I am working on a final year project whereby I have decided to map the indian railway on my computer screen and show the whereabout of any particular train at a precise location.
My questions are
Is it possible to upload data from a moving vehical to a GPS satellite and then receive it at my selected console
What are the usable frequensies as specified by the requirements
Is there any site where i can get the complete information
Please help.
Ive got 6 months in hand
Thank you

 

The 'domes' that I see on top of tractor-trailers verifies what I think I know - that they've been doing this for years in the trucking industry - at least here in the US. The dome is a GPS antenna and if I am not mistaken the system reports via satellite, cell phone or local VHF/UHF link.

Amateur radio operators have their own APRS - Automated Position Reporting System. Take a look in current ham radio publications for info. A recent copy of QST published by ARRL details a relatively simple project where a simple hand-held GPS unit is interfaced with a hand-held ham transceiver. I presume that a similar unit (or many more) exists to recieve and process the data.

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stevez

 

i dont believe u can upload anything to a GPS satalite ,they are made only for recieving..

 

Correct. The GPS satellite is only a transmitter and does not itself have any information on where the receivers are.

A GPS receiver is far too difficult to build, but there's a standard NEMA format that they all have as a serial data output. You can buy off-the-shelf GPS receivers cheap with varying degrees of accuracy and signal acquisition capabilities. The output's easy to read with a microcontroller.

The radio link is the hard part. You can only build short range line-of-sight transmitters in most places due to the local airwave laws. You could do a network of powered repeaters to relay the information along. Or connect with an external data service like a cellphone system, but you'll need to have a contract with another provider to do it.