An Introduction to a Rotating Table for High-Rate GPS Testing Abstract

abstract

  • High-rate GPS has been recognized as a new seismometer. Accuracy is the first concern in developing the new seismometer. Most studies about the accuracy of GPS were based on static or very slow movements of GPS antennas. However, very large antenna velocities would be anticipated during strong earthquakes if GPS is used as a seismometer in field. To our knowledge, there are only a few 1-Hz GPS recordings from natural earthquakes. It is very necessary to develop lab equipment to study the accuracy of the high-rate (e.g., 10-Hz, 50-Hz) kinematic GPS. We designed a very simple rotating table to compare the performance of high-rate GPS during faster and slow movements. The table was made with the back wheel of a bicycle. Two GPS antennas were mounted on the wheel. We performed a set of tests on the roof of the Physics Building at the University of Puerto Rico at Mayaguez. A reference GPS was installed about 15 meters away of the rotation table. Topcon GB-1000 GPS receiver and PG-AI w/GP Geodesic Antennas were used for both rover and reference stations. Our tests focus on evaluating the effects of rotation speed on the accuracy of high-rate kinematic GPS. A commercial GPS software Topcon Tools (Version 7.1) developed by the Topcon Inc. (http://global.topcon.com) was applied in calculating the kinematic positions. Our results show that the errors at a fast-rotation speed are larger than those at a slow-rotation speed.

authors

publication date

  • 2010

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