# Functionality of the Search and Rescue Transponder (SART) in Maritime Search and Rescue Actions
## 2 Materials and Methods
The following ratings are used for assessing the occurrence of interference: weak (0 points), medium (1 point), and strong (2 points). Weak interference means that the radar image is clear and easy to interpret. Moderate interference means that the interpretation of the image becomes difficult. Strong interference means that important data cannot be read or actions cannot be performed (e.g., acquiring an object for tracking). Table 3 provides the main information on the rating method. In addition, at each distance interval, the navigator will assess the overall clarity of the radar image and express it as a percentage. To assess the applicability of the SART device, the effectiveness of a component will be determined. Effectiveness is a measure of success and is calculated as the ratio of the number of positive occurrences to the total number of attempts (Formula (1)). \[W=\frac{E}{N} \tag{1}\]  
where,  
W--effectiveness;  
Figure 6: Research field—liferaft with SART in the proximity of the searching unit. In this way, the effectiveness of two parameters, A1 and A2, will be determined. The effectiveness of the shape will be calculated as the arithmetic average of the three detection ranges (Formulas (2) and (3)). According to the SART user manual, at distances of 5-6 Nm, the navigator should observe dots; at distances of 2-3 Nm, the navigator should observe arcs; and at distances of less than 1 Nm, the navigator should observe concentric circles. These expected signal shapes will be studied in the following ranges: 4 Nm and greater, 1-3 Nm, and less than 1 Nm. The amount of interference (A4) will be evaluated separately as a function of the relationship between the level of interference and the distance and will be shown in the graph. \[W_{s}=\frac{W_{n}}{n} \tag{2}\]  
\[W_{n}=\sum_{i=1}^{n}\frac{E_{i}}{N_{i}} \tag{3}\]  
where,  
\(W_{s}\)--effectiveness of shape compatibility;  
\(W_{n}\)--effectiveness of shape compatibility in the \(i\)-range;  
\(n\)--number of ranges;  
\(E_{i}\)--number of positive assessments in \(i\)-range;  
\(N_{i}\)--total number of attempts in \(i\)-range. The procedure discussed above for conducting the experiment and analyzing the results will allow the study to achieve its objectives. The study, conducted at varying distances and with different settings, will primarily verify the impact of the marine radar image on the success of search and rescue operations. It should also be noted that when a ship approaches an object after detecting a signal but is unable to locate it, a search plan should be developed in accordance with the IAMSAR Manual. This is a requirement of the International Maritime Organization (IMO). The manual provides guidelines, recommendations, and advice for search and rescue operations at sea. One key element of the search plan is defining parameters for the search pattern, such as track spacing during the scan. This spacing must be optimized to ensure the detection of the object. Calculations [2] are made using Formula (4). \[S=S_{u}\times f_{w} \tag{4}\] \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Label** & \begin{tabular}{c} **Component** \\ **Description** \\ \end{tabular} & **Scale** & **Evaluation Range** & \begin{tabular}{c} **Evaluation** \\ **Description** \\ \end{tabular} \\ \hline A1 & \begin{tabular}{c} Detectability of the SART device \\ by ship radar \\ \end{tabular} & Two-level & 0–1 & \begin{tabular}{c} 0—not detected \\ 1—detected \\ \end{tabular} \\ \hline A2 & \begin{tabular}{c} Distinctiveness of the liferaft \\ echo on the radar image \\ \end{tabular} & Two-level & 0–1 & \begin{tabular}{c} 0—not visible \\ 1—visible \\ \end{tabular} \\ \hline A3 & \begin{tabular}{c} Compatibility of the response \\ signal shape \\ \end{tabular} & Two-level & 0–1 & \
\begin{tabular}{c} 0—not compatible \\ 1—compatible \\ \end{tabular} \\ \hline A4 & Interference in the radar image & Three-level & 0–2 &
\begin{tabular}{c} 0—weak \\ 1—medium \\ 2—strong \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table}