# Functionality of the Search and Rescue Transponder (SART) in Maritime Search and Rescue Actions
## 1 Introduction
A case was reported in which the SART device could not be detected during a real-life emergency situation involving a person calling for help. Ships were passing very close by but were unable to receive the device's signal. An investigation was then conducted, revealing issues with the radar settings (the automatic tuning option limited the signal reception) and the height at which the device was placed. These factors are crucial for conducting search and rescue operations and for the chances of  
Figure 1: SART image on the radar screen depending on the distance from the vessel. (**a**) Distance of 5–6 Nm, radar range 12 Nm; (**b**) Distance of 2–3 Nm, radar range 6 Nm; (**c**) Distance \(<\) 1 Nm, radar range 6 Nm. saving a human life. It is essential to properly educate maritime navigators on the use of radars and sailors in general on the use of the SART device in emergency situations. The device's performance and physical characteristics are verified by the manufacturers. However, conducting experiments with ships under different weather conditions or settings is not common practice, as it is both costly and time-consuming. Experiments are sometimes conducted in the laboratory or on land, which means that the influence of many factors is often neglected. The most commonly studied element in scientific research is the detection range of the SART device and the signal strength. Other elements are rarely studied. There is little to no research on the relationship between radar settings and the presence of a radar reflector (other aid supporting the detection of the object by radar) on a survival craft. There is a gap in scientific research. The authors prepared and conducted an experiment addressing some of the issues related to the effectiveness of the SART. They developed a method and established effectiveness indicators. The method includes both a qualitative and a quantitative assessment of the data. Performance indicators include signal detectability, echo distinctiveness, response signal shape, interference level, and radar image readability. This work contributes to the advancement of the field of maritime search and rescue. The results are also valuable for officers and sailors, as they provide knowledge on potential issues. Practical knowledge, supported by theory, is crucial for ensuring safety at sea and can be used to improve seafarers' competence. The results are also valuable for optimizing SAR (search and rescue) operations. Below are some references to the requirements, test reports, and scientific papers related to the use of the SART device in search and rescue actions. Planning and conducting SAR operations are based on the jointly developed International Aeronautical and Maritime Search and Rescue Manual by IMO and ICAO (vols. 2 and 3) [1,2]. On ships, these procedures are additionally supported by publications such as ALRS vol. 5 GMDSS [3]. The requirement for equipping ships with these devices (one or two) is established by the SOLAS Chapter III convention [4]. The latest operational standards for SART devices are contained in the IMO MSC.510(105) resolution [5]. The foundations of modern SAR operations are presented in [6]. The results of studies on detectability range, antenna height, and the effect of obstacles (e.g., liferaft components) obscuring the device are presented in [7]. It was emphasized that the impact of the radar reflector on the SART's detectability by the ship's radar was not studied. However, it was noted that detection performance may be reduced. The case study and results of the experiment using the radar's automatic features are discussed in [8]. The performance of SART devices in actual sea weather conditions is presented in [9; 10; 11]. The use of SARTs and detection issues are discussed in [12]. The authors also propose modifications to the device to enhance detection efficiency through other methods. The authors of the experiment [13] conducted comparative tests of the SART 9 GHz, AIS-ART, and EPIRB involving aircraft.