International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B7, 2012 
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia 
MAGNET and Campaign Stations (1999) 
28*00"E 
290'0E 
100 
  
GPS network after 1999 Izmit 
  
Kilometers 
Mosaic image is taken from 
Legend 
Figure 1. MAGNET and campaign sites after 1999 izmit Earthquake red rectangle shows the ERS image boundary 
accurate delay model of troposphere with 12 minutes.(Dach, 
Hugentobler, & Walser, 2009) For SAR analysis ROI PAC 
software is used.(Rosen, Hensley, & Peltzer, 2004). 
GPS data for 17 September 1999 processed by using 
BERNESE software with 12 minutes interval for 
tropospheric delay. Every model and mapping function 
combinations used during processing. The main reason for 
this process is to produce a data set for deciding for which 
delay model will be used. A graph produced for 1 hour 
interval to see the changes, with data which Wet Neill 
mapping function is used. As shown graph (Figure.2) change 
in the values of different models are same and the values are 
close to each other except Hopfield Model. Hopfield delay 
values are less then the other models. 
BERNESE processing of GPS data from Marmara Region 
shows us the variation in tropospheric delays which were 
considered as not significant for Turkey’s atmosphere. 1 hour 
24 
interval for tropospheric correction at zenith for “TUBI” 
station, IGS station which is located on Gebze, at 12 August 
1999 changes between 10cm and 25 cm, the biggest 
difference is 14 cm in one hour from 16:00-17:00 (GMT). By 
using mapping functions we can easily calculate the amount 
of delay for incident angle of SAR image. According to 
Ziyadin Cakir and friends (2003) the tropospheric effects 
mentioned in 16 September and 17 September ERS tandem 
image pairs. This troposphere error causes errors up 14cm 
(range change). Processing the GPS data which is obtained 
from TUBITAK Marmara Research Center for the imaging 
days, with 12 minutes interval of tropospheric delay 
estimation for 23°(icident angle of ERS image) by mapping 
function (wet Neill Model andNeill Mapping Function) the 
mentioned region in Cakir et al. 2003 analyzed for 
tropospheric effects. Two main interpolation method is used, 
Kriging and Inverse Distance interpolation. For both 
techniques the delay differences between tandem days is 14- 
20 cm interval (Figure.3). So research findings are