GPS use in space is limited by a number of factors, of both technical and administrative in nature. The limits to commercial GPS in terms of altitude and speed, means that a low cost commercial GPS is not an option for a satellite.
One option is to get the necessary permits to have a "unlocked GPS", but in addition to this, there is a number of technical challenges, linked mostly to the speed with which the satellite is travelling, and to the tumbling it is undergoing.
Euroluna is looking for a student or electronics interested person, to combine a low cost GPS receiver with a space approved OBC. The task would be to find a GPS chip, possibly of older design, acquire knowledge to modify the receiver so that it provides single "packages" received from GPS satellites to a micro processor, for instance one of Gomspaces ARM processors. Info might be GPS satellite position, time of measurement and distance to that GPS satellite. The aim should also be to build the hardware, and then to interface these single GPS measurements in "raw" format and make the necessary ARM software to calculate the orbit and position. This will be based on a mathematical model (prediction) for the orbit (circular or just slightly elliptic), initially very imprecise.
High doppler shift should simply be ignored, thus concentrate on those GPS satellites that has low doppler shift values, we might still be able to get some useful signals.
In practice this means to turn the positioning system "on its head": use the satellites that are furthest away as the basis for the positioning!!
