Principle, Segment, Limitation, Error of GPS, DGPS, GLONASS, GALILEO

Principle, Segment, Limitation, Error of GPS, DGPS, GLONASS, GALILEO

GPS principle
Same as why three or four satellite using. See above answer.

GPS limitation
GPS doesn’t work on some places because of inclination of 55 degree to equator
No control by user
GPS jamming
GPS error

GPS segment
Ground base segment
Space segment
Receiver segment

GPS
27 satellite 24 operation 3 spare
6 orbit
20200 km above
55 degree inclined to equator
Period 11 h 58 m
5-10 m accuracy

DGPS
Where higher accuracy of position fixing required. (survey, drilling, oceanography.)
Used to enhance the accuracy of GPS system.
Not independent, GPS receiver needed
Coverage within 370 km of DGPS reference station
3-5 m accuracy

DGPS principle
DGPS reference station is situated at a fixed location.
From DGPS reference station GPS receiver tracks satellite and make calculation.
GPS receiver also make calculation for it’s actual position.
Finally, correction are sent to GPS user.

DGPS limitation
Not independent, GPS receiver needed.
Coverage within 370 km of DGPS reference station.
For greater coverage more DGPS reference station need to be added.
Lack of integrity
No control by user
GPS error

GLONASS
Russian based satellite system
GPS and Glonass share same principle

GLONASS
27 satellite 24 operation 3 spare
3 Orbit
19100 km above
64.8 degree inclination to equator
Period 11 h 16 m
5.6 m accuracy

GLONASS limitation
Lack of integrity
No control by user
Lack of availability
error

GLONASS error
Satellite clock error
User clock error
Ionospheric and tropospheric delay
Multipath error
Solar flare
Spoofing

GALILEO
European based satellite system
GPS, Glonass, Galileo share same principle

GALILEO
30 satellite 27 operation 3 spare
3 Orbit
23222 km above
56 degree inclination to equator
Period 14 h 05 m
4-15 m accuracy

GALILEO limitation
Lack of integrity
No control by user
Lack of availability
error

GALILEO used for
Search and rescue
Commercial Navigation

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KRP

Mr. KRP is the founder of sailorsknowit.com, he has a great experience about life at sea. You can get in touch with him by email at info@sailorsknowit.com