# TinyGS vs. SatNOGS: A Comparative Analysis of Open-Source Satellite Ground Station Networks
## 1 Introduction  
In the current era, marked by technological advances and innovations in the space sector, we have seen a notable increase in the presence of satellites in orbit [1]. This growth is driven, in part, by the ease and reduced cost of the development and launch of satellites, enabling a variety of entities, such as universities [2; 3; 4] and small companies, to actively participate in this ecosystem. However, beyond construction and launch, there is also a crucial challenge: satellite monitoring. To address this, ground stations (GSs) are needed, as they play an important role in communicating with satellites, serving as the link between the \"ground\" and these devices orbiting Earth several kilometers above us. This communication is vital to receiving/sending data from/to the satellite, providing access to scientific data, weather data, satellite telemetry data, and other valuable information [5]. However, if the satellite is not in a geostationary orbit (GEO), that is, not over the same location, there are times when satellite-GS communication becomes impossible, particularly for low-Earth orbit (LEO) satellites (which are the main satellites with which both SatNOGS and TinyGS GS communicate), as they are in low orbits with high speeds, as the GS has only a few minutes to communicate with the satellite [6]. To extend this communication time and make it as extensive as possible, a set of GSs must be built in strategic positions. However, studying the number of required GSs and their positions is not an easy task. This is because there are various factors affecting communication between satellites and GSs, such as the satellite's elevation angle and rain attenuation. Nevertheless, there are methodologies that can be employed to study this number and these positions [6; 7]. Additionally, to facilitate multiple ground stationoperations remotely, the creation of a global management interface, a network [5], is often required. Consequently, the creation of such infrastructure can be a challenging, costly, uninteresting, and time-consuming task. In many cases, such as in universities and small businesses, the primary interest and focus lie solely in the development of satellites, not in the development and study of a GS network. Therefore, the existence of an already built and financially accessible infrastructure would be ideal. Examples of open-source projects with such infrastructure include SatNOGS [8] and TinyGS [9] and are characterized by being non-profit projects, easily accessible, and suited for educational, research, non-profit experimental, and amateur work. Both projects are among the largest open-source ground station networks, aiming to provide an easy and low-cost alternative for communication between Earth and satellites, particularly LEO satellites. Designed for tracking, receiving, and decoding satellite signals, they seek to democratize access to space by providing a decentralized infrastructure. Besides their accessibility and simplicity, they boast an active and collaborative community capable of providing support and promoting participation from anyone. Consequently, for satellite developers whose sole objective is satellite development or even for space and communication enthusiasts, these two projects emerge as effective and accessible solutions. Thus, if a satellite developer integrates into one of these networks, they can focus their efforts on building and launching satellites without the need to create their own network infrastructure. They can also leverage existing GSs and design the satellite in accordance with the bands and frequencies most commonly used by the project's GSs or those better distributed geographically, in accordance with the radio modulations (e.g., FSK and GFSK) supported by each project [8,9], etc. Additionally, if they join and build their GS, while it is not receiving data from the intended satellite, it can communicate with other satellites and thereby contribute to the community.