Characterizing and using building weather profile parameters

Abstract

Determining building weather profile parameters, and correcting an estimated altitude of a receiver using the building weather profile parameters. Systems and methods for estimating an altitude of a receiver using building weather profile parameters may identify one or more weather profile parameters for a building, determine an initial estimate of a receiver's altitude at a floor inside the building, and use the initial estimate and the identified weather profile parameters to determine a corrected estimate of the receiver's altitude at the floor.

1 . A method for estimating an altitude of a receiver using building weather profile parameters, the method comprising:
 identifying one or more weather profile parameters for a building;   determining an initial estimate of a receiver's altitude at a floor inside the building; and   using the initial estimate and the identified weather profile parameters to determine a corrected estimate of the receiver's altitude at the floor.   
     
     
         2 . The method of  claim 1 , wherein identifying the one or more weather profile parameters for the building comprises:
 determining indoor pressures at different altitudes of the building;   determining indoor temperatures at the different altitudes of the building;   determining a pressure difference between the determined indoor pressure and a corresponding outdoor pressure for each of the different altitudes;   determining a temperature difference between the determined indoor temperature and a corresponding outdoor temperature for each of the different altitudes;   storing the determined pressure differences and the determined temperature differences;   generating one or more weather profile parameters associated with the building using the determined pressure differences and the determined temperature differences; and   storing the one or more weather profile parameters.   
     
     
         3 . The method of  claim 2 , wherein the pressure differences and the temperature differences are determined by:
 determining an outdoor pressure;   determining an outdoor temperature;   determining the corresponding outdoor pressure for each of the different altitudes using the determined outdoor pressure; and   determining the corresponding outdoor temperature for each of the different altitudes using the determined outdoor temperature.   
     
     
         4 . The method of  claim 2 , wherein the pressure differences and the temperature differences are determined by:
 determining a first indoor pressure and a first indoor temperature at a first altitude of the different altitudes when a first receiver is at the first altitude;   determining a first outdoor pressure and a first outdoor temperature at the first altitude;   generating, using the first outdoor pressure and the first indoor pressure, an estimate of the first altitude;   identifying an expected altitude of a first floor of the building at which the first receiver is located when the first receiver is at the first altitude;   determining an altitude difference between the expected altitude of the first floor and the estimate of the first altitude;   determining a first pressure difference between the first indoor pressure and a first corresponding outdoor pressure for the first altitude using the altitude difference; and   determining a first temperature difference between the first outdoor temperature and the first indoor temperature.   
     
     
         5 . The method of  claim 4 , wherein determining the pressure differences and the temperature differences further comprises:
 determining a second indoor pressure and a second indoor temperature at a second altitude of the different altitudes when a second receiver is at the second altitude;   determining a second outdoor pressure and a second outdoor temperature at the second altitude;   generating, using the second outdoor pressure and the second indoor pressure, an estimate of the second altitude;   identifying an expected altitude of a second floor of the building at which the second receiver is located when the second receiver is at the second altitude;   determining an altitude difference between the expected altitude of the second floor and the estimate of the second altitude;   determining a second pressure difference between the second indoor pressure and a second corresponding outdoor pressure for the second altitude using the altitude difference; and   determining a second temperature difference between the second outdoor temperature and the second indoor temperature.   
     
     
         6 . The method of  claim 5 , wherein the first receiver and the second receiver are the same receiver. 
     
     
         7 . The method of  claim 2 , wherein generating the one or more weather profile parameters associated with the building comprises:
 generating a linear fit representing the determined pressure differences as a function of altitude;   estimating a plurality of fit parameters using the linear fit, wherein a first fit parameter represents the slope of the linear fit and a second fit parameter represents the y-intercept of the linear fit; and   determining the one or more weather profile parameters associated with the building using the plurality of fit parameters.   
     
     
         8 . The method of  claim 7 , wherein the one or more weather profile parameters include a first weather profile parameter that represents a volume of air that passes through a surface boundary of the building, a second weather profile parameter that represents HVAC performance of the building, and a third weather profile parameter that represents building air leakage as a function of building height. 
     
     
         9 . The method of  claim 8 , wherein determining the one or more weather profile parameters associated with the building comprises:
 identifying two or more sets of fit parameters, wherein each set of fit parameters includes the first fit parameter and the second fit parameter;   generating two or more ratios using the two or more sets of fit parameters and two or more temperature differences;   determining the first weather profile parameter by averaging the two or more ratios; and   determining the second weather profile parameter and the third weather profile parameter by fitting a line to a distribution of each two or more sets of fit parameters.   
     
     
         10 . The method of  claim 9 , wherein the y-intercept of the fitted line corresponds to the second weather profile parameter, and the slope of the fitted line corresponds to the third weather profile parameter. 
     
     
         11 . The method of  claim 1 , wherein identifying the one or more weather profile parameters for the building comprises:
 determining an estimated position of the receiver;   identifying the building using the estimated position; and   identifying, after identifying the building, the one or more weather profile parameters from a database.   
     
     
         12 . The method of  claim 1 , wherein determining an initial estimated altitude of a receiver inside the building comprises:
 measuring an indoor pressure using a pressure sensor of the receiver when the receiver is at the floor;   determining outdoor pressure; and   determining the initial estimated altitude of the receiver using the measured indoor pressure and the determined outdoor pressure.   
     
     
         13 . The method of  claim 1 , wherein using the initial estimate of receiver's altitude and the identified weather profile parameters to determine the corrected estimate of the receiver's altitude at the floor comprises:
 determining a first value by dividing 1) product of an acceleration due to gravity, a molar mass of dry air and a measured indoor pressure by 2) a product of a universal gas constant and a reference outdoor temperature;   determining a second value by multiplying the first value by the initial estimate of the receiver's altitude;   determining a third value by multiplying a first identified weather profile parameter by an inverted temperature difference and a second identified weather profile parameter;   determining a difference of the second value and the third value;   determining a fourth value by adding a third identified weather profile parameter to the difference;   determining a third product by multiplying the first identified weather profile parameter by the inverted temperature difference;   determining a fifth value by subtracting the third product from the first value; and   determining the corrected estimate of the receiver's altitude by dividing the fourth value by the fifth value.   
     
     
         14 . The method of  claim 2 , wherein each of the determined pressure differences and the determined temperature differences are stored in association with one or more of a time, a date, an altitude, or a building identifier. 
     
     
         15 . The method of  claim 2 , wherein the one or more weather profile parameters are stored in association with one or more of a time, a date, an altitude, or a building identifier. 
     
     
         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 the method of  claim 1 . 
     
     
         17 . A system for estimating an altitude of a receiver using building weather profile parameters, the system comprising:
 an antenna module;   a sensor module;   a position information determination module;   a position determination module;   an initial altitude estimation module;   a weather profile parameter identification module; and   an altitude correction module,   wherein the antenna module is coupled to the position information determination module,   wherein the position information determination module is coupled to the position determination module,   wherein the position determination module is coupled to the weather profile parameter identification module,   wherein the weather profile parameter identification module is coupled to the altitude correction module,   wherein the sensor module is coupled to the initial altitude estimation module, and   wherein the initial altitude estimation module is coupled to the altitude correction module.   
     
     
         18 . The system of  claim 17 :
 wherein the sensor module is operable to determine an indoor pressure and an indoor temperature at a floor within a building,   wherein the position information determination module is operable to determine position information,   wherein the position determination module is operable to use the position information to determine an estimated position of the receiver,   wherein the initial altitude estimation module is operable to determine an initial estimate of the receiver's altitude at the floor within the building,   wherein the weather profile parameter identification module is operable to identify one or more weather profile parameters from a database, and   wherein the altitude correction module is operable to use the initial estimate and the identified weather profile parameters to determine a corrected estimate of the receiver's altitude at the floor.   
     
     
         19 . The system of  claim 17 , the system comprising:
 a pressure and temperature difference determination module;   a pressure and temperature difference storage module;   a weather profile parameter generation module; and   a weather profile parameter storage module,   wherein the sensor module is coupled to the pressure and temperature difference determination module,   wherein the pressure and temperature difference determination module is coupled to the pressure and temperature difference storage module,   wherein the pressure and temperature difference storage module is coupled to the weather profile parameter generation module, and   wherein the weather profile parameter generation module is coupled to the weather profile parameter storage module.   
     
     
         20 . The system of  claim 19 :
 wherein the sensor module is operable to determine an indoor pressure and an indoor temperature,   wherein the pressure and temperature difference determination module is operable to 1) determine a pressure difference between the indoor pressure and a corresponding outdoor pressure for an altitude, and 2) determine a temperature difference between the indoor temperature and an outdoor temperature for the altitude;   wherein the pressure and temperature difference storage module is operable to store the determined pressure difference and to store the determined temperature difference,   wherein the weather profile parameter generation module is operable to generate one or more weather profile parameters using the determined pressure difference and the determined temperature difference, and   wherein the weather profile parameter storage module is operable to store the one or more weather profile parameters.