## 1 Introduction  
The Weihe Basin is an intracontinental basin characterized by shear tensile deformation and strong tectonic activity [1]. The fault's depression pattern has been formed since the Eocene under the influence of regional tectonic horizontal extension and vertical force generated by deep material movement. Quaternary active normal faults are well-developed in the Weihe Basin and divided it into multiple fault blocks [2]. The fault structures are dominated by deep and large fault zones in the near EW direction, as well as some secondary NW and NE directions, which jointly control the structural pattern and earthquake-breeding of the Weihe Basin [3]. Among them, the Weihe Fault showsthe most significant segmentation to the basin, with 68% of earthquakes above magnitude 4 and about 70% of earthquakes above magnitude 5 since 1177 AD [4]. In particular, the M8.0 earthquake in Huaxian County, Shaanxi Province on 23 January 1556, is the deadliest earthquake event in China's history, causing over 830,000 casualties and huge property losses [5]. The Moho interface uplifted abruptly relative to the Ordos block and high-speed materials from the upper mantle intruded into the lower crust, providing deep structural conditions for moderately strong earthquakes above [6]. However, it has been quiescent for more than 300 years with only a few moderate and small earthquakes distributed unevenly. Therefore, the Weihe Fault has always attracted attention. Crustal deformation is the direct manifestation of deeper fault activity and therefore plays an important role in understanding the current tectonic deformation pattern and in assessing regional seismic risk. Global navigation satellite system (GNSS) observations are commonly used in the monitoring of the crustal deformation of the Weihe Basin and Fault. The three-dimensional slip rate of the main faults in the Weihe Basin was analyzed through processing GNSS data, combined with the particle swarm algorithm and theoretical dislocation model [7]. The next year, a finite element dynamic model of the Weihe Basin was established to study the characteristics of the regional crustal stress field based on high-precision GNSS monitoring data, and the internal relationship between the Weihe Basin tectonic stress field, and local ground fissures was analyzed [8]. Three-dimensional crustal deformation was derived from GNSS observations before and after the Wenchuan earthquake, and found that the obvious deformation of the Weihe Basin and Fault was caused by strong earthquakes [9]. The tectonic stress and activity characteristics of the faults were inverted by using GNSS, and the genetic mechanism of the earthquakes and ground fissure disasters were subsequently analyzed in the Weihe Basin [10]. The regional vertical motion velocity field was obtained through the dynamic adjustment method constrained by the GNSS vertical motion rate, and the dip-slip rate and locking depth of the main faults were inverted in the Weihe Basin [11]. The Weihe Basin was mainly dominated by extensional movement through GNSS observations, and the differences between the current crustal movement and strain of the Weihe basin and surrounding blocks were analyzed [12]. The maximum shear strain rate at the western end of the Weihe basin appeared in the cycle of 2015-2017, and showed a north-south rotation [13]. As an advanced space observation technology, interferometric synthetic aperture radar (InSAR) has been employed to map the ground deformation of the Weihe Fault. The land subsidence and ground fissure hazards over the Weihe Basin were investigated from InSAR and other technologies, and indicated that the spatial pattern of these hazards was controlled by active faults in the basin, including the Weihe Fault [14]. About 1 mm/yr ground deformation of the Weihe Fault was detected through processing 32 European Space Agency(ESA) Envisat ASAR images from the descending track 161 orbit between 2003 and 2010 [15].