University:
Massachusetts Institute of Technology
Course:
12.540 | Principles of the Global Positioning System
Academic year:

2023
Views:

66

Pages:

7
Author:

Saige Burke

Principles of the Global Positioning System Summary • Sources of GPS data and results – Major international organizations involved in GPS – Examine access to GPS data – Examine access to GPS results 1 GPS Groups/IGS • There are many international and national groups involved in the deployment of GPS. • The international organization is the International GPS Service (IGS) • Started as pilot project by the International Association of Geodesy (IAG) in 1992. • Involves: – – – – Data collection (standards for stations) Data dissemination (through several archives) Data analysis (IGS analysis centers) Analysis improvements (working groups and standards) Current IGS Network (approximately 200 stations) 2 North American Portion of network European part of network 3 IGS • Data for each IGS station is openly available usually within <1 day of collection. Some sites are available hourly. • Explore site for structure: Web site index gives an overview of page content. US Groups • There are a number of large US groups that run GPS networks. • Largest array is the Southern California Integrated array (SCIGN) with 250 stations • Other groups in the Western United States have networks of 20-50 stations. In all over 400 geophysical class stations in Western US. 4 National Geodetic Survey CORS • Main reference frame of the United States. • Continuously Operating Reference Stations (CORS) • Serves the geodetic control needs of the US. • About 300 GPS sites currently in the network many of them shared with other institutions. 5 Availability of processed GPS data • Many of the network groups put analyzed results on their web pages as well as access to data. • IGS also sponsors 7 global analysis groups (funding comes from other sources). Other important groups • University Navstar Consortium (UNAVCO) facility and corporation • Supports a variety of applications of GPS. Initially tectonic deformation but now Antarctic Research and low-precision GIS applications • Supports US Universities in installing GPS through out the world for geophysical studies. 6 Summary • Data from thousands of GPS stations are collected and processed each data • Largest single array is in Japan (>1000 stations) • GPS developments are like the internet development: Many active contributors but often quality is debatable. 7