## 1 Introduction  
Interferometric Synthetic Aperture Radar (InSAR) is a proven remote sensing technique that uses the phase information of SAR images to measure ground surface movements. However, the conventional InSAR method is limited by the so-called temporal and geometrical decorrelation as well as by atmospheric artifacts [1]. Over the years, new advanced InSAR techniques have been proposed to improve the precision of deformation measurement by the joint analysis of a set of SAR images [2; 3], for example, Permanent Scatterer InSAR (PS-InSAR(tm))--use of time series SAR images to detect coherent radar signals over a sequence of interferograms [4; 5]; Small Baseline Subset (SBAS)--use of all available SAR images with small baselines to achieve a high degree of spatial coverage of distributed scatters [6]; Persistent Scatterer Pairs (PSP)--works with pairs of points to identify and analyze persistent scatterer [7]; Quasi Persistent Scatterers (QPS)--utilizes partially coherent targets to increase the spatial density of the observations [8]; Stable Points Network (SPN), which has three key features (i.e., pixel selection, use of multi-master images and modeling capability) and less sensitive to geometric decorrelation [9]; SqueeSAR(tm)--a second generation of PS-InSAR(tm) which combines both the persistent and distributed scatterers [10]; Stanford Method for Persistent Scatterers (StaMPS)--similar to PS-InSAR, but the PS points are defined as the scatters with stable phase characters [11]; Temporarily Coherent Point InSAR (TCPInSAR)--detecting the ground deformation rate and solving the phase ambiguities without phase unwrapping [12]; and Intermittent SBAS (ISBAS)--an extension of SBAS-InSAR that use the pixels which are intermittently coherent in addition to those consistently stable over time [13], etc. These methods have been widely used to measure human- and naturally induced ground deformation, such as earthquake deformation [14; 15], mining subsidence [16; 17], volcano deformation [18; 19], landslides [20; 21] and glacier movement [22; 23]. Additionally, several studies pertaining to gas/oil extraction-induced and CO\({}_{2}\)/water injection-induced surface deformation have been carried out [24; 25; 26; 27; 28]. In particular, the extraction of ground water, oil and gas from underground reservoirs, and the injection of waste-water would induce deformation in reservoirs by changing the reservoir pressure and consequently generate measurable surface deformations in the form of subsidence or uplift [29]. The excessive surface deformation can cause damage to engineering structures and other infrastructure, such as railroads, roads, buildings, and oil and gas pipelines [30; 31]. Thus, identifying the signs of impending land deformation is important in correcting the potential problems before associated accidents/incidents occur [32]. As one of the largest oilfields in China, the Karamay oilfield has large amount of heavy and ultra-heavy oil deposits [33]. After several years of oil field development, a subsurface water injection project was initiated in 1985 to increase the oil production [34]. Despite the Karamay oilfield being in production since 1897 [35], due to the lack of ground measurement data, few studies have been conducted related to the land deformation in this area. [PERSON] et al. [36] first applied the InSAR technique with Advanced Land Observing Satellite (ALOS) Phased Array L-band Synthetic Aperture Radar (PALSAR) images acquired between October 2006 and December 2010 for investigating land-surface displacement in the Karamay oil field, and they detected a significant land uplift area located around the Hei103 well region and concluded that the land uplift may have been caused by subsurface water injection. However, the agreement of the results obtained by different microwave bands of SAR has not yet been achieved. To further understand land-surface deformation in the Karamay oilfield, this paper will make use of three InSAR methods.