The Efficiency of Drones Usage for Safety and Rescue Operations in an Open Area: A Case from Poland

The use of unmanned aerial systems (UAS) is becoming increasingly frequent during search and rescue (SAR) operations conducted to find missing persons. These systems have proven to be particularly useful for operations executed in the wilderness, i.e., in open and mountainous areas. The successful implementation of those systems is possible thanks to the potential offered by unmanned aerial vehicles (UAVs), which help achieve a considerable reduction in operational times and consequently allow a much quicker finding of lost persons. This is crucial to enhance their chances of survival in extreme conditions (withholding hydration, food and medicine, and hypothermia). The paper presents the results of a preliminary assessment of a search and rescue method conducted in an unknown terrain, where groups were coordinated with the use of UAVs and a ground control station (GCS) workstation. The conducted analysis was focused on assessing conditions that would help minimise the time of arrival of the rescue team to the target, which in real conditions could be a missing person identified on aerial images. The results of executed field tests have proven that the time necessary to reach injured persons can be substantially shortened if imaging recorded by UAV is deployed, as it considerably enhances the chance of survival in an emergency situation. The GCS workstation is also one of the crucial components in the search system, which assures image transmission from the UAV to participants of the search operation and radio signal amplification in a difficult terrain. The effectiveness of the search system was tested by comparing the arrival times of teams equipped with GPS and a compass and those not equipped with such equipment. The article also outlined the possibilities of extending the functionality of the search system with the SARUAV module, which was used to find a missing person in Poland.

Noise Assisted Image Encryption and Decryption using 2-D Chaotic System

In this paper, a new two-dimensional (2-D) chaos-based color image encryption and decryption scheme is proposed in which the noise signal is selected randomly to set the initial values for a chaotic system which also enhances the security of the system. The 256-bit hash value of noise is transformed into one-time initial values for the state variables of this proposed chaotic system. XOR operation is further carried out to diffuse the pixels. Finally, statistical and security analyses are performed for understanding the effectiveness of the proposed system. Experimental results confirm that the proposed chaos-based cryptosystem is efficient and suitable for information (image) transmission in a highly secured way.

Wireless Image Transmission Interference Signal Recognition System Based on Deep Learning

In the process of wireless image transmission, there are a large number of interference signals, but the traditional interference signal recognition system is limited by various modulation modes, it is difficult to accurately identify the target signal, and the reliability of the system needs to be further improved. In order to solve this problem, a wireless image transmission interference signal recognition system based on deep learning is designed in this paper. In the hardware part, STM32F107VT and SI4463 are used to form a wireless controller to control the execution of each instruction. In the software part, aiming at the time-domain characteristics of the interference signal, the feature vector of the interference signal is extracted. With the support of GAP-CNN model, the interference signal is recognized through the training and learning of feature vector. The experimental results show that the packet loss rate of the designed system is less than 0.5%, the recognition performance is good, and the reliability of the system is improved.

Efficient Transmission of 2D Chaotic Maps Encrypted Images with DWT-Based SC-FDMA LTE System

The single-carrier frequency division multiple access (SC-FDMA) is a promising technique that has been adopted as an uplink transmission scheme in the long-term evolution (LTE) cellular system. This is attributed to its advantages such as the low peak-to-average power ratio (PAPR) and the utilization of frequency-domain equalizers to resolve the problem of inter-symbol interference (ISI). In this paper, a Discrete Wavelet Transform (DWT) based SC-FDMA system is proposed for the effective transmission of encrypted images. The 2D Chaotic baker map encryption algorithm has been used to encrypt images to enhance their security during transmission via SC-FDMA- based systems. The performance of the process of encrypted image transmission using the 2D Chaotic baker map algorithm with wavelet transform-based SC-FDMA (DWT SC-FDMA) system is evaluated in terms of different performance metrics, with comparison to Discrete Fourier Transform SC-FDMA (DFT SC-FDMA) and, Discrete Cosine Transform SC-FDMA (DCT SC-FDMA) systems. The viability of the proposed scheme was tested with different wireless channel models and different subcarriers mapping schemes. Experimental results show that the proposed method of the encrypted image transmission via the DWT SC-FDMA system provides a remarkable performance gain compared to the other versions of the SC-FDMA system in terms of the PSNR, and the BER metrics in the wireless channel models. It also demonstrates the effectiveness of the proposed scheme and adds a degree of encryption to the transmitted images through the wireless channels.