# Propagation Attenuation Maps Based on Parabolic Equation Method +
## 1 Introduction
Modern transceivers are mainly based on SDR technology [24; 25]. On the other hand, the possibility of designing radio waveforms allows for the implementation of an additional sensing (i.e., spectrum monitoring) process [26; 27]. These relatively simple methods of empirical measurements will enable the building of electromagnetic situation awareness [23; 27; 28]. However, the results obtained refer only to the area where MANET is currently operating. Thus, these solutions are not sufficient to design the network in new terrain and assess the range capabilities of its nodes. Hence, the search for new solutions of this type is significant, especially in the military MANETs. Different propagation models can be used to create REM. They can be classified into two main groups, i.e., statistical models and deterministic models [20]. We propose using PAMs, which can be the basis for determining coverage maps for network nodes. As shown in [28; 29; 30; 31], the determined PAM can also be used in the process of analyzing the location of sensors to monitor the electromagnetic situation. The idea of the PAM was presented in [32], but the mechanisms of their generation were not described. In this paper, we focus on the detailed description of the novel PAM algorithm that was initially outlined in [33]. The proposed solution is based on three elements:  
* determining the attenuation for given terrain profiles on specific azimuths outgoing radially from the transmitter (TX);
* using the PEM [34; 35; 36] for attenuation calculation along with the profiles;
* using linear interpolation to determine the attenuation values between the profiles to determine the entire PAM. According to the best knowledge of the authors, the proposed approach can be considered original. The choice of PEM and linear interpolation resulted from the limited computing power of the devices on which REM will be implemented. In the general case, these methods may also be replaced by others, which provide similar abilities. The basic PEM approach allows considering the terrain topography (with or without building heights), the electrical ground, and air-refraction parameters for determining propagation attenuation (i.e., path loss). In this paper, we present the novel PAM creation algorithm. To the best of the authors' knowledge, it is an innovative and original solution. Typically, the PEM is used to determine the attenuation along a given propagation direction related to a specific terrain profile as a function of height above ground level. We show how to use the PEM at a given height of the receiving antenna to determine the attenuation on the surface. The remainder of the paper is organized as follows. Section 2 provides a brief overview of the REM. The idea, short description of PEM, and algorithm of the proposed PAM approach with exemplary results are shown in Section 3. In Section 4, we analyze the efficiency of creating the PAM as a function of its dimensions. Next, in Section 5, an evaluation of the PAM accuracy versus angular resolution of terrain profiles is shown. A summary of the paper is presented in Section 6.