Abstract: | A status report is presented for a time transfer experiment which compares the times of flight in the east-west and west-east directions of short pulses of light sent from a laser coupled to the 48-inch telescope at the NASA Goddard Optical Research Facility to the U.S. Naval Observatory and reflected back over the same path. The times t, and t, when each light pulse leaves GORF and returns are measured with an event timer referenced to a hydrogen maser. The time t, when the pulse is reflected at USNO is measured with a portable event timer and maser combination carried in a heated and air-conditioned truck. Each maser is maintained in a temperature-controlled environment. The portable maser enclosure is supported by pneumatic shock and vibration suppression mounts. The quantity ar = t,- (t, + y = { ret, -t, - (t, - tyi is determined. The apparatus is calibrated by performing corresponding measurements with the portable detector at GORF in the same equipment configuration used at USNO while also monitoring the phase difference between the masers. The central question to be answered by the experiment is whether the Einstein prescription for the synchronization of clocks with light pulses occurs automatically (AT = 0) or must be imposed by convention in the context of a theory (AT + 0). The necessary precision of s 50 ps has not yet been achieved for the complete measurement although it has been accomplished for clock trips and laser pulse detection on separate occasions. |
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Proceedings of the 20th Annual Precise Time and Time Interval Systems and Applications Meeting November 29 - 1, 1988 Sheraton Premiere Hotel Vienna, Virginia |
Pages: | 261 - 286 |
Cite this article: | Alley, C.O., Nelson, R.A., Shih, Y.H., Agnew, B.W., Bartolo, R.E., Broomfield, J.T., Fogleman, J.A., Hunt, J.C., Li, M.G., Perry, M.A., Rayner, J.D., Steggerda, C.A., Wang, B.C., Chandler, M.J., Rueger, L.J., Wilcox, J.L., "DIFFERENTIAL COMPARISON OF THE ONE-WAY SPEED OF LIGHT IN THE EAST-WEST AND WEST-EAST DIRECTIONS ON THE ROTATING EARTH," Proceedings of the 20th Annual Precise Time and Time Interval Systems and Applications Meeting, Vienna, Virginia, November 1988, pp. 261-286. |
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