Satellite data have the potential to significantly enhance railway operations and drive the digitization of the rail sector. In the context of railways, satellite data primarily refers to the use of Global Navigation Satellite System (GNSS) data for applications such as navigation, positioning, and signalling. However, remote sensing data from Earth Observation (EO) satellites remain comparatively underutilized in railway applications. While the use of GNSS data in railways is well documented in the literature, research on EO-based remote sensing methods remains relatively limited. This paper aims to bridge this gap as it presents a comprehensive review of the use of satellite data in railway applications, with a particular focus on the underexplored potential of EO data. It provides the first in-depth analysis of EO techniques, primarily examining the use of synthetic aperture radar (SAR) and optical satellite data for key applications for infrastructure managers and railway operators, such as assessing track stability, detecting deformations, and monitoring surrounding environmental conditions. The goal of this review is to explore the diverse range of EO-based applications in railways and to identify emerging trends, including the integration of thermal EO data and the novel use of SAR for dynamic and predictive analyses. By synthesizing existing research and addressing knowledge gaps, the presented review underscores the potential of EO data to transform railway infrastructure management. Enhanced spatial resolution, frequent revisit cycles, and advanced AI-driven analytics are highlighted as key enablers for safer, more reliable, and cost-effective solutions. This review provides a framework for leveraging EO data to drive innovation and improve railway monitoring practices.

The development of new technologies, which include advanced sensors and the application of artificial intelligence, has led to the moment that some operations done by workers can be changed in the maintenance domain. Visual inspection is one of the operations that will be changed in the future. Today, there are various legal regulations regarding the maintenance and control of vehicles in the transport sector, which cause additional costs for operators. There is a need to reduce those costs by integrating autonomous robots for the visual inspection of various vehicles. In addition to reduced costs, the benefits are reflected in improved human safety, greater efficiency, and reduced errors during the visual controls. This paper explores various applications of autonomous robots in various transport domains, including rail systems, road and bridge networks, aerospace, and maritime industries. It also shows a real example of visual control of locomotive undercarriage in railways.