## 1 Introduction  
With the prevailing tendency of integrating an extensive range of electronic devices into vehicles, the electromagnetic environments of vehicular communication systems have grown increasingly intricate. The intensity of electromagnetic interference (EMI) amplifies in correlation with the complexity of the electromagnetic environment [1; 2; 3; 4; 5; 6; 7; 8]. EMI stands out as the principal factor contributing to electromagnetic compatibility (EMC) issues [9; 10; 11; 12; 13]. It is responsible for various complications, including diminished communication quality and the disruption of regular communication processes. Several EMC evaluation models have been proposed, including the ACAT model [14; 15], the IEMCAP model [16; 17], and the IAP model [18]. Recently, a modified four-level evaluation model was proposed [19]. The traditional four-level evaluation model is widely regarded as one of the most enduring and frequently employed models in the field [20]. The design of the traditional four-level assessment model can be broken down into four hierarchical levels. By first performing a rough assessment based on the signal amplitude, the least likely potential EMI sourcescan be eliminated directly. Next, the second-level EMC assessment is performed based on spectral analysis, and detailed prediction and performance analyses are performed as the third and fourth levels of the EMC assessment process. However, due to advancements in vehicular electronic technology, the conventional model has become restricted, antiquated, and inadequate, particularly concerning armored vehicular communication systems. The traditional four-level evaluation model exhibits several limitations when employed in the evaluation of electromagnetic compatibility within armored vehicular communication systems:  
(1) The potential mutual interference caused by the simultaneous operation of multiple electronic devices is not taken into consideration. (2) An evaluation of whether the decreased isolation between antennas meets the electromagnetic compatibility requirements of a system is not performed when vehicle-mounted antennas are functioning simultaneously. (3) An evaluation of whether the reduced sensitivity of the radio receiver meets the electromagnetic compatibility requirements of a system is not conducted. (4) The impact of the actual terrain environment on the communication distance is not investigated. (5) The evaluation criteria used for evaluating vehicular communication quality are overly simplistic and unsuitable for digital communication systems. In recent years, remote sensing technology has developed rapidly and is now widely used, e.g., LiDAR localization technology [21; 22; 23; 24]. Since high-precision digital maps are easy to acquire, they are widely used in wireless communication [25; 26; 27; 28]. The communication distance and quality of a vehicular communication system are easily affected by complex terrain and geomorphology factors, thus increasing radio wave propagation loss and seriously affecting communication performance. In light of the progress in this field, it has become imperative to tackle the aforementioned issue by developing an evaluation model that aligns with the specific characteristics of armored vehicular communication systems and the application of digital maps. Therefore, in this paper, we introduce a modified five-level evaluation model, which is based on digital maps, for conducting EMC evaluations of armored vehicular communication systems. The reduction in the sensitivity of a radio receiver is directly determined by the actual power it receives, wherein the path loss of radio propagation plays a critical role in influencing both the actual power received by the radio receiver and the achievable communication distance. Digital maps are extremely intuitive and accurate tools for obtaining geographical information, including vehicle distances, terrain surface, terrain height, and land cover. Such information plays a crucial role in determining the path loss of radio wave propagation.