TY - JOUR

T1 - Advantages of combining Lunar Laser Ranging and Differential Lunar Laser Ranging

AU - Zhang, Mingyue

AU - Müller, Jürgen

AU - Biskupek, Liliane

N1 - Current LLR data were collected, archived, and distributed under the auspices of the International Laser Ranging Service (ILRS; Pearlman et al. 2019). We acknowledge with thanks that since 1969 LLR data has been obtained under the efforts of the personnel at the McDonald Observatory in Texas, USA, the LURE Observatory in Maui, Hawaii, USA, the Observatoire de la Côte d’Azur in France, the Wettzell Laser Ranging System in Germany, the Matera Laser Ranging station in Italy and the Apache Point Observatory in New Mexico, USA. The authors would like to acknowledge the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy-EXC-2123 QuantumFrontiers – Project-ID 390837967 and the SFB 1464 TerraQ – Project-ID 434617780.

PY - 2024/1

Y1 - 2024/1

N2 - Context. Differential Lunar Laser Ranging (DLLR), which is planned to be conducted at Table Mountain Observatory (TMO) of Jet Propulsion Laboratory (JPL) in the future, is a novel technique for tracking to the Moon. This technique has the potential to determine the orientation, rotation, and interior of the Moon much more accurately if the expected high accuracy of about 30 μm can be achieved. Aims. We focus on the benefit for the related parameters when only DLLR data with a short time span are available in the beginning. Methods. A short DLLR time series is not enough to provide an accurate lunar orbit, which has a negative effect on parameter estimation. Fortunately, Lunar Laser Ranging (LLR) has been collecting data for a very long time span, which can be used to compensate this DLLR disadvantage. The combination of LLR data (over more than 50 yr) and simulated DLLR data over a relatively short time span (e.g., 5 or 10 yr) is used in different cases which include changing reflector baselines and extending data time span, along with adding more stations and new reflectors. Results. The results show that the estimated accuracies of the parameters related to the lunar orientation, rotation, and interior can be improved by about 5 100 times by simply adding 5-yr DLLR data in the combination. With LLR, further enhancing the parameter determination can be achieved by choosing appropriate reflector baselines. By investigating different scenarios of reflector baselines based on the present five reflectors on the Moon, we find that two crossing baselines with larger lengths offer the greatest advantage. A longer data time span is more helpful, rather than having more stations involved in the measurement within a shorter time span, assuming the amount of data in these two cases is the same. Furthermore, we evaluated the preferred position of an assumed new reflector.

AB - Context. Differential Lunar Laser Ranging (DLLR), which is planned to be conducted at Table Mountain Observatory (TMO) of Jet Propulsion Laboratory (JPL) in the future, is a novel technique for tracking to the Moon. This technique has the potential to determine the orientation, rotation, and interior of the Moon much more accurately if the expected high accuracy of about 30 μm can be achieved. Aims. We focus on the benefit for the related parameters when only DLLR data with a short time span are available in the beginning. Methods. A short DLLR time series is not enough to provide an accurate lunar orbit, which has a negative effect on parameter estimation. Fortunately, Lunar Laser Ranging (LLR) has been collecting data for a very long time span, which can be used to compensate this DLLR disadvantage. The combination of LLR data (over more than 50 yr) and simulated DLLR data over a relatively short time span (e.g., 5 or 10 yr) is used in different cases which include changing reflector baselines and extending data time span, along with adding more stations and new reflectors. Results. The results show that the estimated accuracies of the parameters related to the lunar orientation, rotation, and interior can be improved by about 5 100 times by simply adding 5-yr DLLR data in the combination. With LLR, further enhancing the parameter determination can be achieved by choosing appropriate reflector baselines. By investigating different scenarios of reflector baselines based on the present five reflectors on the Moon, we find that two crossing baselines with larger lengths offer the greatest advantage. A longer data time span is more helpful, rather than having more stations involved in the measurement within a shorter time span, assuming the amount of data in these two cases is the same. Furthermore, we evaluated the preferred position of an assumed new reflector.

KW - Astrometry

KW - Celestial mechanics

KW - Methods: data analysis

KW - Moon

UR - http://www.scopus.com/inward/record.url?scp=85180965059&partnerID=8YFLogxK

U2 - 10.1051/0004-6361/202347643

DO - 10.1051/0004-6361/202347643

M3 - Article

VL - 681

JO - Astronomy & Astrophysics

JF - Astronomy & Astrophysics

M1 - A5

ER -