## 1 Introduction  
Our living environments are intricate ecosystems that encompass various elements, including people, infrastructure (such as roads and buildings), living organisms (like trees, forests, and lakes), and diverse non-homogeneous components (such as street furniture and light poles). These dynamic ecosystems require continuous observation, planning, and management (OPM) to ensure sustainable development and effective functioning. Established principles for preserving natural resources [1] necessitate the integration of specific geospatial technologies that provide a suite of scientific and engineering tools essential for monitoring and maintaining ecosystems. Among geospatial tools, mobile mapping systems (MMSs) stand out as advanced solutions capable of efficiently collecting large volumes of diverse, non-homogeneous data, which are crucial for various OPMapplications. By integrating MMSs into geospatial workflows, we can significantly enhance our ability to manage and sustain the complex environments in which we live. The evolution of MMS technologies flourished nearly three decades ago, pioneered by research organizations and technological companies worldwide. A key milestone in this evolution was the global positioning system (GPS), which became fully operational in 1993 [2], followed by other global navigation satellite systems (GNSS), including GLONASS, Galileo, and BeiDou [3]. The earliest MMS solutions [4] typically consisted of a GNSS receiver, an inertial measurement unit (IMU), and 360\({}^{\circ}\) cameras utilizing direct-georeferencing techniques [5]. Initially, the outputs from these systems were wide-angle (360-degree) stitched photographs [6] tagged with location data. Those images were displayed on online platforms, allowing users to virtually explore unseen locations--a trend that even continues today. Figure 1 demonstrates a graphic of a recent iteration of one of the most successful MMSs developed to capture 360-degree images [7]. Virtual tours have gradually become one of the most accessible technologies for virtually navigating in major cities worldwide. As MMS technologies have advanced, they now offer far more than just 360-degree imagery; they provide highly detailed spatial data and models that enhance applications in urban planning [8], infrastructure management [9], and environmental monitoring [10]. This ongoing evolution continues to push the boundaries of how we explore and manage our ecosystems. Development of MMSs requires vast knowledge about sensors, calibration methods, hardware, and software. The evolution of MMSs has been driven by the integration of advanced sensors such as multi-camera setups, LiDARs, and GNSS and IMUs, which have enabled the collection of high-resolution, multi-spectral, and spatially accurate data. Among the suite of sensors used in modern MMSs, cameras play an indispensable role [11]. The advent of digital photography has revolutionized this field, making digital cameras essential sensory elements in any MMS. Photogrammetry and computer vision have developed in tandem, addressing similar challenges such as camera lens distortion modeling, structure from motion (SfM), and pattern recognition and classification problems. These two fields are deeply intertwined, with numerous methods created under different terminologies yet targeting common problems [12]. Today, MMSs integrate complex sensor models for multi-camera setups and other sophisticated settings, enhancing their functionality. Typically, multiple cameras are employed in an MMS to capture a comprehensive view of the surrounding environment [13]. These setups often include a combination of projective, fisheye, or wide-angle cameras, together providing 360-degree coverage. The number and arrangement of cameras can  
Figure 1: A mobile mapping system was developed by Google to be mounted on a car. The customized LiDAR configurations in Google’s car show how the system is designed for collecting suitable data for 360 virtual tour web-portal.