPS observing-session duration in Marmara region, Turkey

This paper reports on the estimation of changes of a GPS-based crustal deformation field as function of the observing session duration. This investigation was carried out on the Marmara Continuous GPS Network (Marmara region) by using GPS data collected on a set of 10 stations during the period 2002.50–2005.47 The GPS observations were processed in the ITRF 2005 reference frame using Bernese v5.0 software.Main results indicate that GPS data observation periods of 24 h are significantly more accurate than estimates determined from the short observing session. The squared sum of residuals for the 4-h data set (between 12:00 and 16:00 local time) are larger than the other data sets, probably due to the higher ionospheric effects during this time. Also, the deformation pattern obtained from the results of 8 h or more of the GPS data observations as depends on baseline length approaches to the deformation obtained from the results of 24 h GPS data observations.