Securing a geographic position

A device for securing a geographic position of a vehicle, the device comprising:

• multiple information sources, wherein each of the information source is configured to provide items of information which indicate the position of the vehicle, wherein:
• each of the information sources is assigned a matcher and a validator;
• the matcher is configured to determine an individual position based on the items of information of the information source and items of surroundings information, including map data, in the region of a position hypothesis;
• and
• the validator is configured to validate the provided items of information if the individual position deviates by not more than a predetermined amount from the position hypothesis;
• a processing unit for determining the position of the vehicle based on the validated items of information, wherein the processing unit is configured to:
• determine a change of a quality of the items of surroundings information;
• and
• based on the change, determine a probability at which the determined position deviates by more than the predetermined amount from an actual position;
• wherein the probability is determined by way of a Markov chain, which models the change of the quality of the items of surroundings information;
• and
• wherein a probability of a rapid deterioration of the quality is determined based on observations of past validator KPIs.