[FOSS-GPS] High accuracy positioning with low cost GPS devices: a FOSS project

Eugenio Realini eugenio.realini at gmail.com
Thu Oct 9 12:35:05 EDT 2008

I'm Eugenio Realini, Ph.D. student at Politecnico di Milano, Geomatics 
Laboratory [1] at Como campus (Italy).

I was simply amazed when I found out this list a few hours ago, since we 
just decided (few days ago) to continue the development of a GPS 
navigation software we have worked on for more than one year as FOSS.
The software was born as a research/teaching tool to study Kalman 
filtering algorithms on GPS observations and today it has become a 
real-time navigation software that tries to exploit at best low cost GPS 
chipsets in order to obtain highly accurate positioning (20 - 50 cm). 
This is done by applying double differences with respect to a (network 
of) permanent station(s) and linear/surface constraints. It works 
directly on the raw data (code and carrier phase) that can be obtained 
from some GPS chipsets (we are now using u-blox LEA-4T [2]) and relies 
on a GPRS/UMTS Internet connection to get data for the differential 

The software is still highly prototypal and it has been written in the 
framework of two Master's degree theses (a third one has just started). 
Up to now it has been developed in a MATLAB environment, but it is going 
to be converted in ANSI C during the next months.

We are thinking about designing it to run on Openmoko, but first we have 
to understand if there is any way of obtaining raw data from the u-blox 
GPS chipset it carries inside.


[1] http://geomatica.como.polimi.it/
[2] http://www.u-blox.com/products/lea_4t.html

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