Effective Use of A-GPS for Generating Geographical Coordinates to Locate Natural Gas Utilities in Suburban Area

The purpose of this study is to see that how geographical coordinates (Latitude & Longitude) generated using AGPS device can be useful in improving the geographical location of point utilities. This study has shown the use of AGPS for improving the location of utilities (EG: pipelines laid underground, different valves, service regulators, etc.) in GIS software at any gas distribution company. An Assisted GPS receiver is used to capture the point location and get the geographical coordinates of that location. A survey in this study shows the accuracy of this AGPS under different urban circumstances. To assess the accuracy of Assisted GPS, its results are compared with DGPS instrument which has an accuracy within few centimeters. The results obtained shows that 68 times out of 88 AGPS has given accuracy within 10 meters, maximum error being 35.82 meters. If we compare it with current system, out of 505 SRs 65 are shifted from their position with range of 15 meters to 160 meters and 85 SRs are missing from their place which can be of any range may be in kilometers. This error is far more than the results obtained from AGPS survey hence it can be effective to use AGPS. Though this technique cannot be used where accurate point positioning is required but this cheap and economical technique is useful where dislocation problem is in large scale.