Evaluation of the trade-off between Global Positioning System (GPS) accuracy and power saving from reduction of number of GPS receiver channels

Abstract

This study is aimed at evaluating the trade-off between Global Positioning System (GPS) accuracy and power saving from reduction of number of channels. The study is conducted for number of GPS receiver channels of 4 to 12 for two scenarios: (1) normal scenario with full range of available GPS satellites and (2) obstruction scenario with GPS satellite elevation cutoff of 20°. It is observed that increase of power saving from reducing the number of channels causes increase of probable error values. This is due to increasing position dilution of precision (PDOP) of the reducing number of GPS satellites tracked. However, reduction of number of channels to match the number of available GPS satellites does not cause degradation of accuracy, as there is no reduction in number of trackable GPS satellites. For the obstruction scenario, with significantly fewer available GPS satellites due to the GPS satellite elevation cutoff, significant power saving can be achieved without degradation of accuracy. An effective power saving system would require the management of minimum number of channels required to achieve the user's minimum required accuracy.

Robust Positioning and Navigation of a Mobile Robot in an Urban Environment Using a Motion Estimator

“…Several factors cause errors in GPS positioning and navigation systems, including satellite orbit error, satellite time error, ionospheric group delay, tropospheric group delay, multipath, receiver errors, selective availability, and the geometrical formation of satellites. 27,28 To improve the positioning accuracy of the GPS receiver, these noise sources need to be cancelled out. For the cancellation or compensation of satellite signals, rigorous analysis of the satellite signal is required.…”