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Search Publications by: Neil Ashby (Assoc)

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Displaying 76 - 100 of 102

Relativity and Timing in X-ray Pulsar Navigation

June 5, 2006
Author(s)
Neil Ashby, David A. Howe
XNAV is a technology demonstration that will use photons from X-ray pulsars for navigation and spacecraft attitude determination. This paper summarizes relativistic effects in the context of XNAV. It also characterizes the primary task in the time domain

PARCS: NASAs Laser-Cooled Atomic clock in Space

December 1, 2005
Author(s)
Donald Sullivan, Neil Ashby, Elizabeth A. Donley, Thomas P. Heavner, Leo W. Hollberg, Steven R. Jefferts, William Klipstein, David Seidel, D. J. Phillips
The PARCS (Primary Atomic Reference Clock in Space) mission is designed, not only to perform certain tests of relativity theory, but also to demonstrate space-clock technology that may prove useful as an international standard of frequency and time and for

On the Power Dependence of Extraneous Microwave Fields in Atomic Frequency Standards

August 29, 2005
Author(s)
Steven R. Jefferts, Jon H. Shirley, Neil Ashby, Thomas P. Heavner, Elizabeth A. Donley, F Levi
We show that the frequency bias caused by distributed cavity phase has a strong dependence on microwave power. We also show that frequency biases associated with microwave leakage have distinct signatures in their dependence on microwave power and the

Frequency Biases Associated with Distributed Cavity Phase and Microwave Leakage in the Atomic Fountian Primary Frequency Standards IEN-CSF1 and NIST-F1

March 21, 2005
Author(s)
Steven R. Jefferts, Jon H. Shirley, Neil Ashby, Thomas P. Heavner, Elizabeth A. Donley, F Levi, Eric A. Burt, G J. Dick
The subject of frequency shifts in atomic frequency standards caused either by distributed cavity phase or microwave leakage goes back to the earliest days of the thermal beam standards [1,2], and has been the subject of continuing theoretical and

A U.S. Laser-Cooled Atomic-Clock System for Space

January 1, 2001
Author(s)
Donald Sullivan, Thomas P. Heavner, Leo W. Hollberg, D Meekhof, Thomas E. Parker, William D. Phillips, S L. Rolston, Hugh Robinson, Jon H. Shirley, F L. Walls, Neil Ashby, W Kepstein, L Maleki, D Seidel, R Q. Thompson, S Wu, L Young, R Vessot, E Mattison, A Demarchi

PARCS: A Laser-Cooled Atomic Clock in Space

January 1, 2001
Author(s)
Thomas P. Heavner, Leo W. Hollberg, Steven R. Jefferts, Hugh Robinson, Donald Sullivan, F L. Walls, Neil Ashby, W Klipstein, L Maleki, D Seidel, R Q. Thompson, L Young, E Mattison, R Vessot, A Demarchi

PARCS - A Primary Atomic Reference Clock in Space

January 1, 2000
Author(s)
Thomas P. Heavner, Leo W. Hollberg, Steven R. Jefferts, D Meekhof, Thomas E. Parker, William D. Phillips, S L. Rolston, Neil Ashby, W Klipstein, L Maleki, D Seidel, R W. Thompson, L Young, R Vessot, E Mattison, A Demarchi

Progress on PARCS

January 1, 2000
Author(s)
Thomas P. Heavner, Leo W. Hollberg, Steven R. Jefferts, D Meekhof, Thomas E. Parker, William D. Phillips, S L. Rolston, Hugh Robinson, Donald Sullivan, F L. Walls, Neil Ashby, W Klipstein, L Maleki, D Seidel, R Q. Thompson, S Wu, L Young, R Vessot, E Mattison, A Demarchi