Signal Source Position Estimation Correcting Altitude and Pitch Errors
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Solution Overview
Problem
Current methods for estimating the position of a signal source in electronic warfare, particularly using a mobile sensor, suffer from errors due to the curvature of the Earth and neglect the pitch of an aircraft and elevation of the signal source, leading to inaccurate positional estimates.
Innovation Solution
A method that corrects altitude errors in position data by determining a direction vector for the signal source and sensors, using a least square error method to minimize errors, and converting the position into latitude, longitude, and altitude coordinates, considering the Earth's curvature and aircraft attitude.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a planar coordinate system is used for position estimation, then the calculation is simple and fast, but positional distortion occurs due to Earth's curvature
Solution Approach 1:
The patent applies a spherical coordinate system instead of a planar coordinate system to account for Earth's curvature. This allows the position estimation to maintain accuracy over long distances by using spherical geometry for triangulation calculations, while still providing computational efficiency through established spherical math algorithms.
2Device complexity
If only planar coordinates are used for triangulation, then the method is simple, but altitude errors and pitch errors are not corrected
Solution Approach 1:
The patent extends the position estimation from two-dimensional planar coordinates to three-dimensional spherical coordinates by incorporating altitude information. This dimensional expansion allows the system to correct for pitch errors and altitude errors by adding the vertical dimension to the triangulation calculation, thereby improving accuracy without excessive complexity.
Solution Approach 2:
The patent modifies the position estimation parameters by introducing altitude correction terms and pitch angle adjustments into the triangulation formula. These parameter changes allow the system to compensate for errors in altitude and pitch measurements, improving overall position estimation accuracy while maintaining a relatively simple calculation structure.
3Area of stationary object
If the distance between mobile sensor and signal source is large, then coverage area increases, but curvature errors increase
Solution Approach 1:
The patent uses spherical geometry for position estimation, which naturally accommodates large distances over the Earth's surface. By using spherical law of cosines and spherical trigonometry instead of planar Euclidean geometry, the system maintains accurate position estimation even when the mobile sensor is far from the signal source, thus expanding coverage area without sacrificing precision.
Data Source
AI summary
Provided is a technology for increasing accuracy of position estimation by estimating a position of a signal source based on an error due to altitudes of a sensor and a signal source and an error due to a pitch of an aircraft as well as an error due to curvature of the earth. At this time, a position estimation method may include receiving measurement data from a plurality of sensors, estimating first position data of the signal source based on the measurement data, identifying an altitude error of the first position data, and estimating second position data that is data obtained by correcting the first position data based on the altitude error.