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GLONASS

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GLONASS, which stands for the Global Navigation Satellite System, is a Russian radionavigation-satellite service.

Stamp-russia2016-glonass
Stamp-russia2016-glonass

It functions as a vital alternative to the American Global Positioning System (GPS). By providing real-time position and velocity determination, it serves both military and civilian users globally. When a device supports both GPS and GLONASS, it can access more satellites simultaneously. This increased availability allows for faster and more accurate position fixes. This is particularly useful in built-up urban areas where tall buildings might obscure the view of certain satellites.

GPSTest screenshot (2025)
GPSTest screenshot (2025)

The system operates through a specific orbital arrangement designed for global reach. The satellites are positioned in a middle circular orbit at a specific altitude. They possess an orbital period of 11 hours and 16 minutes. This means a single satellite completes 17 revolutions every 8 sidereal days to pass over the same location. The constellation is organized into three orbital planes, with eight evenly spaced satellites in each plane. A full constellation requires 24 satellites to provide global coverage. However, only 18 satellites are necessary to cover the territory of Russia. To calculate an exact position, a receiver must be within range of at least four satellites.

One of the most important features of GLONASS is its high orbital inclination. The satellites orbit at an inclination of 64.8 degrees. This high tilt makes the system especially suited for use in high latitudes, such as the North or South Poles. In these polar regions, receiving a standard GPS signal can often be problematic. Because of this orbital design, GLONASS provides excellent supplemental positioning for northern areas. The system's hardware also continues to evolve, with the latest GLONASS-K2 version launching in 2023.

Glonass-K - MAKS2015part8-12
Glonass-K - MAKS2015part8-12

The technical method for transmitting signals is known as frequency-division multiple access, or FDMA. In this technique, each satellite transmits on a different frequency channel. The signals are transmitted in a 38-degree cone using right-hand circular polarization. The satellites broadcast two primary types of signals: open standard-precision signals and obfuscated high-precision signals. The standard-precision signals, such as L1OF and L2OF, are available to the public. The high-precision signals, like L1SF and L2SF, are intended for authorized users like the military. These signals use similar DSSS encoding and binary phase-shift keying (BPSK) modulation as GPS signals.

Detailed signal management is required to maintain accuracy and security. The L1 band signals center around 1602.0 MHz, with frequencies varying based on a specific channel number. The L2 band signals straddle 1246 MHz. To manage the 24-satellite constellation using only 15 channels, the system uses identical frequency channels for antipodal satellite pairs. These are satellites on opposite sides of the planet that are never visible to a user at the same time. The high-precision signal is broadcast in phase quadrature with the standard signal. This allows it to share the same carrier wave while maintaining a ten-times-higher bandwidth. Unlike the American P(Y) code which uses an encrypting W code, GLONASS restricted codes use security through obscurity.

The history of GLONASS began with development in the Soviet Union in 1976. Numerous rocket launches began on 12 October 1982 to build the constellation. While the system was completed in 1995, it faced a decline in capacity during the late 1990s. In 2001, the Russian government made restoring the system a priority, which significantly increased funding. GLONASS became the most expensive program of Roscosmos, consuming one-third of its budget in 2010. By October 2011, the full 24-satellite constellation was restored, enabling full global coverage.

GLONASS GroundSegment
GLONASS GroundSegment

Accuracy is maintained through precise coordinate systems and data updates. GLONASS uses a coordinate datum known as PZ-90, which is based on Earth parameters from 1990. This differs from the GPS WGS 84 datum, which uses the North Pole location from 1984. Since 2013, the PZ-90.11 version has been broadcast to align with international reference systems. At peak efficiency, the standard signal provides horizontal accuracy within 5 to 10 meters. It also provides vertical positioning and precise velocity vectors. This data is supported by continuous updates from the Ground Control segment.

GLONASS module 1K-181
GLONASS module 1K-181

Today, GLONASS technology is integrated into many different types of hardware.

Glonass-receiver
Glonass-receiver

It can be found in ruggedized receivers used by the military.

GLONASS GPS Personal Radio Beacon
GLONASS GPS Personal Radio Beacon

It is also used in handheld personal radio beacons for safety. Even modern research is looking toward the future, such as the development of CDMA signals. These new signals aim to improve interoperability with other systems like Galileo. As the system modernizes, it continues to connect satellite technology to global navigation needs.

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🖼️ Images & Media (7)
File:Glonass-receiver.jpg
Glonass-receiver.jpg
File:GLONASS GPS Personal Radio Beacon.jpg
GLONASS GPS Personal Radio Beacon.jpg
File:Glonass-K - MAKS2015part8-12.jpg
Glonass-K - MAKS2015part8-12.jpg
File:GLONASS GroundSegment.jpg
GLONASS GroundSegment.jpg
File:Stamp-russia2016-glonass.png
Stamp-russia2016-glonass.png
File:GLONASS module 1K-181.jpg
GLONASS module 1K-181.jpg
GPSTest screenshot (2025).webp
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