Emergency Beacon Research Articles

SAFEGUARDING AEROSPACE EMERGENCIES WITH SATELLITE COMMUNICATION METHODS

This paper explores how communication technologies in aerospace save lives and missions. It helps pilots and astronauts keep in contact with ground teams to make decisions and keep everyone safe. Without good communication, things can get dangerous fast. The communication technologies we use in aerospace are Short Range Radio, Medium Range Radios, Satellite Communication, and Emergency beacons. This satellite communication plays an important role in improving emergency management. It explains how they help with every part of emergencies: getting ready, acting fast during crises, recovering afterward, and stopping future problems. Satellites are vital for facilitating quick reactions, pinpointing exact locations, and ensuring that various communication tools, such as phones, radios, and data systems, work seamlessly together. This communication approach leads to more effective emergency responses, better outcomes, and ultimately, greater safety for all. Keywords -: Emergency Management, Architectural approaches, terminal issues, Uplink and Downlink, Satellite orbits, Positioning Services, Space-Based Communication

Design of a Baseband Signal for the 406 MHz Satellite Emergency Radio Transmitter Based on STM32

The baseband signal of the 406 MHz COSPAS-SARSAT emergency beacon is a 144-bit or 112-bit data with 0 and 1 code, including the information bits and error correcting check bits. In order to improve the coding efficiency of the baseband signal for the 406 MHz transmitter in the STM32 micro-controller, this paper proposes a calculation method for the first BCH error correcting code (BCH-1) and the second BCH error correcting code (BCH-2) of the COSPAS-SARAST transmitter. First, conduct the data coding process by 64-bit integral data; then, compute the BCH (127, 106) code and the BCH (63, 51) code to obtain the respective error correcting codes for improving coding rate; next, generate the baseband signal according to the GB 14391-2021 coding format; finally, modulate the baseband signal into a 406 MHz-RF signal, send it out and complete the task of distress alerting. The experimental results show that the proposed STM32 microcontroller-based baseband signal generation method is effective, and the EPIRB (Emergency Position Indicating Radio Beacon) designed based on this method has reached the industry standard.

Position Estimation of Autonomous Underwater Sensors Using the Virtual Long Baseline Method

This article contains a description of a mathematical model of an acoustic system for positioning autonomous underwater sensors using the virtual long base method, which can be used during the vessel’s collection of information over the deployed underwater network of autonomous sensors (underwater wireless sensors network), during the initial determination of the geographical position of the bottom long baseline elements or search, including cooperative, with the use of a swarm of autonomous surface vehicles (UASV) of emergency submerged objects equipped with an emergency beacon (for example, aircraft and ships); The article provides a scheme of an experimental set of equipment, as well as a description of the conducted field experiments and their results.

Your Phone as a Personal Emergency Beacon: A Portable GSM Base Station to Locate Lost Persons

Access to emergency numbers such as 911 or 112 is generally universally available to cell phone users. Nevertheless, emergencies may occur in areas without cell phone coverage, for example, in remote areas frequented by climbers or hikers. In this article, we describe the design, development, and evaluation of a global system for mobile communications (GSM) base station that can be placed in a vehicle (car, plane, helicopter, etc.) to locate a lost person with an active GSM phone. The system includes the resources to provide a good estimation of the location of the phone, allowing the rescue team to significantly narrow its search and to establish communication with the person where possible, as the system also provides GSM coverage.

Effect of 406 MHz ELTs and COSPAS-SARSAT Cessation of 121.5 MHz ELT Monitoring on Search and Rescue Duration for General Aviation Aircraft Accidents in the Contiguous United States

Emergency Locator Transmitters (ELTs) are credited with saving hundreds of lives every year in the United States. Following an aircraft accident, these devices transmit an emergency beacon signal to the COSPAS-SARSAT satellite network, directing search and rescue forces to the crash site. In recent years, this constellation has been plagued by ELT false alarms, propagating a technology transition to new 406 MHz ELT systems. In 2009, the group ceased monitoring of 121.5 MHz ELTs, degrading search and rescue capability for legacy ELTs. The Federal Communications Commission twice attempted to enact regulations to mandate industry-wide transition to 406 MHz ELTs, however, their efforts have met strong resistance by pilot advocacy groups. The purpose of this study was to determine if 406 MHz ELTs resulted in lower search and rescue durations than 121.5 MHz systems. Furthermore, the study sought to discover if the cessation of 121.5 MHz ELT monitoring in 2009 resulted in a change in search and rescue mission duration for legacy ELTs. The study collected data from an Air Force Rescue Coordination Center search and rescue database for search missions occurring between 2006-2011. To compare search durations of 406 MHz and 121.5 MHz ELTs, data was assessed using orthogonal contrast testing between historical mission durations. The same contrast technique was applied to 121.5 MHz ELT missions conducted from 2006-2008, which used the COSPAS-SARSAT network, and missions conducted from 2009-2011, in which 121.5 MHz satellite detection was deactivated. The study revealed 406 MHz ELTs offer a statistically significant advantage in search duration over 121.5 MHz ELT models. Additionally, the study determined there was no significant difference in mission durations for 121.5 MHz ELTs monitored by the COSPAS-SARSAT network and those missions which did not receive satellite coverage. This research will likely aid both regulators and advocacy groups in shaping future policy decisions for mandatory 406 MHz ELT implementation.

A New Emergency Handling Mechanism based on IEEE 802.15.4 for Health Monitoring Applications

The recent advances in wireless communication systems and semiconductor technologies are paving the way for new applications over wireless sensor networks. Health-monitoring application (HMA) is one such emerging technology that is focused on sensing and reporting human vital signs through the communication network comprising sensor devices in the vicinity of the human body. The sensed vital signs can be divided into two categories based on the importance and the frequency of occurrence: occasional emergency signs and regular normal signs. The occasional emergency signs are critical, so they have to be delivered by the specified deadlines, whereas the regular normal signs are non-critical and are only required to be delivered with best effort. Handling the occasional emergency sign is one of the most important attributes in HMA because a human life may depend on correct handling of the situation. That is why the underlying network protocol suite for HMA should ensure that the emergency signs will be reported in a timelymanner. However, HMA based on IEEE 802.15.4 might not be able to do so owing to the lack of an appropriate emergency-handling mechanism. Hence, in this paper, we propose a new emergency-handling mechanism to reduce the emergency reporting delay in IEEE 802.15.4 through the modified superframe structure. A fraction of an inactive period is modified into three new periods called the emergency reporting period, emergency beacon period, and emergency transmission period, which are used opportunistically only for immediate emergency reporting and reliable data transmission. Extensive simulation is performed to evaluate the performance of the proposed scheme. The results reveal that the proposed scheme achieves improved latency and higher emergency packets delivery ratio compared with the conventional IEEE 802.15.4 MAC.

COSPAS-SARSAT을 이용한 탐색구조 신호 보안

The international COSPAS-SARSAT program is a satellite-based search and rescue distress alert detection and information distribution system and best known as the system that detects and locates emergency beacons activated by aircraft, ships and so on. However, the current message format of the system is not encrypted so that, if the rescue signal can be intercepted by the unintended receivers, the subsequent rescue activities can be handled in a hostile environment. So, this article concerns how to deal with the rescue signals in a secure way and proposes some adequate encryption methods and the corresponding key management.

Mobile Handsets as Sensing Nodes in an Auto-Configured Hierarchical Cognitive Radio Network Scheme for Immediate Post-Disaster Communications

A critical problem after a natural/manmade disaster is to provide immediate post-disaster communication links between the disaster victims and some overlay networks. This paper proposes a novel scheme that uses the surviving Mobile handSets (MS) as sensing nodes to form an auto-configured Hierarchical Cognitive Radio Network (H-CRN). The implementation of this H-CRN is explained through detailed problem scenario statement and step-by-step implementation of automatic identification of emergency situation by the MS nodes. An overview of the cross-layer framework used by the MS nodes is also presented. This novel scheme is tested through some hypothesis along with probability calculations for successful identification of emergency situation, formation of ad hoc group and Emergency Beacon Message (EBM) transmission.

Direction finding using a linear three‐element interferometer approach

Results are presented from the operation of a system employing a linear three‐element antenna array to determine the angle of arrival of a radio signal in a low‐angle terrestrial situation. Based on a system successfully employed in determining the direction in space of meteor echoes at elevated angles, accurate direction determination was obtained in three widely varied terrestrial environments. While such a system would be susceptible to strong multipath signals, and therefore unsuitable for congested cellular environments, there are applications, for example emergency beacon location, in which this does not present a significant problem.

Interference in the 121.5/243 MHz SARSAT Frequency Bands

In the SARSAT signal environment it is possible to receive many(5 to 20) simultaneous emergency beacon signals combined with voice and interference of various types, all simultaneously occupying essentially the same frequency-time space. The paper first provides a survey of the different sources of interference which occur in the 100 to 500 MHz frequency band. Then the paper examines those sources of interference which enter the 121.5/243 MHz frequency bands of the SARSAT system.

Emergency beacons for doctors' cars

Emergency beacons for doctors' cars