THE GRAVITOMAGNETIC FIELD AND ITS MEASUREMENT WITH THE LAGEOS SATELLITES

This paper is structured in four sections. In the first one we briefly describe the gravitomagnetic field and the Lense-Thirring effect in general relativity. In the second and third sections we review the method proposed to measure the Lense-Thirring effect by analyzing the orbits of the two laser-ranged satellites LAGEOS and LAGEOS II. We then report on our measurement of the Lense-Thirring effect by analyzing the data of LAGEOS and LAGEOS II with the orbital programs GEODYN-SOLVE, using the Earth's Gravitational Models JGM-3 and EGM-96, and the method explained in section 2. The first detection was obtained in 1995, the most accurate measurements were obtained in 1998 using EGM-96. Finally, in the fourth section, we briefly describe the proposed LARES experiment to measure the Lense-Thirring effect with accuracy of about 2%–3%.