Dynamic selection of parameters for navigation

One or more computer-readable non-transitory storage media embodying software that is operable when executed to:

• access a magnetic-field map of a region comprising data that represents magnetic-field values that correspond to locations in the region;
• access a sample magnetic recording comprising data that represents a time or distance series of magnetic measurements made along a path in the region;
• at least approximately align the sample magnetic recording to the magnetic-field map;
• based on the alignment:
• generate a first set of parameters for aligning subsequent magnetic recordings to the magnetic-field map across a substantial entirety of the magnetic-field map;
• and
• generate one or more second sets of parameters for aligning subsequent magnetic recordings to the magnetic-field map in one or more subdivisions of the magnetic-field map, wherein each of the second sets of parameters corresponds to one of the subdivisions;
• associate the first and second sets of parameters with the magnetic-field map;
• and
• provide the magnetic-field map with the first and second sets of parameters associated with it for subsequent navigation.

A system comprising:

• one or more processors;
• and
• one or more computer-readable non-transitory storage media coupled to one or more of the processors and comprising instructions operable when executed by one or more of the processors to cause the system to:
• access a magnetic-field map of a region comprising data that represents magnetic-field values that correspond to locations in the region;
• access a sample magnetic recording comprising data that represents a time or distance series of magnetic measurements made along a path in the region;
• at least approximately align the sample magnetic recording to the magnetic-field map;
• based on the alignment:
• generate a first set of parameters for aligning subsequent magnetic recordings to the magnetic-field map across a substantial entirety of the magnetic-field map;
• and
• generate one or more second sets of parameters for aligning subsequent magnetic recordings to the magnetic-field map in one or more subdivisions of the magnetic-field map, wherein each of the second sets of parameters corresponds to one of the subdivisions;
• associate the first and second sets of parameters with the magnetic-field map;
• and
• provide the magnetic-field map with the first and second sets of parameters associated with it for subsequent navigation.

A system comprising:

• means for accessing a magnetic-field map of a region comprising data that represents magnetic-field values that correspond to locations in the region;
• means for accessing a sample magnetic recording comprising data that represents a time or distance series of magnetic measurements made along a path in the region;
• means for at least approximately aligning the sample magnetic recording to the magnetic-field map;
• means for, based on the alignment:
• generating a first set of parameters for aligning subsequent magnetic recordings to the magnetic-field map across a substantial entirety of the magnetic-field map;
• and
• generating one or more second sets of parameters for aligning subsequent magnetic recordings to the magnetic-field map in one or more subdivisions of the magnetic-field map, wherein each of the second sets of parameters corresponds to one of the subdivisions;
• means for associating the first and second sets of parameters with the magnetic-field map;
• and
• means for providing the magnetic-field map with the first and second sets of parameters associated with it for subsequent navigation.