## 4 Verification of the Measurements from the EMC Topological Model
These values are as follows: \(a_{s1}^{(i)}\approx 0\), due to the space's short distance, and \(a_{s1}^{(o)}=a_{s2}^{(o)}=a_{s1}^{(o)}=a_{s3}^{(o)}=15.5\) dB, due to the space's total distance, which was equal to 4.5 m.  
Taking into account the above, for the scenario presented in Figure 3, the resultant value of the internal disturbing signal \(E_{l}^{(i)}\), as seen in Equation (2), at the EuT has the one component, i.e., where \(a_{s1}^{(i)}\approx 0\). The values of the components of the external disturbing signal \(E_{l}^{(o)}\), as seen in Equation (3), can be calculated by (13), which has the following form:  
\[\left[E_{1}^{(o)}\right]=\left[ \begin{array}{c}E_{\Pi_{1}}^{(o)}\\ E_{\Pi_{2}}^{(o)}\\ E_{\Pi_{3}}^{(o)}\end{array} \right]=\left[ \begin{array}{c}100\\ 010\\ 001\end{array} \right]\left[ \begin{array}{c}160\ \mathrm{dB}\mathrm{\mu V}/\mathrm{m}\\ 154\ \mathrm{dB}\mathrm{\mu V}/\mathrm{m}\\ 146\ \mathrm{dB}\mathrm{\mu V}/\mathrm{m}\end{array} \right]-\left[ \begin{array}[] {c}115\ \mathrm{dB}\\ 111\ \mathrm{dB}\\ 105.5\ \mathrm{dB}\end{array} \right]-\left[ \begin{array}{c}15.5\ \mathrm{dB}\\ 15.5\ \mathrm{dB}\\ 15.5\ \mathrm{dB}\end{array} \right]=\left[ \begin{array}{c}29.5\ \mathrm{dB}\mathrm{\mu V}/\mathrm{m}\\ 27.5\ \mathrm{dB}\mathrm{\mu V}/\mathrm{m}\\ 25\ \mathrm{dB}\mathrm{\mu V}/\mathrm{m}\end{array} \right]. \tag{31}\]  
Practically, the best way to verify the correctness of the EMC topological model is to compare the values of the disturbing signals at the EuT, i.e., \(E_{\Pi_{1}}^{(i)},E_{\Pi}^{(o)},E_{\Pi}^{(o)}\), and \(E_{\Omega}^{(o)}\), which can be calculated by using the model to measure their values using a spectrum analyzer. The theoretical values calculated by the EMC topological model and the values in situ measured using a spectrum analyzer of all the disturbing signals at the EuT are compared and expressed in Figure 5, where the lines show the values measured by the spectrum analyzer and the circles show the values calculated by using the described topological model. For practical reasons, the obtained number of test results is small due to the limited number of measurements on an operating navy ship. However the results of these measurements are unique on a global scale. The smallest difference between the calculated (25 dB\(\mu\)V/m) and measured (24 dB\(\mu\)V/m) values of the same disturbing signal, i.e., (\(E_{\Omega}^{(o)}\)) at the EuT, is 0.9 dB, or 3.7%. These results are acceptable. However, the largest difference between the calculated (29.5 dB\(\mu\)V/m) and measured (36.5 dB\(\mu\)V/m) values of the same signal, i.e., (\(E_{\Pi_{1}}^{(i)}\)) at the EuT, is 7 dB, or 19%, which is relatively high. Such a discrepancy in the results is influenced by the complexity and tightness of the ship's construction. However, simulation studies using this model allow us to analyze variations in the location of a ship's devices and systems that are sensitive to EM disturbances. This allows us to develop an optimal solution in this respect. Often, it is not important to accurately determine the value of a disturbing signal at the selected location of the EuT, but the identification of where this signal will potentially be the smallest allows us to determine the best EuT location. Due to time and cost constraints, such an approach is the only one that is acceptable in the practice of a ship's exploitation or the rebuilding of a ship's electrical and electronic equipment. Figure 4: The attenuation characteristics of the shielding planes from Figure 3.  
Summarizing the results of the comparison and taking into account practical aspects, especially the complex character of EMC investigations, we conclude that the EMC topology model is useful for practical applications, particularly when designing studies regarding the optimal locations for a ship's electrical and electronic equipment.