Relative Elevation Determination Using GPS and RF Ranging
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Solution Overview
Problem
Existing location determination methods for wireless communication devices, such as radios, face challenges in accurately calculating the z-position in GPS-equipped devices within buildings, as satellite navigation systems provide inaccurate z-coordinate calculations, limiting the precision to a specific quadrant rather than a specific floor.
Innovation Solution
A method involving determining the (x,y) positions of multiple wireless communication devices using GPS and radio frequency ranging to calculate the distance and relative elevational differential between them, allowing for accurate determination of the z-position by applying the Pythagorean theorem to the horizontal distance and absolute distance, and using network aiding for enhanced precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GPS satellite navigation system is used to determine location, then (x,y) position can be obtained, but z-position calculation is inaccurate
Solution Approach 1:
The patent introduces an intermediary device (second wireless communication device) that acts as a mediator between the GPS system and the target device. This intermediary has a known precise location and serves as a reference point for calculating the target device's z-position through distance measurements, bypassing the unreliable GPS z-coordinate
Solution Approach 2:
The patent transitions from relying solely on GPS three-dimensional coordinates (where z is inaccurate) to using horizontal distance in the x-y plane combined with slant range distance to calculate vertical separation. This dimensional approach separates the accurate horizontal positioning from the derived vertical positioning
2Measurement precision
If triangulation method is used with multiple radios, then location can be determined, but device placement is difficult and complex
Solution Approach 1:
The second wireless communication device serves as a portable intermediary that can be placed at any location with known coordinates. This eliminates the need for complex fixed infrastructure placement while maintaining triangulation accuracy, as the intermediary's position can be determined via GPS or other positioning methods
Solution Approach 2:
The intermediary device performs multiple functions: it serves as a reference point for distance measurement, provides a known location anchor, and enables z-position calculation. This multi-functionality reduces the need for specialized equipment while maintaining measurement precision
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables precise determination of the z-position of wireless communication devices, including identifying the floor in a building, improving location accuracy for critical applications like firefighting and asset tracking, even in urban environments.
Implementation Method 1
the distance between the first wireless communication device and the second wireless communication device is determined using radio frequency ranging
Implementation Method 2
determining a relative elevational differential between the first wireless communication device and the second wireless communication device based on, (i) the determined (x,y) positions of the first and second wireless communication devices, and (ii) the determined distance between the first and second wireless communication devices
Data Source
AI summary
A system and method are disclosed for determining a position of a wireless communication device. A method includes determining a respective (x,y) position of two wireless communication devices, determining a distance between the two wireless communication devices, and determining a relative elevational differential between the two wireless communication devices. The relative elevational differential is determined based on the determined (x,y) positions of the two wireless communication devices and the determined distance between the first and second wireless communication devices. The (x,y) positions may be determined using GPS receivers incorporated in the wireless communication devices. Determining the distance between the devices may be accomplished using RF ranging. The relative elevational differential may be derived using the Pythagorean theorem.