## 4 Result  
Following the workflow outlined in Figure 5, we obtained the offset field of the study area. Optical displacement fields before and after error elimination are displayed in Figure 6. Due to different imaging periods and conditions, the raw offset fields had serious orbital errors (Figure 6a,c). As Figure 6 shows, feature radiance intensity exhibits a clear difference, leading to a significant lack of consistency. Trend inaccuracies resulting from satellite attitude instability are significant. These errors directly mask a large portion of information related to surface deformation. After error correction, decorrelation noise, orbital errors, and satellite attitude jitter distortions are effectively eliminated, facilitating the retrieval of deformation signals (Figure 6b,d). The 2D offset field contains the deformation signals extracted from two earthquakes, featuring an average displacement of 0.67 m and a maximum displacement of 2.8 m in the E-W direction as well as an average displacement of 0.71 m and a maximum displacement of 2.4 m. The predominant slip was on the NE-SW fault. Notably, in the vicinity of the main shock's epicenter, N-S displacement surpassed the E-W displacement. A right-lateral strike-slip motion during the main shock was indicated by the E-W deformation, which manifested as westward displacement on the main shock's south side and overall eastward displacement to the north. The Mw7.4 earthquake, the main shock, was dominated by the right-lateral strike-slip. Our findings align well with those of previous studies [40; 41], showing good concordance in fault trace details and deformation magnitude. In the study area, numerous GNSS stations are deployed on both sides of the ruptured fault ([[https://www.unavco.org/highlights/2019/ridgecrest.html](https://www.unavco.org/highlights/2019/ridgecrest.html)]([https://www.unavco.org/highlights/2019/ridgecrest.html](https://www.unavco.org/highlights/2019/ridgecrest.html)), accessed on 30 August 2019), which can be used to assess the accuracy of the offset field. GNSS monitoring data separate the deformation signals from the two earthquakes; for example, the GNSS monitoring data in Figure 7 exclusively captured signals from the main shock. However, the offset field obtained from RapidEye contains signals of deformation caused by both earthquakes, such as the time for the master and slave images to cover both earthquakes. Therefore, here, we only compare the GNSS monitoring data following the main shock occurrence with the 2D offset field obtained from RapidEye images. We calculated the standard deviations of the E-W and N-S offset fields in the deformation-free regions, both before and after error correction. The average of these two values was used to characterize the uncertainty of the offset field results. The uncertainties of the GNSS stations were obtained from the literature [42] and are listed in Table 6. The results listed in Table 7 show that in the raw E-W displacement field, the differences between the SPC deformation  
Figure 5: Processing flow chart of RapidEye images. values and GNSS observations at TOWG_49 and SRT reach nearly 2 m. Six GNSS stations showing the SPC deformation values differ at about 1 m from GNSS observations. The magnitude of these differences was approximately one-fifth of the deformation caused by the earthquake. In the raw N-S displacement field, the difference between the SPC deformation value and the GNSS observations at P594_G49 was approximately 1.85 m. Three GNSS stations show SPC deformation values differing about 1 m from the GNSS observations. After error correction, the deformation results showed a remarkable 91.7% improvement in accuracy in the E-W direction and 88.9% improvement in accuracy in the N-S direction. The corrected deformation results exhibited good consistency in magnitude and direction with that of GNSS (Figure 7), with an RMSE of 12 cm in the E-W direction and 11 cm in the N-S direction.