See , you have made a fool out of yourself
GPS gives CURRENT position in latitude/longitude and not past positions ... Lat/long is not the same as the national grid reference which for every country can be different , lat/long is a global standard , the national grid reference is defined by the ordnance survey of the respective country , to convert from lat/long to national grid , formula is used ... do you understand the implications of this ?
Also , GPS does not give a trail of past positions
Trail of past positions only there in devices that have logging capability , which most commonly available gps receivers dont have and certainly those heading out for such like acts will not carry devices with loggers
This is just another one of those 'milk pack' found on militant , 'id card' found on militant