The court summons photo had the GPS co-ordinates of the vans location embedded in the corner. So I types them in to Google Maps and it supposedly showed that the van was 50 meters away from the road in a farmers field. I tried again with other mapping sources including Ordnance Survey Ireland - all produced the same result.
So our case was simple, if the GPS in the van was so inaccurate then that called in to question the accuracy of the rest of the attached equipment - including the speed detection gear.
So I built up a portfolio of documents from both government, commercial and academic sources stating that the GPS equipment in the van should have been more accurate - to at least 5m and ideally more than that. I was also able to call upon my experience having worked on various GIS systems and on the development of lone worker emergency beacons in the past.
When I spoke for my wife in court the prosecutor asked me if I was was a certified GPS engineer. I said that I didn't believe such a title existed and that I was offering evidence based on my professional experience. But that was enough to sway the judge who said that unless I had someone from "GPS" [sic] with me than my evidence counted for nothing.
Fair play to the guy in the article for putting up a fight.