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US 10,649,090 B2Granted
Wide area positioning system
AssigneeNextNav, LLC
InventorsArun Raghupathy, Subramanian S Meiyappan, Thomas Wolf
Life of this patent
Estimating the term…
Abstract
Positioning systems and methods for estimating an altitude of a receiver. In some embodiments, pressure and temperature information from a network of sensors is received by the receiver, and the pressure and temperature information from the network of sensors is used along with pressure information measured at a position of the receiver to estimate the altitude of the receiver.
Claims20
A method for estimating an altitude of a receiver, the method comprising:
- computing, using one or more processors, an estimate of the altitude of the receiver using
- (a) a measurement of pressure measured by a pressure sensor of the receiver at a location of the receiver,
- (b) a measurement of temperature not measured at the location of the receiver, and
- (c) a first reference pressure determined for a reference altitude using
- (i) a first pressure measurement measured by a first atmospheric reference sensor at a first known reference location, and
- (ii) a first altitude of the first known reference location,
- wherein the estimate of the altitude of the receiver is determined using any of the following mathematical relationships:
- (i) −(R*T/g)*ln(P/P_0), where P is the measurement of pressure measured by the pressure sensor of the receiver, P_0 is a reference pressure estimate that is based on the first reference pressure, T is the measurement of temperature, g is acceleration due to gravity, and R is a gas constant value, wherein the reference pressure estimate is an estimated pressure at sea-level;
- or
- (ii) z_2−(R*T/g)*ln(P_1/P_2), where P_1 is the measurement of pressure measured by the pressure sensor of the receiver, P_2 is the reference pressure estimate that is based on the first reference pressure, z_2 is the reference altitude, T is the measurement of temperature, g is the acceleration due to gravity, and R is the gas constant, wherein the reference pressure estimate is an estimated pressure at the reference altitude.
7 more elements
A method for estimating an altitude of a receiver, the method comprising:
- computing, using one or more processors, an estimate of the altitude of the receiver using
- (a) a measurement of pressure measured by a pressure sensor of the receiver at a location of the receiver,
- (b) a measurement of temperature not measured at the location of the receiver, and
- (c) a first reference pressure determined for a reference altitude using
- (i) a first pressure measurement measured by a first atmospheric reference sensor at a first known reference location, and
- (ii) a first altitude of the first known reference location;
- determining that the receiver is moving at a high velocity;
- and
- while the receiver is moving at the high velocity, not estimating any altitude of the receiver using pressure information.
6 more elements
A method for estimating an altitude of a receiver, the method comprising:
- computing, using one or more processors, an estimate of the altitude of the receiver using
- (a) a measurement of pressure measured by a pressure sensor of the receiver at a location of the receiver,
- (b) a measurement of temperature not measured at the location of the receiver, and
- (c) a first reference pressure determined for a reference altitude using
- (i) a first pressure measurement measured by a first atmospheric reference sensor at a first known reference location, and
- (ii) a first altitude of the first known reference location;
- determining that the location is a known location with a known altitude;
- determining a deviation of the estimate of the altitude from the known altitude;
- and
- based on the deviation, calibrating the pressure sensor of the receiver,
- wherein the deviation is stored among other deviations of other estimated altitudes from the known altitude, wherein the other estimated altitudes are based on other measurements of pressure by the pressure sensor of the receiver when the receiver was at the known location at different times, and wherein calibrating the pressure sensor of the receiver is based on the other deviations.
8 more elements
A method for estimating an altitude of a receiver, the method comprising:
- computing, using one or more processors, an estimate of the altitude of the receiver using
- (a) a measurement of pressure measured by a pressure sensor of the receiver at a location of the receiver,
- (b) a measurement of temperature not measured at the location of the receiver, and
- (c) a first reference pressure determined for a reference altitude using
- (i) a first pressure measurement measured by a first atmospheric reference sensor at a first known reference location, and
- (ii) a first altitude of the first known reference location;
- determining that the location is a known location with a known altitude;
- determining a deviation of the estimate of the altitude from the known altitude;
- and
- based on the deviation, calibrating the pressure sensor of the receiver,
- wherein the location is a known location at which the receiver is placed at night, and wherein the known altitude is a stored altitude value.
8 more elements
One or more non-transitory computer-readable media embodying program instructions that, when executed by one or more processors, cause the one or more processors to perform a method for estimating an altitude of a receiver, the method comprising:
- computing, using one or more processors, an estimate of the altitude of the receiver using
- (a) a measurement of pressure measured by a pressure sensor of the receiver at a location of the receiver,
- (b) a measurement of temperature not measured at the location of the receiver, and
- (c) a first reference pressure determined for a reference altitude using
- (i) a first pressure measurement measured by a first atmospheric reference sensor at a first known reference location, and
- (ii) a first altitude of the first known reference location,
- wherein the estimate of the altitude of the receiver is determined using any of the following mathematical relationships:
- (iii) −(R*T/g)*ln(P/P_0), where P is the measurement of pressure measured by the pressure sensor of the receiver, P_0 is a reference pressure estimate that is based on the first reference pressure, T is the measurement of temperature, g is acceleration due to gravity, and R is a gas constant value, wherein the reference pressure estimate is an estimated pressure at sea-level;
- or
- (iv) z_2−(R*T/g)*ln(P_1/P_2), where P_1 is the measurement of pressure measured by the pressure sensor of the receiver, P_2 is the reference pressure estimate that is based on the first reference pressure, z_2 is the reference altitude, T is the measurement of temperature, g is the acceleration due to gravity, and R is the gas constant, wherein the reference pressure estimate is an estimated pressure at the reference altitude.
7 more elements
One or more non-transitory computer-readable media embodying program instructions that, when executed by one or more processors, cause the one or more processors to perform a method for estimating an altitude of a receiver, the method comprising:
- computing, using one or more processors, an estimate of the altitude of the receiver using
- (a) a measurement of pressure measured by a pressure sensor of the receiver at a location of the receiver,
- (b) a measurement of temperature not measured at the location of the receiver, and
- (c) a first reference pressure determined for a reference altitude using
- (i) a first pressure measurement measured by a first atmospheric reference sensor at a first known reference location, and
- (ii) a first altitude of the first known reference location;
- determining that the receiver is moving at a high velocity;
- and
- while the receiver is moving at the high velocity, not estimating any altitude of the receiver using pressure information.
6 more elements
One or more non-transitory computer-readable media embodying program instructions that, when executed by one or more processors, cause the one or more processors to perform a method for estimating an altitude of a receiver, the method comprising:
- computing, using one or more processors, an estimate of the altitude of the receiver using
- (a) a measurement of pressure measured by a pressure sensor of the receiver at a location of the receiver,
- (b) a measurement of temperature not measured at the location of the receiver, and
- (c) a first reference pressure determined for a reference altitude using
- (i) a first pressure measurement measured by a first atmospheric reference sensor at a first known reference location, and
- (ii) a first altitude of the first known reference location;
- determining that the location is a known location with a known altitude;
- determining a deviation of the estimate of the altitude from the known altitude;
- and
- based on the deviation, calibrating the pressure sensor of the receiver,
- wherein the deviation is stored among other deviations of other estimated altitudes from the known altitude, wherein the other estimated altitudes are based on other measurements of pressure by the pressure sensor of the receiver when the receiver was at the known location at different times, and wherein calibrating the pressure sensor of the receiver is based on the other deviations.
8 more elements
One or more non-transitory computer-readable media embodying program instructions that, when executed by one or more processors, cause the one or more processors to perform a method for estimating an altitude of a receiver, the method comprising:
- computing, using one or more processors, an estimate of the altitude of the receiver using
- (a) a measurement of pressure measured by a pressure sensor of the receiver at a location of the receiver,
- (b) a measurement of temperature not measured at the location of the receiver, and
- (c) a first reference pressure determined for a reference altitude using
- (i) a first pressure measurement measured by a first atmospheric reference sensor at a first known reference location, and
- (ii) a first altitude of the first known reference location;
- determining that the location is a known location with a known altitude;
- determining a deviation of the estimate of the altitude from the known altitude;
- and
- based on the deviation, calibrating the pressure sensor of the receiver,
- wherein the location is a known location at which the receiver is placed at night, and wherein the known altitude is a stored altitude value.
8 more elements
Dependencies are inferred from the claim text.