explanation how GLONASS work

1. GLONASS
GLOBALNAYA NAVIGAZIONNAYA
SPUTNIKOVAYA SISTEMA
BY NIKHIL SAPRE
A501158821020

2. GNSS
GPS
GLONASS
QZSS
BeiDou
GALILEO
GAGAN

3. GPS AND
GNSS
• Many people get GNSS and GPS technology confused. A
good way to think about the Global Navigation Satellite
Systems (GNSS) is as the backbone (or underlying
technology) behind GPS. The Global Positioning System
(GPS) GPS is a GNSS constellation, but GNSS is not
always GPS. GPS is one of the 6 GNSS constellations
used around the world.
• The 6 GNSS constellations include GPS (US), QZSS
(Japan), BEIDOU (China), GALILEO (EU), GLONASS
(Russia), and GAGAN (India). We'll cover the GLONASS
constellation in-depth.

4. GLONASS IS RUSSIA'S VERSION OF
GPS. DEVELOPMENT BEGAN IN 1976
BY THE SOVIET UNION
The US GPS network includes 31 satellites, while
GLONASS uses 24 satellites. The 2 systems also differ
somewhat in terms of accuracy. GLONASS position
accuracy is 5-10m while GPS is 3.5-7.8m.
GLONASS operates at 1.602 GHz and GPS at 1.57542 GHz
(L1 signal)
GLONASS is a great backup for GPS. When GPS signals are
lost (like when you're between tall buildings) GLONASS
has your back.
This Photo by Unknown Author is licensed under CC BY-SA

6. GLONASS IS A SPACE-BASED GLOBAL NAVIGATION SATELLITE SYSTEM
(GNSS) THAT PROVIDES RELIABLE POSITIONING, NAVIGATION, AND
TIMING SERVICES TO USERS ON A CONTINUOUS WORLDWIDE BASIS
FREELY AVAILABLE TO ALL.
• The basic observable in a GNSS
system is the time required for a
signal to travel from the satellite
(transmitter) to the receiver. This
travelling time, multiplied by the
speed of light, provides a measure
of the apparent distance (pseudo
range) between them.
The use of GLONASS in addition to GPS provides
very significant advantages:
• Increased satellite signal observations
• markedly increased spatial distribution of
visible satellites
• reduced Horizontal and Vertical Dilution of
Precision (DOP) factors
• decreased occupation times mean faster RTK
results

7. IN ORDER TO DETERMINE A POSITION IN GPS-ONLY MODE THE RECEIVER MUST
TRACK A MINIMUM OF FOUR SATELLITES, REPRESENTING THE FOUR
UNKNOWNS OF 3-D POSITION AND TIME. IN COMBINED GPS/GLONASS MODE,
THE RECEIVER MUST TRACK FIVE SATELLITES, REPRESENTING THE SAME FOUR
PREVIOUS UNKNOWNS AND AT LEAST ONE GLONASS SATELLITE TO DETERMINE
THE GPS/GLONASS TIME OFFSET.

8. GLONASS IS COMPRISED OF THREE SEGMENTS:
A GLONASS SPACE SEGMENT (SS),
A GLONASS GROUND SEGMENT (CS), AND
A GLONASS USER SEGMENT (US)
• Space Segment is composed of 24 satellites in three orbital planes
whose ascending nodes are 120 deg apart. Eight satellites are equally
spaced in each plane with the argument of latitude displacement of 45
deg. The satellites operate in circular orbits at an altitude of 19100-
km, an inclination of 64.8 deg and each satellite completes the orbit in
approximately 11 hours 15 minutes.

9. • Ground Segment includes the
System Control Center and the
network of the Command and
Tracking Stations that are located
throughout the territory of Russia.
The control segment provides
monitoring
of GLONASS constellation status,
correction to the orbital parameters
and navigation data uploading.
• User Segment consists of the
user receivers which compute
coordinates, velocity and time
from the GLONASS navigation
signals.

10. THANK YOU
Nikhil Sapre