I am new with QGIS.
I want to study the performance of different GPS receivers, and to do so I need to compute the error made by each one. The problem is that I don't have any reference to be compared with the coordinates provided by the receivers (which are installed on a car in movement), so I want to generate it myself using a GIS software.
The idea is to stick my GPS waypoints to the closest road (just as Google Maps app) to create a new route that would remain always within the road. And then I would like to (somehow) import this new data to matlab (for example, in CSV format) in order to compute the positioning error.
Is it possible or I should try something else?
I have seen that there are many functions available using PostGIS, and I have tried with ST_ClosestPoint (http://postgis.net/docs/ST_ClosestPoint.html) without any luck.
What is the correct way of using this function if I want to use the polylines of my city and the position fixes of my receiver as inputs ?