Patent attributes
A feature quantity calculation unit calculates one or more predetermined types of feature quantities using information correlated to respective extracted peaks. An environment determination unit calculates a specific environment probability from a calculation result of the feature quantity calculation unit using the positive distribution and a non-specific environment probability from a calculation result of the feature quantity calculation unit using the negative distribution. The environment determination unit further determines whether the mobile body is in the specific environment or the non-specific environment in accordance with a result of integration of the specific environment probability and the non-specific environment probability which are calculated for respective feature quantities.
