GLonass GPS Antenna

Internal Patch:

• Frequency: 1575MHZ/1602MHz
• Center Frequency: 1593MHz
• V.S.W.R: 1.5:1
• Band Width: 55 MHz Min. at -10dB
• Impendence: 50 ohm
• Peak Gain: 5dBic Min/1575MHz. 4dBic Min/1602~1616MHz.
• Gain Coverage:≥- 4dBic at -90°~90°(over75% volume)
• Power Handling : 1 watt
• Polarization : RHCP

GPS – GLONASS -Galileo

Global Positioning System (GPS)
The Global Positioning System (GPS) is a global navigation satellite system (GNSS) developed by the United States Department of Defense and managed by the United States Air Force 50th Space Wing. It is the only fully functional GNSS in the world, can be used freely by anyone, anywhere, and is often used by civilians for navigation purposes. It uses a constellation of between 24 and 32 medium Earth orbit satellites that transmit precise radiowave signals, which allow GPS receivers to determine their current location, the time, and their velocity. Its official name is NAVSTAR GPS.

Since it became fully operational on April 27, 1995, GPS has become a widely used aid to navigation worldwide, and a useful tool for map-making, land surveying, commerce, scientific uses, tracking and surveillance, and hobbies such as geocaching.

Each GPS satellite continuously broadcasts a Navigation Message at 50 bit/s giving the time-of-week, GPS week number and satellite health information (all transmitted in the first part of the message), an ephemeris (transmitted in the second part of the message) and an almanac (later part of the message). The messages are sent in frames, each taking 30 seconds to transmit 1500 bits.

Satellite frequencies

• L1 (1575.42 MHz): Mix of Navigation Message, coarse-acquisition (C/A) code and encrypted precision P(Y) code, plus the new L1C on future Block III satellites.
• L2 (1227.60 MHz): P(Y) code, plus the new L2C code on the Block IIR-M and newer satellites.
• L3 (1381.05 MHz): Used by the Nuclear Detonation (NUDET) Detection System Payload (NDS) to signal detection of nuclear detonations and other high-energy infrared events. Used to enforce nuclear test ban treaties.
• L4 (1379.913 MHz): Being studied for additional ionospheric correction.
• L5 (1176.45 MHz): Proposed for use as a civilian safety-of-life (SoL) signal (see GPS modernization). This frequency falls into an internationally protected range for aeronautical navigation, promising little or no interference under all circumstances. The first Block IIF satellite that would provide this signal is set to be launched in 2009.

_{Source Wikipedia: http://en.wikipedia.org/wiki/Global_Positioning_System}

GLONASS

GLONASS (Russian: ГЛОНАСС, abbreviation of ГЛОбальная НАвигационная Спутниковая Система; tr.: GLObal'naya NAvigatsionnaya Sputnikovaya Sistema; "GLObal NAvigation Satellite System" in English) is a radio-based satellite navigation system, developed by the former Soviet Union and now operated for the Russian government by the Russian Space Forces. It is an alternative and complementary to the United States' Global Positioning System (GPS), the Chinese Compass navigation system, and the planned Galileo positioning system of the European Union (EU).

Development on the GLONASS began in 1976, with a goal of global coverage by 1991. Beginning on 12 October 1982, numerous rocket launches added satellites to the system until the constellation was completed in 1995. Following completion, the system rapidly fell into disrepair with the collapse of the Russian economy. Beginning in 2001, Russia committed to restoring the system, and in recent years has diversified, introducing the Indian government as a partner, and accelerated the program with a goal of restoring global coverage by 2009.

GLONASS satellites transmit two types of signal: a standard precision (SP) signal and an obfuscated high precision (HP) signal.

All satellites transmit the same code as their SP signal, however each transmits on a different frequency using a 15-channel frequency division multiple access (FDMA) technique spanning either side from 1602.0 MHz, known as the L1 band. The center frequency is 1602 MHz + n × 0.5625 MHz, where n is a satellite's frequency channel number (n=−7,−6,−5,...,7).

The HP signal is broadcast in phase quadrature with the SP signal, effectively sharing the same carrier wave as the SP signal, but with a ten times higher bandwidth than the SP signal.

The L2 signals use the same FDMA as the L1 band signals, but transmit straddling 1246 MHz with the center frequency determined by the equation 1246 MHz + n×0.4375 MHz, where n spans the same range as for L1.

<sub>As of February 2009, the GLONASS system consists of 20 satellites, of which 19 are operational, and one is undergoing maintenance. The system requires 18 satellites for continuous navigation services covering the entire territory of the Russian Federation, and 24 satellites to provide services worldwide. The GLONASS system now covers 100% of Russian territory.

Source Wikipedia: http://en.wikipedia.org/wiki/Glonass</sub>

Galileo (satellite navigation)

Galileo is a global navigation satellite system (GNSS) currently being built by the European Union (EU) and European Space Agency (ESA). The €3.4 billion project is an alternative and complementary to the U.S. Global Positioning System (GPS) and the Russian GLONASS. On 30 November 2007 the 27 EU transportation ministers involved reached an agreement that it should be operational by 2013.

Galileo is intended to provide more precise measurements than available through GPS or GLONASS (Galileo will be accurate down to the metre range) including the height (altitude) above sea level, and better positioning services at high latitudes. The political aim is to provide an independent positioning system upon which European nations can rely even in times of war or political disagreement, since Russia or the USA could disable use of their national systems by others (through encryption).

Like the US GPS, use of basic (open) Galileo services will be free for everyone. However, more qualified services will be accessible with pecuniary or military restrictions.

There will be four different navigation services available:

GALILEO wil provide four basic satellite-only services. These services will be provided worldwide and independently from other systems by combining Galileo signals-in-space:

GALILEO Open Service (OS) - This service results from a combination of open signals, free of user charge, and provides superior position and timing performance compared to other GNSS systems. The OS signals will be broadcast in two bands, at 1164–1214 MHz and at 1563–1591 MHz. It is expected that most future mass market receivers, such as automotive navigation systems, will process both the GPS C/A and the Galileo OS signals, for maximum coverage.

GALILEO Commercial Service (CS) - Provides access to two additional signals, to allow for a higher data throughput rate and to enable users to improve accuracy. The signals are encrypted. A service guarantee is envisaged for this service. The encrypted Commercial Service (CS) will be available for a fee and will offer an accuracy of better than 1 m. The CS can also be complemented by ground stations to bring the accuracy down to less than 10 cm. This signal will be broadcast in three frequency bands, the two used for the OS signals, as well as at 1260–1300 MHz.

ALILEO Public Regulated Service (PRS) - provides position and timing to specific users requiring a high continuity of service, with controlled access. Two PRS navigation signals with encrypted ranging codes and data will be available. The encrypted Public Regulated Service (PRS) and Safety of Life Service (SoL) will both provide an accuracy comparable to the Open Service. Their main aim is robustness against jamming and the reliable detection of problems within 10 seconds. They will be targeted at security authorities (police, military, etc.) and safety-critical transport applications (air-traffic control, automated aircraft landing, etc.), respectively.

GALILEO Safety of Life (SoL) service - Will be offered and guaranteed to the critical transport community, e.g. aviation, maritime, etc., delivering enhanced performance that includes the provision of the integrity function, i.e. a warning of system malfunction that will reach the user in a given alarm time. This service will be certified against applicable standards and performance, for example the SBAS standards of the International Civil Aviation Organisation (ICAO) in 2009.

In addition, the Galileo satellites will be able to detect and report signals from Cospas-Sarsat search-and-rescue beacons in the 406.0–406.1 MHz band, which makes them a part of the Global Maritime Distress Safety System.

_{Source Wikipedia: http://en.wikipedia.org/wiki/Galileo_(satellite_navigation)}