In this paper, the performance of a digital beam steering antenna array, developed by NAVSYS Corporation, is presented for high accuracy differential and kinematic GPS applications. The NAVSYS’ High Gain Advanced GPS Receiver (HAGR). uses digital beam-steering to combine signals from an antenna array with up to sixteen elements and create a multi-beam antenna for up to eight GPS satellites simu...

This paper solves a replacement of inertial sensor mechanical calibration by calculation of the calibration constants using differential evolution algorithm. In the first section a simplified mathematicphysical model of inertial navigation is described. Then we describe the inertial sensor errors and its calibration. Main part of the paper deals with determination of accelerometers and gyroscop...

In this paper several detector schemes for processing weak GPS signals in an unaided acquisition scenario are described and analyzed. Fundamental theoretical considerations based on the generalized likelihood ratio test (GLRT), as applied to GPS signal detection, are discussed. It is shown that the asymptotic version of the GLRT is equivalent to an estimator correlator (EC). For assumed determi...

With the increasing demands of precise positioning in weak signal environment, high sensitive GNSS receiver research and development has been pushed badly in need. Conventional GNSS signal acquisition techniques are considered inadequate when the incoming signal is too weak. In this paper we have mainly consider wavelet denoising algorithm applying in weak GNSS signal acquisition. Conventional ...

Global Navigation Satellite (GPS) system has gradually come of age and has found itself a place as standard Navigation equipment in most aircraft. However, data from a GPS Receiver is not reliable enough for it to be used as a primary or sole source of navigation information. As a result GPS only system is allowed to be used only as a supplemental means of navigation for aircraft in the less cr...

Orbits for satellites o f the Global Positioning System (GPS) have been determined with submeter accuracy. Tests used to assess orbit accuracy include orbit comparisons from independent data sets, orbit prediction, ground baseline determination, and formal errors. One satellite tracked for 8 hours each day shows rms errors below I m even when predicted more than 3 days outside of a 1-week data ...

We present quad-constellation (namely, GPS, GLONASS, BeiDou and Galileo) time group delay (TGD) and differential code bias (DCB) correction models to fully exploit the code observations of all the four global navigation satellite systems (GNSSs) for navigation and positioning. The relationship between TGDs and DCBs for multi-GNSS is clearly figured out, and the equivalence of TGD and DCB correc...

Recent developments in differential GPS (DGPS) services have concentrated mainly on the reduction of the number of permanent reference stations required to cover a certain area and the extension of the possible ranges between reference and rover stations. Starting from networked DGPS stations where all stations are linked to a central control station for data correction and modeling, the most a...

Research into developing more reliable microscopic traffic simulation models is seriously hampered by the availability of suitable microscopic data for calibration and validation purposes. This paper presents a review of several data collection technologies that the authors have been experimenting with. The methods include (i) video recording (ii) the use of differential GPS (DGPS) and (iii) an...