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
