# Space Debris In-Orbit Detection with Commercial LiDAR Sensors
## 1 Introduction  
Space debris refers to artificial objects in Earth's orbit that no longer serve an operational purpose. These objects can vary in size, from small particles to defunct satellites or abandoned rockets. The issue of space debris has been growing over the decades as a result of the increase in space activities. The increase in space debris is primarily due to the proliferation of satellites in orbit, commercial and military space launches, and accidental collisions in space. The remnants of rockets and deorbited satellites also contribute to debris [1]. Space debris poses a significant risk to space missions and the International Space Station. Collisions with space debris can damage or destroy operational satellites and generate more fragments [2; 3; 4]. The accumulation of space debris also raises environmental concerns. Various strategies have been proposed to manage and mitigate space debris, including active cleanup through technologies such as nets or robotic arms, and improving guidelines for the safe disposal of satellites at the end of their operational life [5; 6]. The scientific and space community continually conducts research on space debris, including data collection and tracking of objects in orbit, with the aim of better understanding the problem and developing effective solutions [7; 8; 9]. At present, ground-based RADAR and LiDAR are the main research tools that contribute to space debris cataloging databases [10; 11; 12; 13]. However, only 10% of this debris has been detected [12], as most of it consists of very small particles, below 10 cm in diameter, and becomes less detectable under the influence of the atmosphere. In contrast, space-based optical imaging is another approach for detecting and tracking space debris, as it avoids environmental constraints such as atmospheric interference. This method enables capturing high-resolution images and uses advanced imaging algorithms to effectively enhance the resolution and detectability of space debris [14; 15; 16]. However, these techniques come with significant challenges, including the complexity of deploying high-resolution cameras in orbit, the increase in payload weight, and the intensive data processing required, which leads to a high power consumption. In this context, emerging and innovative technologies are being explored for the detection and tracking of space debris. In conclusion, this article is based on the novel concept of using commercial automotive LiDAR sensors, which were originally developed by the automotive industry to enable autonomous vehicles to detect and avoid objects. Because of their compact size, low weight, and minimal power requirements, these sensors could be deployed onboard CubeSats to detect space debris in Earth's orbit. Although LiDAR sensors are widely used in various terrestrial applications and are also being used in space for Earth-observation purposes, their potential for space debris in-orbit detection remains largely unexplored. The aim of this work is to propose a novel application of LiDAR technology to measure the density of space debris that pose significant risks to current and future space operations [17]. Although this study does not discuss the technical specifications of the LiDAR sensors themselves, it focuses on how such sensors can be integrated into small satellites to enhance debris tracking capabilities. The use of LiDAR in this specific context has not been widely discussed or implemented to date, and its application could provide critical insights for the management of space debris. LiDAR (Light Detection and Ranging) is similar to microwave RADAR (Radio Detecting and Ranging) in remote sensing, but with much shorter wavelengths (optical or infrared). LiDAR is an active sensor (laser or led) that emits an electromagnetic pulse and receives the signal that bounces back with a photo/iR detector. Because of the much shorter wavelength, lasers can be modulated much faster and the laser beams can be collimated to a much smaller spot.