# Error Sources of Interferometric Synthetic Aperture Radar Satellites
## 1 Introduction
In the evolution of InSAR research, pivotal work from [PERSON] and [PERSON] [29], [PERSON] and [PERSON] [30], [PERSON] and [PERSON] [32], and [PERSON] [28] have significantly contributed to our understanding of error sources. Beyond the references cited, there are numerous other papers that discuss InSAR phase errors and/or decorrelations (e.g., [35; 36; 37; 38; 39]). However, these works often only focus on specific error sources (e.g., tropospheric delay or decorrelations). Moreover, the intricate mathematical formulations found in many existing studies pose challenges for novices seeking comprehension. Despite the wealth of prior research on InSAR error sources, there remains a lack of a clear and easily digestible categorization for all error sources. Addressing this gap and building upon the foundational work of [PERSON] and [PERSON] [30], we classified errors into two primary categories: intrinsic height errors (Section 2.1) and location-induced errors (Section 2.2), predicated on their association with InSAR estimation or imaging location. Additionally, we introduced a new categorization within intrinsic height errors, further dividing them into systematic errors (Section 3) and random errors (Section 4) based on their manifestation under coherent conditions. The organizational structure for each error source is visually represented in Figure 1. This innovative categorization aims to furnish a comprehensive and accessible framework for comprehending InSAR error sources. This paper retains essential equations for a fundamental understanding and provides a comparative analysis of error sources across different radar bands. Our aim is to offer the best entry point for novices seeking to grasp InSAR error sources without the unnecessary complexity found in previous literature. The paper focuses on the emergence of error sources, simplifying concepts for beginners, while preserving essential equations needed for estimation. Additionally, it provides a comprehensive picture of all error sources, comparing different radar bands to illustrate how wavelengths alter the effect of each error origin. This makes our paper the ideal starting point for novices to learn about InSAR. A profound comprehension of error sources is imperative not only for understanding the inherent limitations and potential inaccuracies in InSAR-derived products but also for actively enhancing study outcomes' accuracy and reliability. Notably, research [40] has showcased significant variations in Digital Elevation Models (DEMs) resulting from  
Figure 1: The structure of the error sources with their respective sections in this article. equivalent InSAR workflows over the same area of interest. Consequently, users of InSAR data products must grasp these error sources to optimize their workflows effectively. The intricate InSAR error budget, spanning the entire imaging system, often challenges users in identifying causes of poor-quality outputs. A thorough understanding of potential error causes and effects is essential for researchers to accurately explain their findings and minimize processing workflow errors. While this article provides valuable insights into these matters, it is crucial to recognize that a comprehensive analysis of each specific error source goes beyond the current scope and may require dedicated research efforts. Additionally, it is important to note that specific examples of SAR phase interpretation are beyond the scope of this paper. While these components are vital for making informed decisions during InSAR processing, the objective of this paper is to establish a foundational understanding of the overarching landscape of InSAR error sources, laying the groundwork for more focused investigations in subsequent studies. In summary, we seek to sort and explain the different error sources with notable clarity so that readers can build a comprehensive view of the total InSAR error budget. The impacts of different error types vary depending on the sensor wavelength.