Systems and methods for determining an indoor or outdoor location of a mobile device

• US 10,602,476 B2
• Filed: 03/12/2019
• Issued: 03/24/2020
• Est. Priority Date: 08/01/2018
• Status: Active Grant

• Current Assignee: NextNav, LLC
• Original Assignee: NextNav, LLC
• Inventors: Dormody, Michael, Nagarajan, Badrinath, Raghupathy, Arun
• Primary Examiner(s): Cai, Wayne H
• Application Number:
  US16/351,271
• Publication Number:
  US 20200045668A1
• Time in Patent Office: 378 Days
• CPC Class Codes: G01S 2205/06 Emergency
• CPC Class Codes: G01S 5/012 Identifying whether indoors or outdoors
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: G01W 1/02 Instruments for indicating weather conditions by measuring two or more variables, e.g. humidity, pressure, temperature, cloud cover or wind speed G01W1/10 takes precedence
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 4/33 for indoor environments, e.g. buildings
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 64/003 locating network equipment

Abstract

Determining an indoor or outdoor location of a mobile device. Particular embodiments described herein determine a geographic area of potential locations in which a mobile device resides, identify any buildings that occupy part of the geographic area, and determine if the mobile device does not reside inside any building, the mobile device resides inside a particular building from the identified buildings, or that one or more of the identified buildings are candidate buildings in which the mobile device may reside based on the geographic area and building footprints of the identified buildings.

Claims

1. A method for determining an indoor or outdoor location of a mobile device, wherein the method comprises:

determining a user footprint;

identifying each building with a building footprint that at least partially overlaps with the user footprint; and

determining, based on the user footprint and the building footprints of the identified buildings, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides,

wherein determining, based on the user footprint and building footprints of the identified buildings, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides comprises;

determining an average building footprint of the building footprints of the identified buildings;

determining a first ratio representing an amount of the user footprint that is occupied by the building footprints of the identified buildings;

determining a second ratio representing a comparative size of the user footprint and the average building footprint; and

determining, based on the value of the first ratio and the value of the second ratio, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides.

2. The method of claim 1, wherein determining, based on the value of the first ratio and the value of the second ratio, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides comprises:

determining if the first ratio is zero;

if the first ratio is not zero, determining a first relationship specifying if the first ratio is less than or greater than a first threshold value, and determining a second relationship specifying if the second ratio is less than or greater than a second threshold value; and

determining, based on whether the first ratio is zero or based on the first and second relationships, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides.

3. The method of claim 2, wherein determining, based on whether the first ratio is zero or based on the first and second relationships, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides comprises:

determining that the mobile device does not reside inside any building when the first ratio is zero;

determining that the mobile device resides inside a building from the identified buildings with a building footprint that overlaps the user footprint more than any other building footprint of any other identified building when the first relationship specifies the first ratio is greater than the first threshold value, and the second relationship specifies the second ratio is not greater than the second threshold value; and

determining that the identified buildings are candidate buildings that include a building in which the mobile device resides (i) when the first relationship specifies the first ratio is greater than the first threshold value, and the second relationship specifies the second ratio is greater than the second threshold value, (ii) when the first relationship specifies the first ratio is not greater than the first threshold value, and the second relationship specifies the second ratio is not greater than the second threshold value, or (iii) when the first relationship specifies the first ratio is not greater than the first threshold value, and the second relationship specifies the second ratio is greater than the second threshold value.

4. The method of claim 2, wherein determining, based on whether the first ratio is zero or based on the first and second relationships, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides comprises:

determining that the mobile device does not reside inside any building when the first ratio is zero.

5. The method of claim 2, wherein determining, based on whether the first ratio is zero or based on the first and second relationships, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides comprises:

determining that the mobile device resides inside a building from the identified buildings with a building footprint that overlaps the user footprint more than any other building footprint of any other identified building when the first relationship specifies the first ratio is greater than the first threshold value, and the second relationship specifies the second ratio is not greater than the second threshold value.

6. The method of claim 2, wherein determining, based on whether the first ratio is zero or based on the first and second relationships, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides comprises:

determining that the identified buildings are candidate buildings that include a building in which the mobile device resides (i) when the first relationship specifies the first ratio is greater than the first threshold value, and the second relationship specifies the second ratio is greater than the second threshold value, (ii) when the first relationship specifies the first ratio is not greater than the first threshold value, and the second relationship specifies the second ratio is not greater than the second threshold value, or (iii) when the first relationship specifies the first ratio is not greater than the first threshold value, and the second relationship specifies the second ratio is greater than the second threshold value.

7. The method of claim 2, wherein determining, based on whether the first ratio is zero or based on the first and second relationships, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides comprises:

determining that the mobile device does not reside inside any building when the first ratio is zero;

determining that the mobile device resides inside a building from the identified buildings with a building footprint that overlaps the user footprint more than any other building footprint of any other identified building when the first relationship specifies the first ratio is greater than the first threshold value, and the second relationship specifies the second ratio is not greater than the second threshold value;

determining that the mobile device resides inside one of the identified buildings when the first relationship specifies the first ratio is greater than the first threshold value, and the second relationship specifies the second ratio is greater than the second threshold value; and

determining that the mobile device does not reside inside any building when (i) the first relationship specifies the first ratio is not greater than the first threshold value, and the second relationship specifies the second ratio is not greater than the second threshold value, or (ii) the first relationship specifies the first ratio is not greater than the first threshold value, and the second relationship specifies the second ratio is greater than the second threshold value.

8. The method of claim 2, wherein determining, based on whether the first ratio is zero or based on the first and second relationships, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides comprises:

determining that the mobile device resides inside one of the identified buildings when the first relationship specifies the first ratio is greater than the first threshold value, and the second relationship specifies the second ratio is greater than the second threshold value.

9. The method of claim 2, wherein determining, based on whether the first ratio is zero or based on the first and second relationships, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides comprises:

determining that the mobile device does not reside inside any building when (i) the first relationship specifies the first ratio is not greater than the first threshold value, and the second relationship specifies the second ratio is not greater than the second threshold value, or (ii) the first relationship specifies the first ratio is not greater than the first threshold value, and the second relationship specifies the second ratio is greater than the second threshold value.

10. A method for determining an indoor or outdoor location of a mobile device, wherein the method comprises:

determining a user footprint;

identifying each building with a building footprint that at least partially overlaps with the user footprint; and

determining, based on the user footprint and the building footprints of the identified buildings, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides;

if the mobile device is determined to not reside inside any building, calibrating a pressure sensor of the mobile device using one or more altitudes of outdoor ground terrain within the user footprint if the one or more altitudes are all within a threshold amount of altitude from each other; and

if the mobile device is determined to reside inside a particular building from the identified buildings or if one or more of the identified buildings are determined to be candidate buildings in which the mobile device resides, (i) determining a representative altitude of the mobile device and calibrating the pressure sensor of the mobile device using the determined representative altitude, or (ii) determining that the representative altitude of the mobile device cannot be determined for use in calibrating the pressure sensor,

wherein when the mobile device is determined to reside inside a particular building from the identified buildings or when one or more of the identified buildings are determined to be candidate buildings in which the mobile device resides, (i) determining a representative altitude of the mobile device and calibrating the pressure sensor of the mobile device using the determined representative altitude, or (ii) determining that the representative altitude of the mobile device cannot be determined for use in calibrating the pressure sensor comprises;

accessing information for the particular building or for each of the candidate buildings to determine if that building is a single-story building;

determining if the particular building or each of the candidate buildings is a single-story building;

determining that the location of the mobile device is on a ground-level floor of the particular building and calibrating the pressure sensor of the mobile device using a representative altitude of the mobile device that is equal to a representative ground-level altitude of the particular building if the particular building is a single-story building, or determining that the location of the mobile device is on a ground-level floor of one of the candidate buildings and calibrating the pressure sensor of the mobile device using a representative altitude of the mobile device that is equal to a representative ground-level altitude of the candidate buildings if each of the candidate buildings is a single-story building or if a number of the candidate buildings that are single-story buildings exceeds a threshold amount; and

determining that the location of the mobile device cannot be determined to be on a ground-level floor of the particular building and determining that a representative altitude of the mobile device cannot be determined as a representative ground-level altitude of the particular building for use in calibrating the pressure sensor if the particular building is not a single-story building, or determining that the location of the mobile device cannot be determined to be on a ground-level floor of one of the candidate buildings and determining that a representative altitude of the mobile device cannot be determined as a representative ground-level altitude of the candidate buildings for use in calibrating the pressure sensor if any of the candidate buildings is not a single-story building or if the number of the candidate buildings that are single-story buildings is less than the threshold amount.

11. The method of claim 10, wherein determining if the particular building or each of the candidate buildings is a single-story building comprises:

for the particular building or for each of the candidate buildings;

retrieving one or more floor heights or floor labels for that building from a database;

determining if the one or more retrieved floor heights or floor labels for that building specify (i) only a ground-level floor height or only a ground-level floor for that building or (ii) more than one floor height or more than one floor for that building;

if the one or more retrieved floor heights or floor labels for that building specify only a ground-level floor height or only a ground-level floor for that building, determining that building is a single-story building; and

if the one or more retrieved floor heights or floor labels for that building specify more than one floor height or more than one floor for that building, determining that building is not a single-story building.

12. The method of claim 10, wherein determining if the particular building or each of the candidate buildings is a single-story building comprises:

for the particular building or for each of the candidate buildings;

retrieving a height or altitude for that building from a database;

determining if the height or altitude indicates that building is more likely to be a single-story building or to not be a single-story building;

if the height or altitude indicates that building is more likely to be a single-story building than to not be a single-story building, determining that building is a single-story building; and

if the height or altitude indicates that building is more likely to not be a single-story building than to be a single-story building, determining that building is not a single-story building.

13. The method of claim 12, wherein determining if the height or altitude indicates that building is more likely to be a single-story building or to not be a single-story building comprises:

determining if the retrieved height of that building is greater than a threshold maximum height or determining if the retrieved altitude of that building is greater than a threshold maximum altitude;

if the retrieved height of that building is not greater than the threshold maximum height, determining that the height indicates that building is more likely to be a single-story building than to not be a single-story building, or if the retrieved altitude of that building is not greater than the threshold maximum altitude, determining that the altitude indicates that building is more likely to be a single-story building than not a single-story building; and

if the retrieved height of that building is greater than the threshold maximum height, determining that the height indicates that building is more likely to not be a single-story building than to be a single-story building, or if the retrieved altitude of that building is greater than the threshold maximum altitude, determining that the altitude indicates that building is more likely to not be a single-story building than to be a single-story building.

14. The method of claim 10, wherein the location of the mobile device is determined to be on a ground-level floor of one of the candidate buildings and the pressure sensor of the mobile device is calibrated using a representative altitude of the mobile device that is equal to a representative ground-level altitude of the candidate buildings if each of the candidate buildings is a single-story building, and wherein the location of the mobile device cannot be determined to be on a ground-level floor of one of the candidate buildings and a representative altitude of the mobile device cannot be determined as a representative ground-level altitude of the candidate buildings for use in calibrating the pressure sensor if any of the candidate buildings is not a single-story building.

15. The method of claim 10, wherein the location of the mobile device is determined to be on a ground-level floor of one of the candidate buildings and the pressure sensor of the mobile device is calibrated using a representative altitude of the mobile device that is equal to a representative ground-level altitude of the candidate buildings if the number of the candidate buildings that are single-story buildings exceeds the threshold amount, and wherein the location of the mobile device cannot be determined to be on a ground-level floor of one of the candidate buildings and a representative altitude of the mobile device cannot be determined as a representative ground-level altitude of the candidate buildings for use in calibrating the pressure sensor if the number of the candidate buildings that are single-story buildings is less than the threshold amount.

16. One or more non-transitory machine-readable media embodying program instructions that, when executed by one or more machines, cause the one or more machines to implement a method for determining an indoor or outdoor location of a mobile device, wherein the method comprises:

determining a user footprint;

identifying each building with a building footprint that at least partially overlaps with the user footprint; and

determining, based on the user footprint and the building footprints of the identified buildings, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides,

wherein determining, based on the user footprint and building footprints of the identified buildings, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides comprises;

determining an average building footprint of the building footprints of the identified buildings;

determining a first ratio representing an amount of the user footprint that is occupied by the building footprints of the identified buildings;

determining a second ratio representing a comparative size of the user footprint and the average building footprint; and

determining, based on the value of the first ratio and the value of the second ratio, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides.

17. The one or more non-transitory machine-readable media of claim 16, wherein determining, based on the value of the first ratio and the value of the second ratio, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides comprises:

determining if the first ratio is zero;

if the first ratio is not zero, determining a first relationship specifying if the first ratio is less than or greater than a first threshold value, and determining a second relationship specifying if the second ratio is less than or greater than a second threshold value; and

determining, based on whether the first ratio is zero or based on the first and second relationships, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides.

18. The one or more non-transitory machine-readable media of claim 17, wherein determining, based on whether the first ratio is zero or based on the first and second relationships, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides comprises:

determining that the mobile device does not reside inside any building when the first ratio is zero;

determining that the mobile device resides inside a building from the identified buildings with a building footprint that overlaps the user footprint more than any other building footprint of any other identified building when the first relationship specifies the first ratio is greater than the first threshold value, and the second relationship specifies the second ratio is not greater than the second threshold value; and

determining that the identified buildings are candidate buildings that include a building in which the mobile device resides (i) when the first relationship specifies the first ratio is greater than the first threshold value, and the second relationship specifies the second ratio is greater than the second threshold value, (ii) when the first relationship specifies the first ratio is not greater than the first threshold value, and the second relationship specifies the second ratio is not greater than the second threshold value, or (iii) when the first relationship specifies the first ratio is not greater than the first threshold value, and the second relationship specifies the second ratio is greater than the second threshold value.

19. The one or more non-transitory machine-readable media of claim 17, wherein determining, based on whether the first ratio is zero or based on the first and second relationships, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides comprises:

determining that the mobile device does not reside inside any building when the first ratio is zero.

20. The one or more non-transitory machine-readable media of claim 17, wherein determining, based on whether the first ratio is zero or based on the first and second relationships, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides comprises:

determining that the mobile device resides inside a building from the identified buildings with a building footprint that overlaps the user footprint more than any other building footprint of any other identified building when the first relationship specifies the first ratio is greater than the first threshold value, and the second relationship specifies the second ratio is not greater than the second threshold value.

21. The one or more non-transitory machine-readable media of claim 17, wherein determining, based on whether the first ratio is zero or based on the first and second relationships, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides comprises:

determining that the identified buildings are candidate buildings that include a building in which the mobile device resides (i) when the first relationship specifies the first ratio is greater than the first threshold value, and the second relationship specifies the second ratio is greater than the second threshold value, (ii) when the first relationship specifies the first ratio is not greater than the first threshold value, and the second relationship specifies the second ratio is not greater than the second threshold value, or (iii) when the first relationship specifies the first ratio is not greater than the first threshold value, and the second relationship specifies the second ratio is greater than the second threshold value.

22. The one or more non-transitory machine-readable media of claim 17, wherein determining, based on whether the first ratio is zero or based on the first and second relationships, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides comprises:

determining that the mobile device does not reside inside any building when the first ratio is zero;

determining that the mobile device resides inside a building from the identified buildings with a building footprint that overlaps the user footprint more than any other building footprint of any other identified building when the first relationship specifies the first ratio is greater than the first threshold value, and the second relationship specifies the second ratio is not greater than the second threshold value;

determining that the mobile device resides inside one of the identified buildings when the first relationship specifies the first ratio is greater than the first threshold value, and the second relationship specifies the second ratio is greater than the second threshold value; and

determining that the mobile device does not reside inside any building when (i) the first relationship specifies the first ratio is not greater than the first threshold value, and the second relationship specifies the second ratio is not greater than the second threshold value, or (ii) the first relationship specifies the first ratio is not greater than the first threshold value, and the second relationship specifies the second ratio is greater than the second threshold value.

23. The one or more non-transitory machine-readable media of claim 17, wherein determining, based on whether the first ratio is zero or based on the first and second relationships, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides comprises:

determining that the mobile device resides inside one of the identified buildings when the first relationship specifies the first ratio is greater than the first threshold value, and the second relationship specifies the second ratio is greater than the second threshold value.

24. The one or more non-transitory machine-readable media of claim 17, wherein determining, based on whether the first ratio is zero or based on the first and second relationships, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides comprises:

determining that the mobile device does not reside inside any building when (i) the first relationship specifies the first ratio is not greater than the first threshold value, and the second relationship specifies the second ratio is not greater than the second threshold value, or (ii) the first relationship specifies the first ratio is not greater than the first threshold value, and the second relationship specifies the second ratio is greater than the second threshold value.

25. One or more non-transitory machine-readable media embodying program instructions that, when executed by one or more machines, cause the one or more machines to implement a method for determining an indoor or outdoor location of a mobile device, wherein the method comprises:

determining a user footprint;

identifying each building with a building footprint that at least partially overlaps with the user footprint; and

determining, based on the user footprint and the building footprints of the identified buildings, that (i) the mobile device does not reside inside any building, (ii) the mobile device resides inside a particular building from the identified buildings, or (iii) that one or more of the identified buildings are candidate buildings that include a building in which the mobile device resides;

if the mobile device is determined to not reside inside any building, calibrating a pressure sensor of the mobile device using one or more altitudes of outdoor ground terrain within the user footprint if the one or more altitudes are all within a threshold amount of altitude from each other; and

if the mobile device is determined to reside inside a particular building from the identified buildings or if one or more of the identified buildings are determined to be candidate buildings in which the mobile device resides, (i) determining a representative altitude of the mobile device and calibrating the pressure sensor of the mobile device using the determined representative altitude, or (ii) determining that the representative altitude of the mobile device cannot be determined for use in calibrating the pressure sensor,

wherein when the mobile device is determined to reside inside a particular building from the identified buildings or when one or more of the identified buildings are determined to be candidate buildings in which the mobile device resides, (i) determining a representative altitude of the mobile device and calibrating the pressure sensor of the mobile device using the determined representative altitude, or (ii) determining that the representative altitude of the mobile device cannot be determined for use in calibrating the pressure sensor comprises;

accessing information for the particular building or for each of the candidate buildings to determine if that building is a single-story building;

determining if the particular building or each of the candidate buildings is a single-story building;

determining that the location of the mobile device is on a ground-level floor of the particular building and calibrating the pressure sensor of the mobile device using a representative altitude of the mobile device that is equal to a representative ground-level altitude of the particular building if the particular building is a single-story building, or determining that the location of the mobile device is on a ground-level floor of one of the candidate buildings and calibrating the pressure sensor of the mobile device using a representative altitude of the mobile device that is equal to a representative ground-level altitude of the candidate buildings if each of the candidate buildings is a single-story building or if a number of the candidate buildings that are single-story buildings exceeds a threshold amount; and

determining that the location of the mobile device cannot be determined to be on a ground-level floor of the particular building and determining that a representative altitude of the mobile device cannot be determined as a representative ground-level altitude of the particular building for use in calibrating the pressure sensor if the particular building is not a single-story building, or determining that the location of the mobile device cannot be determined to be on a ground-level floor of one of the candidate buildings and determining that a representative altitude of the mobile device cannot be determined as a representative ground-level altitude of the candidate buildings for use in calibrating the pressure sensor if any of the candidate buildings is not a single-story building or if the number of the candidate buildings that are single-story buildings is less than the threshold amount.

26. The one or more non-transitory machine-readable media of claim 25, wherein determining if the particular building or each of the candidate buildings is a single-story building comprises:

for the particular building or for each of the candidate buildings;

retrieving one or more floor heights or floor labels for that building from a database;

determining if the one or more retrieved floor heights or floor labels for that building specify (i) only a ground-level floor height or only a ground-level floor for that building or (ii) more than one floor height or more than one floor for that building;

if the one or more retrieved floor heights or floor labels for that building specify only a ground-level floor height or only a ground-level floor for that building, determining that building is a single-story building; and

if the one or more retrieved floor heights or floor labels for that building specify more than one floor height or more than one floor for that building, determining that building is not a single-story building.

27. The one or more non-transitory machine-readable media of claim 25, wherein determining if the particular building or each of the candidate buildings is a single-story building comprises:

for the particular building or for each of the candidate buildings;

retrieving a height or altitude for that building from a database;

determining if the height or altitude indicates that building is more likely to be a single-story building or to not be a single-story building;

if the height or altitude indicates that building is more likely to be a single-story building than to not be a single-story building, determining that building is a single-story building; and

if the height or altitude indicates that building is more likely to not be a single-story building than to be a single-story building, determining that building is not a single-story building.

28. The one or more non-transitory machine-readable media of claim 27, wherein determining if the height or altitude indicates that building is more likely to be a single-story building or to not be a single-story building comprises:

determining if the retrieved height of that building is greater than a threshold maximum height or determining if the retrieved altitude of that building is greater than a threshold maximum altitude;

if the retrieved height of that building is not greater than the threshold maximum height, determining that the height indicates that building is more likely to be a single-story building than to not be a single-story building, or if the retrieved altitude of that building is not greater than the threshold maximum altitude, determining that the altitude indicates that building is more likely to be a single-story building than not a single-story building; and

if the retrieved height of that building is greater than the threshold maximum height, determining that the height indicates that building is more likely to not be a single-story building than to be a single-story building, or if the retrieved altitude of that building is greater than the threshold maximum altitude, determining that the altitude indicates that building is more likely to not be a single-story building than to be a single-story building.

29. The one or more non-transitory machine-readable media of claim 25, wherein the location of the mobile device is determined to be on a ground-level floor of one of the candidate buildings and the pressure sensor of the mobile device is calibrated using a representative altitude of the mobile device that is equal to a representative ground-level altitude of the candidate buildings if each of the candidate buildings is a single-story building, and wherein the location of the mobile device cannot be determined to be on a ground-level floor of one of the candidate buildings and a representative altitude of the mobile device cannot be determined as a representative ground-level altitude of the candidate buildings for use in calibrating the pressure sensor if any of the candidate buildings is not a single-story building.

30. The one or more non-transitory machine-readable media of claim 25, wherein the location of the mobile device is determined to be on a ground-level floor of one of the candidate buildings and the pressure sensor of the mobile device is calibrated using a representative altitude of the mobile device that is equal to a representative ground-level altitude of the candidate buildings if the number of the candidate buildings that are single-story buildings exceeds the threshold amount, and wherein the location of the mobile device cannot be determined to be on a ground-level floor of one of the candidate buildings and a representative altitude of the mobile device cannot be determined as a representative ground-level altitude of the candidate buildings for use in calibrating the pressure sensor if the number of the candidate buildings that are single-story buildings is less than the threshold amount.