Abstract: A navigation system that provides a position estimate. In one embodiment, a method includes integrating an acceleration estimate in each of three dimensions. Subtracting a GPS velocity in each of the dimensions from the integrated acceleration estimate in each dimension 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.

Abstract: A navigation system comprises a global positioning satellite receiver to receive at least one global positioning satellite signal and to output global positioning satellite information. The navigation system further comprises a programmable processor, communicatively coupled to the global positioning satellite receiver, to execute software. The navigation system further comprises a clock, communicatively to the programmable processor, to output processor clock information. The software estimates an amount of drift in the processor clock information using the GPS information and adjusts the processor clock information for the amount of drift in order to generate adjusted processor clock information. The software generates a navigation solution as a function of at least the global positioning satellite information and the adjusted processor clock information.