Related papers: Lunar Reference Timescale
A radio telescope placed in lunar orbit, or on the surface of the Moon's farside, could be of great value to the Search for Extraterrestrial Intelligence (SETI). The advantage of such a telescope is that it would be shielded by the body of…
This paper shows how the exposure of the Moon to the Earth's plasmasheet is subject to decadal variations due to lunar precession. The latter is a key property of the Moon's apparent orbit around the Earth - the nodes of that orbit precess…
For relativistic modelling of high-accuracy astronomical data several time scales are used: barycentric and geocentric coordinate times, TCB and TCG, as well as two additional time scales, TDB and TT, that are defined as linear functions of…
This paper provides an overview of the Lunar Laser Ranging (LLR) experiments. The measurement principle is explained and its theory is derived. Both contributions, the direct reflected light from retroreflectors as well as the scattered…
The perturbation of the lunar motion caused by a hypothetical violation of the equivalence principle is analytically worked out in terms of power series \`a la Hill-Brown. The interaction with the quadrupolar tide is found to amplify the…
Possible explanations of the recently reported anomalous increase of the eccentricity of the lunar orbit are sought in terms of classical Newtonian mechanics, general relativity, and long-range modifications of gravity.
The conflict between quantum theory and the theory of relativity is exemplified in their treatment of time. We examine the ways in which their conceptions differ, and describe a semiclassical clock model combining elements of both theories.…
We present analog clocks fitted to the Mars solar day. These clocks use the standard Earth-based second of the International System of Units (SI) as their operational unit of time, unlike current practice for Mars timekeeping. We discuss…
Onboard localization capabilities for planetary rovers to date have used relative navigation, by integrating combinations of wheel odometry, visual odometry, and inertial measurements during each drive to track position relative to the…
This paper discusses how to build a time scale with an intermittently-operated optical clock. In particular, it gives suggestions on how long and how often to run an optical clock. It also explores the benefits of having an optical clock in…
All future lunar missions require a definition of the lunar reference system and a realization in the form of the lunar reference frame to ensure consistent products for positioning, navigation, cartography, and timing. This paper defines…
Existing capabilities in laser ranging, optical interferometry and metrology, in combination with precision frequency standards, atom-based quantum sensors, and drag-free technologies, are critical for the space-based tests of fundamental…
Given the renewed scientific interest in lunar exploration missions, complete understanding of lunar near surface environment and its exosphere under different conditions is of paramount importance. Lunar exosphere has been extensively…
Although the effects of solar (and lunar) gravitational potentials on the frequencies of orbiting Global Positioning System (GPS) clocks are actually no more than a few parts in 10^(15), a na\"ive calculation appears to show that such…
Reference systems and frames are crucial for high precision absolute astrometric work, and their foundations must be well-defined. The current frame, the International Celestial Reference Frame, will be discussed: its history, the use of…
The main theoretical aspects of gravitomagnetism are reviewed. It is shown that the gravitomagnetic precession of a gyroscope is intimately connected with the special temporal structure around a rotating mass that is revealed by the…
Analytical treatment of time transfer problem for Earth-Satellite system is presented. The development was made in a complete relativistic framework. In accordance with modern clock precision and for low altitude orbits, we neglect the…
The passive retroreflector arrays placed on the moon by Apollo 11, 14 and 15 astronauts continue to produce valuable Earth-Moon range measurements that enable high-precision tests of gravitational physics, as well as studies of geo- and…
The general relativistic gravitomagnetic clock effect, in its simplest form, consists of the non-vanishing difference in the orbital periods of two counter-orbiting objects moving in opposite directions along circular orbits lying in the…
A careful study is made of the operational meaning of the time symbols appearing in the space-time Lorentz transformation. Four distinct symbols, with different physical meanings, are needed to describe reciprocal measurements involving…