Survey of Capabilities and Applications of Accurate Clocks: Directions for Planetary Science

Déhant, V.; Park, Ryan; Dirkx, D.; Iess, L.; Neumann, Gregory A.; Turyshev, Slava G.; Hoolst, Tim Van

doi:10.1007/s11214-017-0424-y

Cited by 9 publications

(12 citation statements)

References 45 publications

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“…To highlight the differences between DLLR and LLR, a summary of their specific features is shown in Table 1. The information on DLLR in Table 1 is taken from Dehant et al (2017).…”

Section: Comparison Of the Llr And Dllr Conceptsmentioning

confidence: 99%

“…Less than or equal to one photon per laser pulse is received by most of the LLR stations (Murphy 2013;Chapront & Francou 2006). Only the APOLLO station can conduct multi-photon detection, getting 3-5 photons per pulse (Dehant et al 2017;Murphy et al 2008).…”

Section: Signal Intensitymentioning

confidence: 99%

“…With the improvements of the LLR stations, the main error sources of the LLR measurements are the reflectors on the Moon (Williams et al 2009), the LLR model (Williams et al 2004) and the Earth's atmosphere (which is the primary one). The atmosphere imposes a lower limit of 5 mm for the current LLR operations (Dehant et al 2017).…”

Section: Introductionmentioning

confidence: 99%

“…Equipped with a 1-meter telescope and a high-power continuous wave (CW) laser (operating at 1064 nm and amplitudemodulated with a linear chirp), a novel LLR station at Table Mountain Observatory (Dehant et al 2017) of JPL will enable a new type of a geodesy technique known as Differential Lunar Laser Ranging (DLLR). A DLLR station can switch between two or more reflectors within a short time interval (nearly simultaneously).…”

Section: Introductionmentioning

confidence: 99%

“…Due to the substantial decrease of the atmospheric error and the accurate DLLR data, it is anticipated that DLLR will provide a dramatic enhancement of our understanding of the deep lunar interior. This relates to, for instance, the boundary of the lunar core and mantle, the rotation of the core and the dissipation of a suspected partial melting area, and so on (Turyshev et al 2018;Dehant et al 2017). In addition, Turyshev et al (2018) mentioned that DLLR can also be beneficial for some relativity tests, for example, related to the temporal variation of the gravitational constant G and the EP.…”

Section: Introductionmentioning

confidence: 99%

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Characteristics of differential lunar laser ranging

Zhang

Müller

Biskupek

et al. 2022

A&A

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Context. To obtain more details about the lunar interior, a station at Table Mountain Observatory of JPL will enable a new measurement of lunar laser ranging (LLR), known as differential lunar laser ranging (DLLR). It will provide a novel type of observable, namely, the lunar range difference, which is the difference of two consecutive ranges obtained via a single station swiftly switching between two or more lunar reflectors. This previously unavailable observation will have a very high level of accuracy (about 30 µm), mainly resulting from a reduction in the Earth's atmospheric error. In addition to the intended improvements for the lunar part, it is expected to contribute to improved relativity tests, for instance, the equivalence principle (EP). Aims. This paper focuses on the simulation and investigation of the characteristics of DLLR. Methods. Using simulated DLLR data, we analyzed and compared the parameter sensitivity, correlation, and accuracy obtained by DLLR with those attained by LLR. Results. The DLLR measurement maintains almost the same sensitivity to certain parameters (called group A) as that of LLR, such as the lunar orientation parameters. For other parameters (called group B), such as station coordinates, it is shown to be less sensitive. However, owing to its extraordinary measurement accuracy, it not only retains nearly the same level of accuracy of group B as LLR, but it also improves the estimation of group A significantly (with the exception of reflector coordinates, due to the DLLR measuring mode). Also, DLLR increases the correlations among the reflectors and between stations and reflectors caused by its constellation. Additionally, we compared different switching intervals with respect to sensitivity and correlation. Large switching intervals are more beneficial for group B and the decorrelation of stations and reflectors. Furthermore, DLLR enhances the accuracy of EP tests.

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“…To highlight the differences between DLLR and LLR, a summary of their specific features is shown in Table 1. The information on DLLR in Table 1 is taken from Dehant et al (2017).…”

Section: Comparison Of the Llr And Dllr Conceptsmentioning

confidence: 99%

Section: Signal Intensitymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Characteristics of differential lunar laser ranging

Zhang

Müller

Biskupek

et al. 2022

A&A

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Laser and radio tracking for planetary science missions—a comparison

Dirkx

Procházka

Bauer

et al. 2018

J Geod

Self Cite

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At present, tracking data for planetary missions largely consists of radio observables: range-rate (Doppler), range and angular position (VLBI/ DOR). Future planetary missions may use Interplanetary Laser Ranging (ILR) as a tracking observable. Two-way ILR will provide range data that are about 2 orders of magnitude more accurate than radio-based range data. ILR does not produce Doppler data, however. In this article, we compare the relative strength of radio Doppler and laser range data for the retrieval of parameters of interest in planetary missions, to clarify and quantify the science case of ILR, with a focus on geodetic observables. We first provide an overview of the near-term attainable quality of ILR, in terms of both the realization of the observable and the models used to process the measurements. Subsequently, we analyse the sensitivity of radio Doppler and laser range measurements in representative mission scenarios for parameters of interest. We use both an analytical approximation and numerical analyses of the relative sensitivity of ILR and radio Doppler observables for more general cases. We show that mm-precise range normal points are feasible for ILR, but mm-level accuracy and stability in the full analysis chain are unlikely to be attained, due to a combination of instrumental and model errors. We find that ILR has the potential for superior performance in observing signatures in the data with a characteristic period of greater than 0.33-1.65 hours (assuming 2-10 mm uncertainty for range and 10 µm/s at 60 s for Doppler). This indicates that Doppler tracking will typically remain the method of choice for gravity field determination and spacecraft orbit determination in planetary missions. ILR data will be able to supplement the orbiter tracking data used for the estimation of parameters with a once-per-orbit signal. Laser ranging data, however, are shown to have a significant advantage for the retrieval of rotational and tidal characteristics from landers. Similarly, laser ranging data will be superior for the construction of planetary ephemerides and the improvement of solar system tests of gravitation, both for orbiter and for lander missions.

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