A compass system includes a processing circuit configured to use the deviations for each of the plurality of headings to calculate a plurality of compass deviation coefficients representative of different types of noise sources. At least one compass deviation coefficient is determined based on a database of geographic zone error factors stored in the memory device and based on a position of the compass. The processing circuit is configured to update the database of geographic zone error factors using an internet connection. The processing circuit is configured to store the deviation coefficients in memory and to at least one of calibrate the compass and adjust an output from the compass using the compass deviation coefficients.