US 11,719,716 B1
Measuring distance traversed or speed
Alexandre Toutov, Inverary (CA); and Pavlo Borsuk, Kyiv (UA)
Assigned to Astra Navigation, Inc., Escondido, CA (US)
Filed by Astra Navigation, Inc., Escondido, CA (US)
Filed on May 12, 2022, as Appl. No. 17/743,336.
Int. Cl. G01P 3/42 (2006.01); G01B 7/02 (2006.01); G01R 33/07 (2006.01); B64C 39/02 (2023.01); G01R 33/09 (2006.01)
CPC G01P 3/42 (2013.01) [G01B 7/023 (2013.01); B64C 39/024 (2013.01); G01R 33/072 (2013.01); G01R 33/091 (2013.01); G01R 33/093 (2013.01)] 30 Claims
OG exemplary drawing
 
1. An apparatus comprising:
a first magnetometer operable to measure a magnetic field, wherein the first magnetometer comprises a first coordinate frame that comprises a first x axis, a first y axis, and a first z axis;
a second magnetometer operable to measure the magnetic field, wherein:
the second magnetometer comprises a second coordinate frame that comprises a second x axis, a second y axis, and a second z axis;
each of one or more of the second x axis, the second y axis, or the second z axis has a predetermined orientation relative to the first x axis, the first y axis, or the first z axis; and
the first and second magnetometers are a predetermined distance apart from each other in a direction;
one or more computer-readable non-transitory storage media embodying logic that is operable when executed to:
access a first measurement of the magnetic field by the first magnetometer at a first time;
access a second measurement of the magnetic field by the second magnetometer at a second time;
compare the first measurement with the second measurement;
based at least in part on the comparison, determine that the first measurement approximately coincides with the second measurement; and
based at least in part on the coincidence, determine that a device comprising the first and second magnetometers has traversed the predetermined distance in the direction that they are apart from each other.