01080512

Monograph

http://onlinepubs.trb.org...ail/hsr-52final_report.pdf

If the precise location of both train and track maintenance vehicles and equipment could be determined automatically at central dispatch, it could significantly improve the safety and efficiency of train movements through track maintenance areas. This could be achieved using an automatic precise location system on the train and on the maintenance vehicles that automatically transmits their respective locations to central dispatch. This Innovations Deserving Exploratory Analysis (IDEA) project focuses on the feasibility of automatically and precisely determining the location of maintenance vehicles and equipment using a Global Positioning System (GPS) Vehicle Location System (GVLS). GVLS uses a GPS receiver augmented with dead reckoning sensors, in order to provide the vehicle location when GPS coverage is interrupted. The GVLS achieves the required position accuracy by using a sophisticated carrier differential GPS (CDGPS) position algorithm. This algorithm compares the GPS carrier phase measurements from the GVLS receiver with GPS carrier phase measurements from a nearby reference receiver at a known (surveyed) location. Using these measurements, the algorithm estimates and removes line-of-sight slant range errors, such as the unknown carrier (integer) biases, and determines the relative position between the two receivers. The reference receiver measurements are obtained from a High Accuracy - National Differential GPS (HA-NDGPS) reference station network, which is currently under development as an upgrade to the existing NDGPS reference station network. Under this feasibility study, a candidate CDGPS algorithm was selected based on a review of the technical literature. This algorithm was coded in Matlab and tested with archived GPS data. The data were obtained from the Continuously Operating Reference Station (CORS) Network that is administered by the National Geodetic Survey, NOAA.

This HSR-IDEA project was conducted by Sensis Corporation, Seagull Technology Center, Campbell, CA. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved

HSR-IDEA Project 52

English

31p

2007-1

High-Speed Rail IDEA Program Project Final Report

Final Report

Print

Figures (25) ; Photos (1) ; References (28) ; Tables (14)

Accuracy; Algorithms; Automatic vehicle location; Dead reckoning; Global Positioning System; High speed rail; Maintenance of way; Positive train control; Technological innovations

Innovations Deserving Exploratory Analysis (IDEA) (Program)

Maintenance vehicles

Highways; Operations and Traffic Management; Railroads

TRIS, TRB

Oct 31 2007 2:04PM