sir ,
i am Geetha, b tech final year student of electronics and communication .
I am in search of seminar topics.i noticed the topic GNSS AUGMENTATION SYSTEM.i want more details of this topic including system working, principle of working, applications, advantages, disadvantages,todays role of this in human living.SIMPLY A SEMINAR REPORT.
hopefully .
geetha

GNSS augmentation system
Augmentation of a global navigation satellite system means improving the navigation system's functionalities like accuracy, reliability, and availability, through the integration of external information into the calculation process. based on how the GNSS sensor receives the external information, several variants of the system exist.

A satellite-based augmentation system
It supports wide-area or regional augmentation by the use of additional satellite-broadcast messages. They may contain multiple ground stations strategically positioned through surveying. One or more GNSS satellites' measurements is taken by the ground stations. information messages are created and sent to one or more satellites based on these measurements.

Ground-based augmentation system
terrestrial radio messages are used by these systems , ground-based augmentation system (GBAS) and ground-based regional augmentation system (GRAS). They also generally contain many accurately surveyed ground stations. They transmit signals in the very high frequency (VHF) or ultra high frequency (UHF) bands .

further details can be obtained from:
http://en.wikipediawiki/GNSS_augmentation
http://answerstopic/gnss-augmentation
http://positimnavsys_overview.html
http://aprsafdata/aprsaf15_data/csawg/CSAWG_6c.pdf