Communication in the High North: Supporting Safe Maritime Operations

2013 ◽  
Author(s):  
Beate Kvamstad
Keyword(s):  
Communication Systems ◽  
Situational Awareness ◽  
Field Tests ◽  
Satellite Communications ◽  
Satellite System ◽  
The Arctic ◽  
Safety Level ◽  
Communication Infrastructure ◽  
Arctic Conditions ◽  
Maritime Operations

The special Arctic conditions with the presence of ice and harsh weather require complex offshore maritime operations compared to more central parts of the world. In order to maintain the safety level of the operations one need to share information amongst numerous actors across large distances. This is especially important in critical situations, when correct decisions need to be made very fast. Having a shared situational awareness becomes crucial. This again requires reliable and robust communication infrastructure such that undisrupted information is received by the end user in time. This represents a major challenge in the Arctic, since communication infrastructure above 75°N is relatively poor. Ships operating in open seas use maritime communication systems based on geostationary (GEO) satellites which orbit the earth above the equatorial line, such as for example Inmarsat and VSAT. However, they have little or no coverage at all in the Arctic and the low elevation angles makes them vulnerable to external influences. The theoretical coverage limit for GEO systems is 81.3°N, but field tests performed in the Norwegian MarSafe North1 project showed that instability and signal dropouts can be experienced already at 70° N during certain conditions. The only satellite system that provides full coverage in the Arctic area is Iridium, and it offers digital capacity through the Iridium OpenPort services. However, users have reported unstable performance, and the field tests showed that Iridium has unstable digital throughput in Arctic areas. The paper will present results from field tests performed in the MarSafe North project. The projects MarCom2, MarSafe North and ArctiCOM3 have investigated the state-of-the-art of Arctic communications; they have investigated future needs for satellite communications and proposed potential solutions. This paper will present the main results from these projects, as well as describing the main activities and tentative results achieved in the on-going project MARENOR, which analyses the factors that influence the quality of service of navigation and communication systems in the Arctic.

scholarly journals Optical design challenges of subnivean camera trapping under extreme Arctic conditions

2021 ◽  
pp. 1-16
Author(s):  
Anastasiia Pusenkova ◽  
Mathilde Poirier ◽  
Davood Kalhor ◽  
Tigran Galstian ◽  
Gilles Gauthier ◽  
...  
Keyword(s):  
Optical Design ◽  
Electrical Power ◽  
Extreme Environments ◽  
Field Tests ◽  
Camera Traps ◽  
Camera Trapping ◽  
The Arctic ◽  
Direct Observations ◽  
Arctic Regions ◽  
Arctic Conditions

Camera trapping is widely used in different ecological studies and is particularly important for remote locations and extreme environments. However, the application of camera traps in Arctic regions remains very limited. One of the challenges is the formation of hoar on the lens of cameras. In this article, we propose a solution to address this problem by changing the camera parameters and its position in order to optimize the camera trap for long-term subnivean deployment in the Canadian Arctic. Preliminary field tests show that this approach allows tracking lemmings in the frozen environment without natural light or external electrical power supply, where the direct observations are impossible for the most part of the year. We obtained the first videos of lemmings under the snow during the Arctic winter. Extending the observational network of the newly designed camera traps will help to better understand lemming population dynamics. The demonstrated approach is also promising for other polar applications.

System Modeling and Precoding Design for Multi-beam Dual-polarized Satellite MIMO System

2019 ◽  
Vol 13 (4) ◽  
pp. 374-381
Author(s):  
Tao Kai ◽  
Sun Xiaoyun ◽  
Wang Yang ◽  
Jingchun Li
Keyword(s):  
Communication Systems ◽  
Satellite Communication ◽  
Channel Model ◽  
Transmission Rate ◽  
Mimo System ◽  
System Modeling ◽  
Satellite Communications ◽  
Satellite System ◽  
System Capacity ◽  
Dual Polarized

Background: As the multimedia service develops and the transmission rate in terrestrial communication systems increases rapidly, satellite communication needs to improve the transmission rate and throughput. Multiple Input Multiple Output (MIMO) techniques can increase the system capacity significantly by introducing the space dimension, as the system bandwidth remains the same. Therefore, utilization of MIMO for satellite communications to increase the capacity is an important research topic. So MIMO techniques for multibeam satellite communications are researched in the dissertation. Objective: The goal of this work is improving the capacity of the satellite system. Multi-beam and dual-polarized technologies are applied to a satellite system to improve the capacity further. Methods: In this paper, we first introduce a multi-beam dual-polarized satellite multi-put and multiout (MBDP-S-MIMO) system which combines the full frequency multiplexing and dual-polarization technologies. Then the system model and channel model are first constructed. At last, to improve the capacity further, BD and BD-ZF precoding algorithms are applied to MBDP-S-MIMO and their performance is verified by simulation. Results: Simulation results show the performance of the BD precoding algorithm gets better with the growth of the XPD at the receiver and is almost not affected by the growth of the channel polarization correlation coefficient. In addition, with the growth of the users’ speed, the performance becomes worse. Conclusion: The multi-beam dual-polarized satellite MIMO system has high capacity, and it has certain application prospects for satellite communication.

INNOVATIVE METHOD OF SATELLITE COMMUNICATION

2019 ◽  
Author(s):  
Teodor Narytnik ◽  
Vladimir Saiko
Keyword(s):  
Communication Systems ◽  
High Speed ◽  
Satellite Communication ◽  
Radio Channel ◽  
Satellite Communications ◽  
Service Area ◽  
Satellite Systems ◽  
Orbit Satellite ◽  
Geometric Size ◽  
Distributed Satellite

The technical aspects of the main promising projects in the segments of medium and low-orbit satellite communication systems are considered, as well as the project of the domestic low-orbit information and telecommunications system using the terahertz range, which is based on the use of satellite platforms of the micro- and nanosatellite class and the distribution of functional blocks of complex satellite payloads more high-end on multiple functionally related satellites. The proposed system of low-orbit satellite communications represents the groupings of low-orbit spacecraft (LEO-system) with the architecture of a "distributed satellite", which include the groupings of the root (leading) satellites and satellite repeaters (slaves). Root satellites are interconnected in a ring network by high-speed links between the satellites. The geometric size of the “distributed satellite” is the area around the root satellite with a radius of about 1 km. The combination of beams, which are formed by the repeater satellites, make up the service area of the LEO system. The requirements for the integrated service area of the LEO system (geographical service area) determine the requirements for the number of distributed satellites in the system as a whole. In the proposed system to reduce mutual interference between the grouping of the root (leading) satellites and repeater satellites (slaves) and, accordingly, minimizing distortions of the information signal when implementing inter-satellite communication, this line (radio channel) was created in an unlicensed frequency (e.g., in the terahertz 140 GHz) range. In addition, it additionally allows you to minimize the size of the antennas of such a broadband channel and simplify the operation of these satellite systems.

scholarly journals Spectrum Awareness for Cognitive Radios Supported by Radio Environment Maps: Zonal Approach

2021 ◽  
Vol 11 (7) ◽  
pp. 2910
Author(s):  
Paweł Kaniewski ◽  
Janusz Romanik ◽  
Edward Golan ◽  
Krzysztof Zubel
Keyword(s):  
Situational Awareness ◽  
Cognitive Radios ◽  
Field Tests ◽  
Radio Networks ◽  
Map Construction ◽  
Environment Map ◽  
Construction Techniques ◽  
Interpolation Techniques ◽  
Environment Maps ◽  
Radio Environment Maps

In this paper, we present the concept of the Radio Environment Map (REM) designed to ensure electromagnetic situational awareness of cognitive radio networks. The map construction techniques based on spatial statistics are presented. The results of field tests done for Ultra High Frequency (UHF) range with different numbers of sensors are shown. Exemplary maps with selected interpolation techniques are presented. Control points where the signal from licensed users is correctly estimated are identified. Finally, the map quality is assessed, and the most promising interpolation techniques are selected.

scholarly journals Communication infrastructure for situational awareness enhancement in WAMS with optimal PMU placement

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Bhargav Appasani ◽  
Amitkumar Vidyakant Jha ◽  
Sunil Kumar Mishra ◽  
Abu Nasar Ghazali
Keyword(s):  
Real Time ◽  
Situational Awareness ◽  
Area Measurement ◽  
Measurement Unit ◽  
Monitoring And Control ◽  
Communication Infrastructure ◽  
Wide Area Measurement System ◽  
Digital Elevation ◽  
Elevation Model ◽  
And Control

AbstractReal time monitoring and control of a modern power system has achieved significant development since the incorporation of the phasor measurement unit (PMU). Due to the time-synchronized capabilities, PMU has increased the situational awareness (SA) in a wide area measurement system (WAMS). Operator SA depends on the data pertaining to the real-time health of the grid. This is measured by PMUs and is accessible for data analytics at the data monitoring station referred to as the phasor data concentrator (PDC). Availability of the communication system and communication delay are two of the decisive factors governing the operator SA. This paper presents a pragmatic metric to assess the operator SA and ensure optimal locations for the placement of PMUs, PDC, and the underlying communication infrastructure to increase the efficacy of operator SA. The uses of digital elevation model (DEM) data of the surface topography to determine the optimal locations for the placement of the PMU, and the microwave technology for communicating synchrophasor data is another important contribution carried out in this paper. The practical power grid system of Bihar in India is considered as a case study, and extensive simulation results and analysis are presented for validating the proposed methodology.

scholarly journals Communications satellites in Canadian security policy: History and prospects

2021 ◽  
pp. 002070202110164
Author(s):  
Elinor Sloan
Keyword(s):  
Security Policy ◽  
Final Section ◽  
Canadian Arctic ◽  
Satellite Communications ◽  
Satellite System ◽  
Gulf War ◽  
Low Earth Orbit ◽  
Policy History ◽  
Security Environment ◽  
Communications Satellites

This article traces Canada’s early interest in space, before turning to its late 1960s decision to focus on a domestic, commercial/civilian communications satellite system in geostationary orbit and the subsequent decline in Canada’s military space efforts. It then highlights the wake-up call of the 1991 Gulf War, which demonstrated the critical importance of military communications satellites to future operations, and the steps Canada has taken to gain assured access to such satellites in the decades since. The final section outlines recent advances in low Earth orbit satellite communications (LEO satcom) and the ways in which these systems can address shortfalls in their geostationary cousins. Drawing reference to a new international security environment, it concludes that Canada should move expeditiously to incorporate LEO satcom into efforts to address the growing imperative of military satellite communications in the Canadian Arctic.

scholarly journals Wave measurements on sea ice: developments in instrumentation

2006 ◽  
Vol 44 ◽  
pp. 108-112 ◽  
Author(s):  
M.J. Doble ◽  
D.J.L. Mercer ◽  
D.T. Meldrum ◽  
O.C. Peppe
Keyword(s):  
Satellite Communications ◽  
Weddell Sea ◽  
Data Recovery ◽  
The Arctic ◽  
Polar Regions ◽  
Constant Attention ◽  
Wave Measurements ◽  
Wire Strain ◽  
Propagation Of Waves ◽  
Communications System

AbstractTraditional methods of measuring the propagation of waves originating from ocean swell and other sources have relied on wire strain gauges, accelerometers or tiltmeters. All methods required constant attention to keep in range, while data recovery has demanded that the instrument site be revisited. In this paper, we describe the use of ultra-sensitive tiltmeters and novel re-zeroing techniques to autonomously gather wave data from both polar regions. A key feature of our deployments has been the use of the Iridium satellite communications system as a way of ensuring continuous data recovery and remote control of the instrumentation. Currently four instruments have been successfully reporting from the Arctic Ocean for over 18 months, with two further units deployed in 2005, one in the Weddell Sea, Antarctica, and one additional unit in the Arctic.

Access Control Algorithm with Limited Power Constraint for Mobile Satellite Communications

2014 ◽  
Vol 548-549 ◽  
pp. 1286-1289
Author(s):  
Ya Zhe Gao ◽  
Xiao Han Xia ◽  
Zi Ming Su ◽  
Xi Luan ◽  
Jian Jun Wu
Keyword(s):  
Admission Control ◽  
Control Algorithm ◽  
Load Capacity ◽  
Satellite Communications ◽  
Satellite System ◽  
Power Constraint ◽  
Priority Service ◽  
Limited Power ◽  
Mobile Satellite ◽  
Service Priority

The problem of admission control caused by the limitation of resource in hotspot beams in satellite system is considered in this paper. Based on the idea of borrowing resources from surrounding beams, we give a scheme that the beam reserve resources is borrowed proportionally. After that, the original admission control algorithm based on service priority is modified in order to protect access rate of the low priority service. Simulation results prove that the proved scheme can increases the available beam load capacity effectively and provide a guarantee for the access of those services with low priority.

On the Problems of SLAM Simulation for Mobile Robots in the Arctic Conditions

2020 ◽  
pp. 34-44
Author(s):  
Elvira Chebotareva ◽  
Tatyana Tsoy ◽  
Bulat Abbyasov ◽  
Jamila Mustafina ◽  
Edgar A. Martinez-Garcia ◽  
...  
Keyword(s):  
Mobile Robots ◽  
The Arctic ◽  
Arctic Conditions
Sign in / Sign up

Export Citation Format

Share Document