ASSESSMENT OF CONTINOUSLY OPERATING REFERENCE STATIONS (CORS) IN SOUTH WEST NIGERIA

Abstract

The Federal Government of Nigeria through the Office of the Surveyor General of the Federation (OSGOF) has set up a surveying infrastructure throughout the country known as the Continuously Operating Reference Stations (CORS); to replace the traditional geodeticpassive networks which are the basic infrastructure for Surveying and Mapping in anycountry. Using the United States of America’s CORS map stations as a standard, having in mind the National Geodetic Survey’s (NGS) guiding principle for establishing new CORS which states that “proposed CORS will be no closer than 70km from an existing CORS”, hence, the spatial coverage of theNigerian GNSSreference network (NIGNET) on a distance of more than 300km in between the stationsseems insufficient based on the globalstation densification standard of the International Terrestrial Reference Frame (ITRF) adopted by the Global Geodetic Reference Frame (GGRF). The aim of this study is to develop a suitability map for CORS network in South West Nigeria with a view of assessing the level of compliance of the existing CORS network towards improving the density of the CORS network thereby extending the spatial coverage with a robust network. The data used for this study were secondary data and from different sources. The study was carried out in GIS environment using weight and overlay method with AHP technique. Result from the suitability revealed that, about 70% of the study area is suitable for the establishment of new CORS network. Therefore, the information derived through this study will be of help to policy makers for effective decision making and sustainable development