## 1 Introduction
[18] first applied InSAR to landslide monitoring by employing the differential InSAR (D-InSAR) technique with ERS-1 SAR images to monitor small displacements of the Saint-Etienne-de-Tinee landslide in southern France, demonstrating a high consistency with ground-based measurements. With the rapid advancement and increasing deployment of SAR satellites over the past few decades, some scholars have also attempted to use multi-orbit InSAR, that is, using both ascending and descending images, or images from different platforms, for landslide monitoring. They have demonstrated that multi-orbit InSAR can offer certain advantages over using a single orbit [19; 20; 21]. For instance, [PERSON] et al. [22] employed multi-platform InSAR observations based on Sentinel-1 and ALOS-2 PALSAR-2 to reveal the complex surface displacements that retrieve a quasi-three-dimensional displacement field for the Nanyu landslide in China. [PERSON] et al. [23] developed a multi-orbit InSAR image fusion technique to enhance the identification of active landslides in alpine valley areas, demonstrating that the fused images significantly improved the spatial visibility, increasing the number of identified landslides by 31.5% and the total area by 50.9% on average, surpassing the capabilities of single-orbit InSAR observations. When searching the Web of Science (WoS) database for articles related to \"InSAR\" and \"landslide\", an explosive increase in the number of publications can be observed since 2018 (Figure 1). This notable surge is likely associated with the proliferation and widespread accessibility of satellite SAR data sources, particularly from missions such as Sentinel-1 (Sentinel-1A and Sentinel-1B, launched in 2014 and 2016, respectively) and SAOCOM (SAOCOM-1A and SAOCOM-1B, launched in 2018 and 2020, respectively). Considering the operational timelines of these satellite SAR constellations, the lag in publication growth may stem from the time required for SAR data accumulation, which is essential for conducting comprehensive time-series analysis. In addition, the pairing of SAR satellites such as Sentinel-1A and Sentinel-1B can significantly improve the revisit frequency, further promoting the adoption of satellite SAR in landslide research. In recent years, InSAR techniques have been widely used in landslide monitoring [24; 25; 26], as well as in landslide susceptibility mapping (LSM) [27; 28; 29], which refers to the likelihood of landslides occurring within a particular area under specific environmental circumstances [30]. This boom not only reflects the growing adoption and advancements of methodology regarding landslide research using InSAR but also highlights the need for systematic reviews of published literature to synthesize and evaluate the expanding corpus of knowledge in this field. While several existing reviews have explored the application of InSAR in landslide studies, they exhibit certain limitations. [PERSON] and [PERSON] [31] investigated the use of InSAR for monitoring surface displacements in the Indian Himalayas, highlighting the potential of InSAR as a critical tool for hazard assessment and mitigation from a regional perspective instead of providing a global overview of its utilization. [PERSON] et al. [32] conducted a comprehensive review of InSAR's scientific contributions to geospatial monitoring across Europe, particularly in conjunction with global navigation satellite systems (GNSSs), emphasizing methodological advancements and diverse geohazard applications, though it lacks an in-depth discussion of InSAR's specific role in landslide studies. Similarly, [PERSON] et al. [33] evaluated the small baseline subset (SBAS) InSAR technique, detailing its algorithms, applications, and challenges in monitoring geophysical phenomena, including ground subsidence, landslides, seismic activity, permafrost degradation, glacier movement,  
Figure 1: The number of published landslide articles within the WoS database. (Software: Origin 2022). and volcanic activity, but without an in-depth focus on landslide studies.