ABSTRACT The ongoing pattern of groundwater induced land subsidence in major valleys and agricultural regions of Iran has been recently documented by several studies (e.g. [1-4]) using C-band Interferometric Synthetic Aperture Radar (InSAR) observations. In this article we present the results of our research in which we evaluated the performance of C-band, L-band and X- band SAR data, using time-series method of small baseline subset (SBAS), to retrieve long time series of ground subsidence in agricultural regions in the country. Two major groundwater basins have been selected for this purpose: (1) Rafsanjan Valley in the Kerman province of central Iran and (2) Tehran Plain (capital of Iran). We also report on our experience using dual- polarimetry (HH/VV) X-band SAR data for Persistent Scatterer (PS) deformation analysis in natural terrains subject to high rate of deformation. 1. Land subsidence in Rafsanjan To investigate land subsidence in Rafsanjan we utilized 3 sets of images, including 12 Envisat ASAR data in a descending track covering March 2004–June 2006, 23 Envisat ASAR data in an ascending track covering June 2004–August 2007, and 10 ALOS PALSAR data in an ascending track covering December 2007–November 2010. The outline of the SAR frames has been illustrated in Fig. 1. We processed all SAR data with small baseline subset (SBAS) approach implemented in StaMPS software (http://homepages.see.leeds.ac.uk/~earahoo/stamps/inde x.html). Figure 1. Geographic location of the Rafsanjan valley in central Iran. Rectangles show the frames of radar sensors used in this study. Figure 2. Mean line-of-sight (LOS) velocity derived from Envisat ascending data. The black square is the reference area. COMPARISON OF X-BAND, L-BAND AND C-BAND RADAR IMAGES FOR MONITORING SUBSIDENCE IN AGRICULTURAL REGIONS Mahdi Motagh (1) , Mahmud Haghshenas Haghighi (1) , Roghaye Shamshiri (2) , Mustapha Esmaeili (3) (1) GFZ German Research Center for Geosciences, Potsdam, Germany. Email: Motagh@gfz-potsdam.de (2) Norwegian University of Science and Technology, Norway. Email: roghayeh.shamshiri@ntnu.no (3) Department of surveying and Geomatics Engineering, University of Tehran, Iran. Email: mostafaesi@gmail.com _____________________________________ Proc. ‘Fringe 2015 Workshop’, Frascati, Italy 23–27 March 2015 (ESA SP-731, May 2015)