2. Features
History
Reference Systems
Frame
Time System
Services
Segments
Signal Structure
Ranging Signals
3.
4. Union of Soviet Socialist Republics initiated GLONASS(Global naya
Navigatsion naya Sputnikovaya Sistema ) in mid 1970s
Developing starts from experience of Doppler Satellite system Tsikada.
7. Russian Federal Space Agency
Russian Ministry of Defense
Russian Agency of Control Systems
Russian Ministry of Transport
Russian Ministry of Industry ,Science and
Technology
Russian Mapping and Geodesy Agency
8. Coordinate system
PE-90(Parameters of Earth)
used for geodetic support of orbital missions and navigation
Parameter and value Description
a = 6 378 136 m Semi major axis of the ellipsoid
f = 1/298.257 839 303 Flattening of the ellipsoid
ωe = 7 292 115 · 10-11 rad s-1 Angular velocity of the earth
µ = 3 986 004.4 108 m3 s-2 Earth’s gravitational constant
0.35 ⋅ 10
Geocentric gravitational constant
of
atmosphere (GMA)
299,792,458 Speed of light (c)
9. • Origin: Earth’s center of mass being defined for the whole Earth
including
oceans and atmosphere.
• Axes:
Z-axis is directed to the Conventional Reference Pole that was defined
by
the International Earth Rotation and Reference Systems Service (IERS)
and
Bureau International de l'Heure (BIH);
X-axis is directed to the intersection point of the equatorial plane and the
Zero Meridian defined by BIH;
Y-axis completes a right-handed system.
• Scale: Conforms to the current state of knowledge of the speed of
light, the
geocentric gravitational constant as well as to the precision of the
satellite
laser ranging instruments.
• Orientation: Conforms to the Recommendations of BIH.
• Evolution: Zero rotation rate with respect to the ITRF2008
10.
11.
12. Standard Positioning Service:
Consists of C/A Code modulated on G1 carrier only
G1(1593-1610 MHz)
Accuracy
13 m ≤ horizontal error ≤ 100 m
22 m ≤ vertical error ≤ 156 m
Precise positioning service :
Consists of P Code modulated on G1 and G2 Carriers
16. Function
Tracking for orbit
Clock Determination
Upload of Navigation message to sates
Time Synchronization
Control offset between GLONASS and UTC
Procurement
Launch activities
17.
18. Interface Control Document (ICD)
Two Carrier
G1(1593-1610 MHz) and G2 (1239.6-1254 MHz) and
G3(1204.704MHZ)
C/A Code (Standard Accuracy Signal )and P Code(High Accuracy
Signal)
Implements Frequency Division Multiple Access(FDMA)
19. G1
Link 1, carrier frequency = 1 602.000
MHz
G2
Link 2, carrier frequency = 1 246.000
MHz
G3
Link 3, carrier frequency = 1 204.704
MHz (1)
C/A Standard-accuracy signal
P High-accuracy signal
Glonass signal lexicon
20. Carrier Frequencies
f1k = f1 + ∆ f1 k = 1 602.0000 + 0.5625 k [MHz] ,
f2k = f2 + ∆ f2 k = 1 246.0000 + 0.4375 k [MHz] ,
f3k = f3 + ∆ f3 k = 1 204.7040 + 0.4230 k [MHz] ,
Glonass Frequency Bands
Link Factor Frequency Increment Wavelength Frequency
G1 1 1 602.000 0.5625 18.7
ARNS/RNS
S
G2 7/9 1 246.000 0.4375 24.1 RNSS
G3 94/125 1 204.704 0.4230 24.9
ARNS/RNS
S
21. GLONASS relies on the FDMA principle and
therefore uses common PRN sequences for all
satellites.
the standard- and the high accuracy signal denoted
as C/A-code and P-code, respectively, are
modulated onto the carrier frequencies in phase
quadrature
Together with the ranging codes the navigation
message is BPSK-modulated onto the carrier
frequency.
25. Two different navigation messages are modulated onto the standard-
and the high-accuracy signal.
The navigation data of the standard-accuracy signal is structured into
super frames, frames, and strings.
A superframe has a duration of 2.5 minutes and is
subdivided into five frames of 30-second length each
A frame contains immediate
data of the transmitting satellite and non-immediate data from all other
satellites.
