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The Committee included this recommendation in the Plan of Action proposed in its
report to the General Assembly on the review of the implementation of the
recommendations of UNISPACE III. In 2004, in its resolution 59/2, the General
Assembly endorsed the Plan of Action. In the same resolution, the General
Assembly invited GNSS and augmentation system providers to consider
establishing an ICG in order to maximize the benefits of the use and applications
of GNSS to support sustainable development [36] .
-
-
-
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A satellite navigation or SAT NAV system is a system of satellites that
provide autonomous geo-spatial positioning with global coverage. It allows small
electronic receivers to determine their location (longitude, latitude, and altitude) to
within a few meters using time signals transmitted along a line-of-sight by radio
from satellites. Receivers calculate the precise time as well as position, which can
be used as a reference for scientific experiments. A satellite navigation system with
global coverage may be termed a global navigation satellite system or GNSS [36].
satellite navigation)
.
As of October 2011, only the United States NAVSTAR Global
Positioning System (GPS) and the Russian GLONASS are fully globally
operational GNSSs. China is in the process of expanding its regional Beidou
navigation system into the global Compass navigation system by 2020. The
European Union's Galileo positioning system is a GNSS in initial deployment
phase, scheduled to be fully operational by 2020 at the earliest. Several countries
including France, Japan and India are in the process of developing regional
navigation systems [36] .
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Satellite navigation systems that provide enhanced accuracy and integrity
monitoring usable for civil navigation are classified as follows:
GNSS-1 is the first generation system and is the combination of
existing satellite navigation systems (GPS and GLONASS), with Satellite Based
Augmentation Systems (SBAS) or Ground Based Augmentation Systems (GBAS).
In the United States, the satellite based component is the Wide Area Augmentation
System (WAAS), in Europe it is the European Geostationary Navigation Overlay
Service (EGNOS), and in Japan it is the Multi-Functional Satellite Augmentation
System (MSAS). Ground based augmentation is provided by systems like the
Local Area Augmentation System (LAAS).
GNSS-2 is the second generation of systems that independently
provides a full civilian satellite navigation system, exemplified by the European
Galileo positioning system. These systems will provide the accuracy and integrity
monitoring necessary for civil navigation. This system consists of L1 and L2
frequencies for civil use and L5 for system integrity. Development is also in
progress to provide GPS with civil use L2 and L5 frequencies, making it a GNSS-2
system.
Core Satellite navigation systems, currently GPS (U.S.), GLONASS
(Russia), Compass (China), and Galileo (EU).
Global Satellite Based Augmentation Systems (SBAS) such as
Omnistar and StarFire.
Regional SBAS including WAAS (U.S.), EGNOS (EU), MSAS
(Japan) and GAGAN (India).
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Regional Satellite Navigation Systems such as China's Beidou, India's
yet-to-be-operational IRNSS, and Japan's proposed QZSS.
Continental scale Ground Based Augmentation Systems (GBAS) for
example the Australian GRAS and the US Department of Transportation National
Differential GPS (DGPS) service [36] .
-
(LAAS).
-2
Galileo
-2.
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the ground based DECCA, LORAN, GEE andOmega radio navigation systems,
which used terrestrial longwave radio transmitters instead of satellites. As such
positioning systems broadcast a radio pulse from a known "master" location,
followed by repeated pulses from a number of "slave" stations. The occurrence of
delay between the reception and sending of the signal at the slaves was carefully
controlled, allowing the receivers to compare the delay between reception and the
delay between sending. Mathematically, the distance to each of the slaves could be
determined, providing a fix from this evaluation [36] .
57
It was also accurately predicted by mathematical calculations that a part of
an orbiting satellite's broadcast included its precise orbital data. With the sole
purpose of ensuring accuracy, the US Naval Observatory (USNO) continuously
observed the precise orbits of these satellites. Once a satellite's orbit deviated, the
USNO would send the updated information to the satellite. Subsequent broadcasts
from an updated satellite would contain the most recent accurate information about
its orbit [36] .
-
«Navigation
Automobiles can be equipped with GNSS receivers at the factory or as
aftermarket equipment. Units often display moving maps and information about
location, speed, direction, and nearby streets and points of interest.
Aircraft navigation systems usually display a "moving map" and are
often connected to the autopilot for enroute navigation. Cockpit-mounted GNSS
58
receivers and glass cockpits are appearing in general aviation aircraft of all sizes,
using technologies such as WAAS or LAAS to increase accuracy. Many of these
systems may be certified for instrument flight rules navigation, and some can also
be used for final approach and landing operations. Glider pilots use GNSS Flight
Recorders to log GNSS data verifying their arrival at turn points in gliding
competitions. Flight computers installed in many gliders also use GNSS to
compute wind speed aloft, and glide paths to waypoints such as alternate airports
or mountain passes, to aid en route decision making for cross-country soaring.
Boats and ships can use GNSS to navigate all of the world's lakes,
seas and oceans. Maritime GNSS units include functions useful on water, such as
"man overboard" (MOB) functions that allow instantly marking the location where
a person has fallen overboard, which simplifies rescue efforts. GNSS may be
connected to the ships self-steering gear and hartplotters using the NMEA 0183
interface. GNSS can also improve the security of shipping traffic by enabling AIS
[36] .
Навигация
WAAS LAAS
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(AIS).
Spacecraft are now beginning to use GNSS as a navigational tool. The
addition of a GNSS receiver to a spacecraft allows precise orbit determination
without ground tracking. This, in turn, enables autonomous spacecraft navigation,
formation flying, and autonomous rendezvous. The use of GNSS in MEO, GEO,
HEO, and highly elliptical orbits is feasible only if the receiver can acquire and
track the much weaker (15 - 20 dB) GNSS side-lobe signals. This design
constraint, and the radiation environment found in space, prevents the use of COTS
receivers. Low earth orbit satellite constellations such as the one operated by
Orbcomm uses GPS receivers on all satellites [36] .
(
60
)
«Other uses
Precise time reference many systems that must be accurately
synchronized use GNSS as a source of accurate time. GNSS can be used as a
reference clock for time code generators or Network Time Protocol (NTP) time
servers. Sensors (for seismology or other monitoring application), can use GNSS
as a precise time source, so events may be timed accurately. Time division multiple
access (TDMA) communications networks often rely on this precise timing to
synchronize RF generating equipment, network equipment, and multiplexers [36].
Другие области применения.
Точная временная привязка
RF)-
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«Weather Prediction Improvements. Measurement of atmospheric
bending of GNSS satellite signals by specialized GNSS receivers in orbital
satellites can be used to determine atmospheric conditions such as air density,
temperature, moisture and electron density. Such information from a set of six
micro-satellites, launched in April 2006, called the Constellation of Observing
System for Meteorology, Ionosphere and Climate COSMIC has been proven to
improve the accuracy of weather prediction models [36] .
Улучшение прогнозов погоды.
(
)
(Рисунок 1.)