Navigation system with minimal on-board processing

A method of determining a position estimate of an object, the method comprising:

• providing at least one processor configured to execute instructions to perform a process of generating a position estimate of an object in three dimensions, the process comprising:
• integrating an acceleration estimate in each of three dimensions to determine an integrated acceleration estimate for each of the dimensions;
• subtracting a GPS velocity in each of the dimensions from the integrated acceleration estimate for each of the dimensions to determine a velocity noise error in each dimension;
• filtering the velocity noise error in each dimension;
• adding the filtered velocity noise error to the integrated acceleration estimate in each dimension to obtain a velocity estimate in each dimension;
• integrating the velocity estimate in each dimension to determine an integrated velocity estimate in each dimension;
• subtracting a GPS position in each dimension from the integrated velocity estimate in each dimension to determine a position noise error in each dimension;
• filtering the position noise error in each dimension;
• and
• adding the filtered position noise error in each dimension to the integrated velocity estimate to obtain a position estimate in each dimension.

A non-transitory machine readable medium having instructions stored thereon executable by a processor to perform a method of generating a position estimate of an object, the method comprising:

• integrating an acceleration estimate to determine an integrated acceleration estimate;
• subtracting a GPS velocity from the integrated acceleration estimate to determine a velocity noise error;
• filtering the velocity noise error;
• adding the filtered velocity noise error to the integrated acceleration estimate to obtain a velocity estimate;
• integrating the velocity estimate to determine a position;
• subtracting a GPS position from the integrated velocity estimate to determine a position noise error;
• filtering the position noise error;
• and
• adding the filtered position noise error to the integrated velocity estimate to obtain a position estimate.

A position determining device to estimate the position of an object in three dimensions, comprising:

• means for determining an acceleration estimate;
• means for integrating the acceleration estimate to determine an integrated acceleration estimate;
• means for subtracting a GPS velocity from the integrated acceleration estimate to determine a velocity noise error;
• means for filtering the velocity noise error;
• means for adding the filtered velocity noise error to the integrated acceleration estimate to obtain a velocity estimate;
• means for integrating the velocity estimate to determine an integrated velocity estimate;
• means for subtracting a GPS position from the integrated velocity estimate to determine a position noise error;
• means for filtering the position noise error;
• and
• means for adding the filtered position noise error to the integrated velocity estimate to obtain a position estimate.

A position determining device for determining a position of an object, the device comprising:

• a first filter circuit including,
• a first integrator adapted to integrate an acceleration estimate to determine an integrated acceleration,
• a first subtractor adapted to subtract a GPS velocity from the determined integrated acceleration estimate to determine a velocity noise error,
• a first low pass filter adapted to filter the velocity noise error,
• a first adder adapted to add the filtered velocity noise error to the integrated acceleration estimate to determine a velocity estimate;
• and
• a second filter circuit including,
• a second integrator adapted to integrate the velocity estimate to determine an integrated velocity estimate,
• a second subtractor adapted to subtract a GPS position from the determined integrated velocity estimate to determine a position noise error,
• a second low pass filter adapted to filter the position noise error, and
• a second adder adapted to add the filtered position noise error to the integrated velocity estimate to determine a position estimate.