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1 INTRODUCTION

After the Soviet Union launched the first in the world

artificial satellite, Sputnik 1, satellite systems became

the delivery mode of choice for communication

positioning information with developments of first

Global Navigation Satellite Systems (GNSS). The US

military system Transit started with development

from 1960 and the Soviet Union military system

Cicada was established in 1974. After early

experimentation with the doomed Transit and Cicada

systems, remember having to wait hours for the next

satellite to appear overhead, new GNSS of GPS and

GLONASS were created at the end of 20th Century to

offer highly accurate global satellite positioning

system in longitude and latitude, almost anytime and

anywhere in the world.

The Transit system was switched off in 1996 to

2000 after more than 30 years of reliable service. By

then, the US Department of Defence was fully

converted to the new GPS network. The GPS service

could not have the market to itself, the ex-Soviet

Union (Russia) developed a similar system called

GLONASS in 1988 and ceased the previous Cicada

system. The Transit or Cicada systems, provided

intermittent two-dimensional (latitude and longitude)

position fixes every 90 minutes on average and were

the best suited to marine navigation, The GPS or

GLONASS GNSS-1 satellite networks provide

continuous position and speed in all three dimensions

(latitude, longitude, and altitude), equally effective for

navigation and tracking at sea, on land and in the air,

which space, users and ground segments are shown

in Figure 1.

In the meantime, China started development own

GNSS-2 navigation system known as Compass

(BeiDou), which is regionally operational. The BeiDou

GNSS network consists of two separate satellite

Architecture of Positioning and Tracking Solutions for

Maritime Applications

D.S. Ilcev

University of Johannesburg (UJ), Johannesburg, South Africa

ABSTRACT: This paper discusses the current and new satellite transponders for global tracking and detecting

of oceangoing ships, assets, crew, passengers and any moving objects at sea for enhanced vessels traffic control

and management. These transponders are able to monitor all maritime assets and to improve safety, security of

movements and collision avoidance, especially during very bad weather conditions and visibility. By

deployment of the Global Navigation Satellite System (GNSS) in integration with Inmarsat, Iridium and other

satellite systems in one unit with antenna, it is possible to provide reliable positioning and tracking solutions for

civilian maritime, other mobiles and personnel at different Radio Frequency (RF) bands. The existing and

forthcoming space and ground segment for positioning and tracking solutions as a modern Satellite Asset

Tracking (SAT) onboard ships, and other relating systems are discussed and benefits of these new technologies

and solution for improved positioning and tracking are explored.

http://www.transnav.eu

the International Journal

on Marine Navigation

and Safety of Sea Transportation

Volume 16

Number 3

September 2022

DOI: 10.12716/1001.16.03.09

482

constellations that have been operating since 2000 and

a full-scale global system is currently under

construction. However, the second GNSS-2 satellite

network still in development stage is the European

Galileo.

Figure 1. Military GNSS-1 Network – Source: Ilcev

Figure 2. Marisat Space and Ground Segments – Source:

Ilcev

The US GPS and Russian GLONASS as GNSS-1

satellite positioning networks, all-weather spacecraft,

full jam resistant and continuous operation navigation

system, utilize precise range measurements of

Position, Velocity and Time (PVT), call sign of ship

and ID data anywhere in the world. This GNSS

system provides military and commercial maritime,

land and aeronautical users via Medium Earth Orbits

(MEO) satellites with highly accurate worldwide

three-dimensional, common-grid, position and

location data, velocity and precise timing to accuracies

that have not previously been easily attainable. The

GNSS service is based on the concept of triangulation

from known points similar to the technique of

“resection” used with a map and compass, except that

it is done with radio signals transmitted by satellites.

The GNSS receiver must determine when a signal is

sent and the time it is received. Nothing except

onboard ships and other mobiles GNSS receivers is

needed to use the system free of charge, which does

not transmit any signals and therefore they are not

electronically detectable [01, 02, 03].

Most communications between ships or other

mobiles and traffic controllers are still conducted via

VHF, UHF and HF analog and digital voice or

radiotelephone RF-bands, known as Mobile Radio

Communications (MRC) system. However, in some

busy portions of the world this system is reaching its

limit, the RF-bands are congested and additional

frequencies are not available. These disadvantages

limit the growth in the traffic to those ships or mobiles

that can be safely handled. Thus, to improve the

communication and traffic control facilities of all

maritije and mobile users almost 40 years ago was

implemented civilian Mobile Satellite Communication

(MSC) system, which takes less time, reduced

interference and can handle more information than

MRC system alone.

Before that, the World’s first military maritime

MSC system “Marisat” was unveiled in 1976 by the

US Comsat General with only three satellites and

networks in the Atlantic, Pacific and Indian oceans. In

Figure 2 is shown Military Satellite Communication

Network for navy, ground and air forces using

L/C/Ka-band, which can provide MSC service via

current Geostationary Earth Orbits (GEO), MEO or

Low Earth Orbits (LEO) satellite constellations. Thus,

modern military satellite communications can

additionally use UHF, S, X and Ku-band between

Mobile Earth Stations (MES) and Military Control

Centre. The MSC systems are not designed only to

provide more cost effective, reliable, redundant and

fastest communication links between ships and traffic

controllers, but also to integrate GNSS data for

implementing new service for enhanced tracking,

navigation, surveillance and tracking solutions. The

convergence of MSC and Internet transmission

technique has opened many opportunities to provide

positioning and tracking data to the ground

infrastructure and for implementation new

Communication, Navigation and Surveillance (CNS).

With the need for increased bandwidth capability, the

numbers of new GEO and Non-GEO satellites is

increasing dramatically. The size of the Earth requires

multiple or some hybrid satellites to be placed in orbit

constellation to cover areas of interest and adequate

communications coverage [3, 4, 5].

2 GLOBAL S ATELLITE ASSET TRACKING (SAT)

SYSTEMS

The GNSS network is represented by fundamental

solutions for PVT, identification and other data of the

US GPS and Russian GLONASS military satellite

systems, which suffer from particular weaknesses that

render them unsuitable for use in modern

transportation state affairs as sole solutions for

positioning, tracking and detecting of of ships and

other mobile assets. A major goal of the near-

universal use of GNSS systems is their integration

with maritime and other MSC systems, which very

small GNSS/Satellite units will be able to improve

positioning, detecting and tracking facilities of ships,

crew, passengers and other mobile, such as ground

vehicles and aircraft.

Figure 3. Configuration of SAT System – Source: Inmarsat

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As a result of these significant efforts, new

positioning, detecting and tracking technologies have

been projected and developed to utilize modern space

(radio and satellite) Communication, Navigation and

Surveillance (CNS) solutions and services for

enhanced traffic control, monitoring, and

management of civilian and military mobile personal

and assets. Received tracking data by GPS/GLONASS

Receiver (Rx) onboard oceangoing ships and other

offshore objects can be sent via Inmarsat GEO or

Iridium Non-GEO spacecraft, Ground Earth Stations

(GES) terminals and Internet to the Control Centres

and Operations Control. In fact, all ships and crew

require far more sophisticated service from modern

satellite tracking systems than standalone GPS or

GLONAS positioning systems in disress and Search

and Rescue (SAR).

In fact, it is proposed Satellite Asset Tracking

(SAT) system as integrated configuration in one

Satellite Tracking Unit (STU) containing very small

GPS or GLONASS receivers integrated with miniature

GEO and Non-GEO satellite transceivers with both

adequate antennas in one radome. The configuration

of SAT infrastructure for civilian applications is

illustrated in Figure 3, which integration is deploying

the GNSS subsystem of US GPS and Russian

GLONASS to provide free of charge PTV and other

data to oceangoing ships an d all mobiles in seaport

area. This PTV and other data can receive ships and

vehicles, such as trucks and railcars and ships via

onboard GPS/GLONASS Rx integrated with satellite

transceiver [4, 5, 6].

The SAT satellite transponder will provide

solutions for the global identification and tracking of

all type of vessels and crew, such as cargo ships and

containers, and including land vehicles and aircraft.

As shown in Figure 4, the SAT onboard equipment

receives GNSS signals from GPS or GLONASS

spacecraft (1) and sends PTV tracking messages of

position (2) via GEO satellite to GES (3) of Satellite

Application Service Providers, Terrestrial

Telecommunication Network (TTN) and Internet, to

the receiver and processor of Tracking Control

Stations (TCS) infrastructure (4). Thus, the

positioning, communication tracking lines are

highlighted in black, while all opposite lines

highlighted in red are indicating SAT receiving

process, namely, the receiver of onboard ships and

other mobiles SAT terminals are receiving PVT and

other data from TCS useful for collision avoidance

and showing it on receiver display.

Figure 4. Configuration of SAT Network – Source: Ilcev

Figure 5. Inmarsat Maritime and other Mobile Satellite

Network – Source: Ilcev

As already stated, then the Satellite Transceiver

(Rx/Tx) is providing frequently transmissions of PTV

and other data via GEO or Non-GEO spacecraft

through GES or Gateway terminals and Internet to the

Control and Operations Centres. Because of many

incidents in past time, without successful search,

detecting and tracing of oceangoing ships

disappeared in some disasters caused by collision or

grounding, were proposed new positioning and

tracking and detecting solutions via SAT onboard

devices and ground facilities. Thus, if SAT

transponder was fixed onboard Air France or

Malaysian aircraft crashed in 2009 and 2014,

respectively, SAR forces should find the wreck in 1-2

days and in area of maximum 100 to 200 miles.

At present only the following mobile satellite

operators are providing global or near-global satellite

constellations for civilian and military SAT service: (1)

Inmarsat GEO near-global satellite network

provides coverage up to 800 North and South; (2)

O3b MEO satellite network provides near-global

global coverage up to 500 North and South; (3)

Iridium Big LEO satellite network provides only real

complete global coverage, because of intersatellite

links; (4) Globalstar Big LEO satellite network with

limited coverage that is depending on distributed

number of Gateways; and (5) Orbcomm Little LEO

global satellite network with limited coverage

depending on distributed number of Gateways.

The problem of current satellite fixed and mobile

operators is that they are providing service via GEO

satellite constellations and in this case are not able to

cover both polar areas, such as Inmarsat, Eutelsat and

Intelsat. To realize a real global coverage will be

necessary to implement Hybrid Satellite Orbits (HSO)

combined between Inmarsat, O3b, Globalstar and

Orbcomm High Elliptical Orbit (HEO), such as

Russian Molniya satellite constellations [1, 4, 5, 6, 7].

3 INMARSAT MSC NETWORK AND EQUIPMENT

Inmarsat was established as not-for-profit company in

1979 as the International Maritime Satellite

Organization (Inmarsat) set up at the behest of the

International Maritime Organization (IMO) and

United Nations (UN), with its headquarter office in

London. Initially was developed for the purpose of

establishing a maritime satellite communications

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network for commerical, cprporate and safety

applications. It began trading in 1982 via GEO satellite

constellation for oceangoing ships and searigs

providing coverage up to 800 North and 800 South.

Afterwards Inmarsat started with development

service for land (road and rail), personal (handheld),

transportable and aeronautical applications. The

current Inmarsat-4 is providing service at the

following RF bands: 1.6/1.5 GHz of L-band (Service

Link) and at 6.4/3.6 GHz of C-band (Feeder Link) .

In 2016, the fourth generation of Inmarsat-4

satellite constellation is upgraded with fifth

generation of Inmarsat-5 satellite constellation, which

maritime and other MSC networks operate via L, C

and Ka-band, which maritime and other mobile

satellite network is shown in Figure 5. The current

Inmarsat network provides comercial mobile service

via Land Earth Stations (LES) and Inmarsat satellites

for Ship Earth Stations (SES), Vehicle Earth Stations

(VES), Aeronautical Earth Station (AES),

Transportable Earth Station (TES), Personal Earth

Station (PES) terminals.

Figure 6. Maritime Sailor Inmarsat-C and mini-C Terminals

– Source: Inmarsat

The emergency and distress service is provided via

special Rescue Coordination Centres (RCC). Entire

Inmarsat network is managed by Network Control

Centre (NCC) in London, Network Coordination

Stations (NCS), Network Operations Centre (NOC),

and Telemetry, Tracking and Command (TT&C).

The sixth generation of Inmarsat network known

as Global Express GX) developed by Boeing for about

$1.2 billion will include a new plans for the Orchestra

satellite network roadmap, which currently includes

seven satellites over the next three years to provide

additional L and K-band capacity for Fleet GX users.

Five of those satellites will operate in GEO orbit, with

two being placed in Highly Elliptical Orbits (HEO) to

provide polar coverage on the network for the first

time. In addition, Orchestra will bring together

existing GEO satellites with new LEO and terrestrial

5G into an integrated solution for about $3 billion.

The Inmarsat I-4 and I-5 satellite constellations are

providing Global Ship Tracking (GST) service for

maritime applications onboard seagoing or inland

vessels are providing IsatData Pro, IsatM2M,

Inmarsat-C, mini-C, FleetPhone and old Standard-D

devices. The ground segment comprises a network of

LES terminals managed by LES operators. However,

the major part of the ground segment and network for

maritime applications are SES terminals as mobile

subscribers. Each LES operator provides a

transmission link between satellite network and TTN,

capable of handling many types of calls to and from

MES terminals simultaneously over the Inmarsat

networks [03, 04, 05, 08].

3.1 Inmarsat-C and mini-C Terminals

The Inmarsat-C and mini-C standards are a two-way

packet data small satellite terminals dedicated for

installation onboard ships or other mobiles for

transmission of two-way data and telex messages at

an information rate of 600 b/sec on L-band. These

messages are transmitted only in ship-to-shore

direction via LES terminals, TTN and Internet to PC

terminals with special software to bi processed and

memorised, which PVT data can be used for tracking

of ships and any other mobiles.

Inmarsat standard-C is developed in 1988 for

commercial and distress application for merchant

fleets. The typical SES-C has a small and compact

omnidirectional antenna in radome as an Above Deck

Equipment (ADE), which can be easily mounted on all

type of ships, yachts, fishing boats, offshore rigs and

other mobiles. The main components of Standard-C

terminal shown in Figure 6 (Left) contains ADE and

Below Deck Equipment (BDE) with peripherals. The

ADE can be a single Inmarsat-C or combined

Inmarsat-C with GPS omnidirectional antenna. The

BDE component can be an Inmarsat/C transceiver

only or combined with a built-in GPS receiver

installed in the radio station or on the navigating

bridge interfaced to messaging unit, printer and

distress button with signalling box. Some SES-C has

built-in message preparation and display facilities and

others have a standard RS-232 port so that users can

connect their PC or other data equipment. This

standard provides data, E-mail, position reporting

and polling, Fax, Tlx, X.25, inters-hip communication,

Supervisory Control and Data Acquisition (SCADA)

or Machine-to Machine (M2M), etc.

The Inmarsat mini-C terminal was introduced in

2002 as smallest and very compact ships Inmarsat

satellite communication transceiver integrated with 2-

channel GPS Rx in one single device, with a total with

of 1.1 kg and a size of 15 cm, which is depicted in

Figure 6 (Right). The mini-C unit provides the same

service as Inmarsat-C, and both can be deployed as

ships solutions for Global Maritime distress and

Safety System (GMDSS), Long Range Identification

and Tracking (LRIT), and Vessel Monitoring System

(VMS). The power requirements of both terminals can

be met from a ship’s mains or via battery sources via

power supply unit with rechargeable facilities, (03, 04,

09].

Figure 7. Maritime Inmarsat-D+ Generations – Source:

Orbcomm

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3.2 Inmarsat-D/D+ and Inmarsat-IDP Terminals

Inmarsat-D introduced in 1997 offers global one-way

(simplex) and Inmarsat-D+ two-way (duplex) data

communications utilizing equipment no bigger than a

personal CD player, which 1st and 2nd generations

respectively are shown in Figure 7.

These units are integration of a Standard D+

transceiver with the US GPS or Russian GLONASS

receivers and both antennas. It is ideally suited for

ships and mobile tracking, short data messaging,

SCADA (M2M), broadcast of information, financial

data, stock exchange, and many other data. These

terminals can store and display at least 40 messages of

up to 128 characters each, and will also be able to

transmit PVT data derived from integrated GPS or

GLONASS receivers. All messages sent to SES will be

numbered to enable the subscriber to identify any lost

messages. Repeated messages will be sent with the

same message number to allow repeated call

indication. The Inamrsat D+ standard equipment is

capable to transmit from ships subscribers to base

stations: a) Acknowledgement Burst, b) Short Burst

Data (SBD) and c) Long Burst Data (LBD).

Due to the development of the new Inmarsat

IsatData Pro and IsatM2M standards, as of 31

December 2015, new Inmarsat-D + activations have

been suspended. Alternatively, Inmarsat offers a new

generation of similar telematics known as IsatData

Pro and IsatM2M satellite terminals, which are fully

programmable and environmentally sealed, use the

global two-way Inmarsat Isat satellite service

integrated with GPS or GLONASS data for remotely

managing fixed and mobile assets. These equipment,

whether used for oceangoing ships, fishing vessels,

buoys, containers, vehicle tracking, SCADA (M2M) or

oil and gas equipment, these standards facilitates

improved asset tracking and fleet management in

lower operating costs and regulatory compliance.

1. IsatData Pro – This standard is a global two-way

packet data service for M2M that enables

companies to track and monitor their fixed or

mobile assets, giving them increased visibility of

business operations, enhanced efficiency, and

greater safety and security for their assets, cargo

and drivers, while lowering operational costs. It

sends 6,400 bytes and receives 10,000 bytes, with a

latency of 15 to 60 seconds depending on the size

of the message.

2. IsatM2M – This standard is global, store-and-

forward low data rate messaging (SBD) to and

from remote assets for tracking, monitoring and

control operations. It supports critical applications

such as ships and other mobile tracking and

monitoring system at speed rate of 10.5 or 25.5

bytes in the transmit direction and 100 bytes in the

receive direction, with a latency typically between

30 to 60 seconds. The Inmarsat IDP-690 terminal

shown in Figure 8 (Left) is part of the IDP 600

series of terminals for vessel tracking device, while

in Figure 8 (Right) is the IDP-800 dedicated to

monitor trailers, containers, and vessels.

Figure 8. Maritime Inmarsat-IDP new Generations – Source:

Orbcomm

Figure 9. Thrane&Thrane Message Terminal & Capsat

Printer – Source: Cobham

Thus, Inmarsat-IDP terminals with their serial

interface and published communication protocol

enable easy integration with an external controller,

mobile display terminal or PC (Laptop) terminal. If

there is not enough space for a laptop or PC, both

Inmarsat-IDP terminals can be interfaced to small

message terminal shown in Figure 9 (Left) with a key

board and a very small printer shown in Figure 9

(Right) [5, 10, 11, 12, 13].

4 IRIDIUM MSC NETWORK AND EQUIPMENT

The concept for the Iridium MSC system was

proposed by Motorola engineers in late 1989 and after

a phase of research, the Iridium LLC satellite system

was founded in 1991, with an investment of about $7

billion. Maintaining its leadership, Iridium LLC

became operational MSC system on 1st November

1998. After a period of bankruptcy, the Iridium service

was relaunched on March 28, 2001. The Iridium Big

LEO satellites are situated in a near-polar orbit at an

altitude of 780 km. They circle the Earth once every

100 minutes travelling at a rate of about 26,856 km/h.

Each satellite is cross-linked via intersatellite links to

four other satellites, with two satellites in the same

orbital plane and two in the adjacent plane.

The Iridium satellite constellation consists in 66

operational satellites and 14 spares once orbiting in

the satellite constellation of six polar planes. The

Iridium system provides true global coverage and

roaming globally over 48 spot overlapping beams,

and the diameter of each spot is about 600 km.

Iridium as a true global operator provides voice and

data service including SAT for ships and all mobile

applications via uplink/downlink at 1621.35-1626.5

MHz, feeder links at 29.129.3 GHz of Ka-band

(uplink) and at: 19.4-19.6 GHz of K-band (downlink)

and cross-link or intersatellite link at 23.1823.38 GHz

of Ka-band.

The current Iridium network shown in Figure 10

provides maritime and other mobile service via

Ground Earth Stations (GES) and Iridium LEO

satellites connecting SES, VES, AES, PES as handhelds

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and semi-fixed terminals with Public Switched

Telephone Network (PSTN) ground network. The

PSTN switch system is connected to a Public

Network, a Private Network, a Cellular Network, and

a terrestrial Wireline Network.

Figure 10. Iridium MSC Network – Source: Ilcev

Figure 11. Iridium Miniature SAT Terminals – Source:

Iridium

The Entire Iridium network is managed by the

System Control Segment (SCS), which consists of

three main components: four Telemetry Tracking and

Control sites, the Operational Support Network, and

the Satellite Network Operation Centre. The SCS

ground network is what commands and controls the

satellites for the Iridium system. It provides global

operational support and control services for the

satellite constellation. It also delivers satellite tracking

data to the Gateways [1, 5, 14].

4.1 Iridium MSC and Fleet Management Terminals

The Online Tracking Platform (OTP) system is a Web

based integrated Iridium, Inmarsat and Global System

for Mobile Communications (GSM) or cellular system

tracking solution, which is compatible with modern

Web browsers and works on a multilingual platform

and displays and manages them in a single unified

interface. With OTP, asset locations and movements,

including position, speed, altitude and heading are

tracked in real-time worldwide via GPS updates. This

system may be integrated GSM and satellite tracking

in one solution which via Web provides superior GPS

tracking and mapping, no special hardware or

software is required, seamless software and firmware

updates, reliably tracks personnel, equipment, ships

or vehicles, anywhere in the world. On the other

hand, some trackers may use adequate software and

not OTP system.

1. Quake 9602 Mini Tracker – The 9602 is a short-burst

data transceiver designed for use as a basic unit for

many tracking devices using the Iridium Network,

illustrated in Figure 11 (Left). This very tiny,

41x45x13 mm and 27.22 grams, two-way

transceiver is perfect for use in a variety of

applications for fast-growing mobile devices,

including remote tracking of aircraft and real

estate and M2M tracking solutions. This Iridium

unit does not have a GPS Rx, but can be connected

to the built-in GPS via input/output ports. In

addition, appropriate sensors can be connected to

the inputs of this device, such as mileage, fuel

consumption, temperature, doors, cargo etc.

2. Iridium SL Mini Tracker – Iridium very small and

lightweight SBD modem with integrated GPS Rx is

the smallest self contained Iridium tracker in the

world, which 32 bit Advanced RISC Machine

(ARM) processor supported by a fully user

customizable LUA scripting language, where RISC

is Reduced Instruction Set Computing. Its internal

dimensions 1.77 x 1.77 x 1.34 inches (45 x 45 x

34mm), including the battery, which modem and

antenna are illustrated in Fig. 11 (Middle). It can

transmit the location from anywhere in the world

and is built on the latest satellite, antenna and

electronics technology tfor tracking and

monitoring all mobiles in real time, the actual size

of which is shown in Figure 11 (Right).

3. Quake Q4000 Tracker – The Iridium Q4000i tracker

manufactured by the American company Quake is

small enough to fit in your hand. It is a two-way

rugged transponder that can combines dual-mode

operability over Iridium satellite and GSM

terrestrial networks with GPS into a versatile, all-

in-one mobile asset tracking solution, illustrated in

Figure 12 (Left). Quake is also supplying the

same Q4000 modem that can be optionally used

for service over Inmarsat, Globalstar and

Orbcomm integrated with 50 channels of GPS Rx

and with optional GSM cellular service.

Figure 12. Iridium Mobile SAT Terminals with Antenna –

Source: Quake

Figure 13. Iridium Personal Satellite Trackers – Source:

Iridium

Technically, this is am SBD transceiver designed

for use as a base unit for many mobile trackers

487

using the Iridium network, such as oceangoing

ships and container tracking, as well as for

tracking land vehicles and aircraft. In addition,

this equipment without integrated GPS can be

implemented for monitoring of many machines,

pipelines, devices, instruments, power stations and

so on over the SCADA (M2M) network. This unit

provides the following interfaces: 3 serial RS-232C,

J1939 can bus, input/output 2 analog inputs, 8

digital GPIO and digital outputs (relay). Its

dimensions are size: 3.91”x 2.52”x .63” (99.3mm x

64mm x 15.9mm) and weight is 375lbs (170 grams).

In Figure 12 (Middle) is shown bolt, magneting or

adhesive mount Hirschmann low profile Iridium

antenna (63x63x18mm) for Iridium/GPS/3G/GSM

WLAN and other mobile applications, which can

be used for Q4000i and other satellite trackers

onboard all mobiles.

4. Quake Q-Pro Multipurpose Tracker – This unit is

small (119.2x119.4x57.6 mm and 390.6 grams) and

rugged, environmentally-sealed multi-satellite

GPS integrated with Iridium, Globalstar,

Orbcomm and GSM modem with many options,

shown in Figure 12 (Right). For SAT applications

this unit has an integrated GPS receiver with 50

channels and can also be connected to Hirschmann

low profile Iridium antenna, shown in Figure 12

(Middle) [5, 14, 15].

4.2 Personal Satellite Trackers

The following Iridium personal satellite trackers are

ideal units for tracking of passengers and crew after

grounding or in emergency situation with absence of

any luck in distress communications:

1. E-Track Epsilon Personal Tracker – This personal

tracker is a waterproof satellite messaging and

personal tracking device, which provides

autonomous and global real-time coverage, shown

in Figure 13 (Left). Developed around 9602

Iridium modem, it benefits from the latest

developments in satellite technology of GPS and is

IP67. The unit provides two-way texts messaging,

predefined and free-text “HELP” key to send a

distress message with accurate GPS position of the

incident.

2. GeoPro Personal Messenger – This personal tracker

is a solution for remote workforce security,

location awareness and a two-way solution for

exchanging personal messages,, shown in Figure

13 (Middle). When work takes staff off the grid

they often have no reliable means of maintaining

communication. It is an affordable and rugged

device supporting global two-way text messaging

and can be used in one hand with a non-slip

network of factors using a joystick to navigate

through on-screen menus and the keyboard.

3. NANO Personal Tracker – This unit has an ultra-

low power consumption of less than 35μA during

sleep, shown in Figure 13 (Right). This pocketsize

and self-contained personal satellite tracker

provides 256-bit transmit and receive encryption,

precise GPS positioning, real-time reporting and

truly global coverage via the following features: (1)

Power/Enter turns the device ON/OFF and selects

highlighted item on the menu; (2) The

Up/Down/Right Arrow navigates the cursor; (3)

The Check-In Soft Key is accessing Check-In

feature; (4) The Way Point Soft Key is used for

Way Point functions; (5) The USB Port is serving to

charge the battery and connects the PC; (6) The

Emergency key may send an emergency alert,

distress and notification to the search and rescue

(SAR) forces; (7) The Guard button protects the

emergency button from accidentall activation; (8)

The LED unit displays tracking and emergency

statuses; 9. The Antenna post shows the GPS

antenna; and (10) The Antenna post shows the

Iridium antenna [3, 5, 14].

5 GLOBALSTAR MSC DATA NETWORK AND

EQUIPMENT

The American company Loral Space &

Communications, together with Qualcomm

Incorporation, developed the concept of the

Globalstar system at a similar time as Iridium.

Globalstar received a license to operate from the USA

Federal Communications Commission (FCC) in

November 1996. In May 1998, the first launch of four

Globalstar satellites took place, and therefore its space

segment consists of 48 Big LEO spacecraft.

Figure 14. Globalstar MSC Network – Source: Globalstar

In fact, Globalstar does not have an inter-satellite

connection and thus needs a large number of GES

terminals around the world, the spacee, ground and

user network of which is shown in Figure 14. The

current Globalstar network controled by the

Operations Control Centre (OCC) provides maritime

and other mobile service via GES and LEO satellites

connecting SES, VES, AES, PES as handhelds and

semi-fixed terminals with PSTN and other ground

networks

The Globalstar satellite operator is providing

service for users via satellite at 1.610-1.621 GHz

(uplink) and at 2.483-2.500 GHz (downlink) and from

satellite to GES at 5.091-7.055 GHz (feeder link).

Globalstar equipment such as Axonn mobile satellite

tracker devices are designated for asset tracking of

ships and other mobiles such as land vehicles, trains,

containers, and trailers, but with simply modification

of GPS Rx can be used for aircraft tracking as well.

Here will be introduced 2 simplex and 1 duplex

488

Globalstar mobile satellite trackers manufactured by

Axonn company:

1. Simplex AxTracker – This unit provides a battery-

operated, self-contained SAT transmitting PVT

data only (simplex) device, delivered complete and

ready-to-go with no need for an external antenna

or power source, which is shown in Figure 15

(Left). It measures 9.25x6.25x1and is ideal to

operate in hazardous environments, such as ships

container, because can work independently of

power source and any inspection. The units can be

pre-programmed according to the requirements

and to send GPS location and other information at

predefined intervals.

2. Simplex Axonn SMARTONE Tracker – This GPS

Rx/satellite Tx mobile traking device is designed

for the intelligent tracking and management of

powered and non-powered movable assets, and is

a practical solution to improve operating efficiency

and security, which is illustrated in Figure 15

(Middle). The design of this unit allows it to be

easily installed and field managed without the

need for harnesses, antennas and external power.

The advantages of independent power supply, this

unit can work and send position data even if ships

is emergency grounded or a missing ships

container without any power sources. The

SMARTONE device is powered by 4 AA 1.5 V

lithium batteries providing 3+ years of battery life

and removes the need to purchase expensive

proprietary batteries for replacement.

Figure 15. Globalstar Simplex and Duplex Satellite Trackers

– Source: Globalstar

Figure 16. Orbcomm Satellite AIS (S-AIS) – Source:

Orbcomm

3. Duplex Spot Satellite Personal Tracker (Spot 1) –

The Spot Personal Tracker or Spot 1 was

introduced to the market by Axonn in early 2008,

shown in Figure 15 (Right). Using Spot Tracker,

people in emergency and their families ones have

peace of mind knowing help is always within

reach. It is using the GPS Rx to acquire its

coordinates, and then sending its location with a

link to Google maps and a pre-programmed

message via a satellite network. This unit does

more than just call for help and checking

emergency progress, non-emergency assistance are

also available, just by pressing a button. Spot

features four key functions that enable users to

send messages to friends or family, based upon

varying levels of need [5, 15, 16, 17].

6 ORBCOMM MSC EQUIPMENT AND DATA

NETWORK

The Orbcomm MSC system is a wide area packet

switched and two-way data transfer network that

provides GPS/Orbcomm Satellite tracking,

determination and monitoring services via similar

SAT devices shown in Figure 12. This system may

also provide Satellite Automoatic Identification

System (S-AIS) integrated with Radio AIS (R-AIS) for

tracking, monitoring and determination of

maritime and other mobile assets via 36 Orbcomm

Little LEO satellites, whichn space, ground and user

network is shown in Figure 16.

Except S-AIS service, Orcomm also provides SAT

for oceangoing ships onboard broadcast system that

transmitted ship identification, PVT and other critical

data received from GES can be used to assist in

navigation and improve maritime safety and security

at sea. Most current terrestrial-based Radio AIS (R-

AIS) system is already implemented by IMO and

provides only VHF limited coverage nearby

shorelines via Base Stations (BS) and not able to

provide global coverage. The Orbcomm system

overcomes many of these issues thanks to a fully S-

AIS and SAT data service, which is able to monitor

vessels well beyond coastal regions and horizon in a

cost-effective and timely fashion and send this data

via GES to the Coastal Surveillance Centre (CSC) or

Tracking Control Station (TCS). To spread R-AIS

coverage globally some institutions and companies

olso started with development S-AIS [5, 18, 19, 20].

7 CONCLUSION

Mobile SAT networks and solutions for maritime and

all mobile applications that can be used for both

civilian and military applications are described. SAT

mobile networks can operate anywhere in the world,

providing services across the horizon to ships,

vehicles, planes and people on the move. Tracking

messages are transmitted via the above-mentioned

commercial satellites in near real time and space,

whose mobile locations are displayed on computers

with maps of the Geographic Information System

(GIS). Thus, SAT networks and transponders operate

through various existing GEO or non-GEO satellite

constellations, and some of them are designed to

automatically switch from one satellite system to

another, depending on the situation on earth. In fact,

some of the SAT terminals are designed to operate

over 2 or 3 satellite operators, such as Inmarsat,

489

Iridium, Globalstar and Orbcomm. Otherwise, all

messages are encrypted from end to end, including

the addresses of the sender and recipient for

information security purposes. The future of mobile

SAT and communication, navigation and surveillance

(CNS) in general will be a combination of GEO, LEO

and other orbits, such as MEO and HEO or Molny

orbit in so-called hybrid satellite orbits (HSO), which

can provide reliable service globally level even across

the North Pole.

REFERENCES

[1] Ilcev D. S., Satellite Asset Tracking (SAT), CNS Systems

Durban, South Africa, 2015.

[2] Prasad R. and Ruggieri M., Applied Satellite Navigation

Using GPS, GALILEO, and Augmentation Systems,

Artech House, Boston, US, 2005.

[3] Ilcev D. S., Global Aeronautical Communications,

Navigation and Surveillance (CNS) - Theory and

Applications, AIAA, Reston, Virginia, 2013.

[4] Inmarsat Web Sites: Available from:

<www.inmarsat.com>.

[5] Ilcev D. S., Global Mobile Satellite Communications for

Maritime, Land and Aeronautical Applications -

Theory and Applications, Springer, Boston, 2017.

[6] Del Re E. and Ruggieri M. Satellite Communications and

Navigation Systems,Springer, New York, 2008. 765 p.

[7] Seedhouse E. Military Satellites, Current Status and

Future Prospects, SpaceRef, 2012.

[8] Nejat A., Digital Satellite Communications Systems and

Technologies – Military and Civil Applications,

Kluwer Academic Publishers (Springer), Dordrecht,

Holland, 1992. 597 p.

[9] Diggelen V. F., A-GPS, Assisted GPS, GNSS and SBAS,

Artech House, Boston, 2009.

[10] Orbcomm Web Sites: Available from:

<www.orbcomm.com>.

[11] Kaplan D. E., Understanding GPS Principles and

Applications, Artech House, London, 1996.

[12] Grewal M.S., at al, Global Positioning Systems, Inertial

Navigation, and Integration, Wiley, London, 2008.

[13] Cobham Web Sites: Available from:

<www.cobham.com>.

[14] Iridium Web Sites: Available from:

<www.iridium.com>.

[15] Quake Web Sites: <www.quakeglobal.com>.

[16] Globalstar Web Sites: Available from:

<www.globalstar.com>.

[17] CNS Systems, Maritime Radio and Satellite

Communication Systems, Durban, South Africa, 2019.

[18] Ilcev D. S., Global Ship Tracking and Automatic

Identification System, CNS Systems, Durban, South

Africa, 2011,

[19] Orbcomm, Global Visibility Beyond Coastal Regions,

AIS - Orbcomm Satellite System, Rochelle Park, 2015,

[20] Weintrit, A., & Neumann, T. Information,

communication and environment: Marine navigation

and safety of sea transportation. (pp. 1-284)

doi:10.1201/b18514, 2015