Test of simulated pseudolite measurements applied to GPS and multi-pseudolite integrated positioning

The near-ground operation of a GPS-like signal transmitter, the pseudolite (PL), is expected to provide extra-measurements and improve the GPS positioning accuracy and availability. Based on the true measurements received from one PL instrument during the field trial, the multi-session combined technique and the self-session duplicated technique were proposed and tested for PL data simulation. The results demonstrate that the self-session duplicated technique can effectively provide the simulated PL measurements for any appropriate number and adequate configuration of so-called virtual PL (VPL) sites. The GPS+PL+3VPL observations were practically integrated to compute for a baseline solution. The results prove that baseline precision can be significantly improved by approximately 50% and 30% on the horizontal and vertical components, respectively, compared with those using only GPS data. When VPL sites are simulated to have the minus elevation angles, the vertical positioning errors can be further reduced to achieve a consistent precision in all three-dimensional coordinates. This preliminary study has shown good performance of using simulated PL measurements for integrated GPS and multi-pseudolite positioning.