Presentation Information
[PPS02-P06]Error assessment of 250-m resolution Lunar Gravitational Maps 2026
*Blazej Bucha1 (1.Slovak University of Technology in Bratislava, Department of Theoretical Geodesy and Geoinformatics)
Keywords:
Moon,Gravitational field,Satellite gravity,Topography,3D variable density,Gravity-forward modeling
Lunar Gravitational Maps 2026 (LGM2026) are novel yet-to-be-released maps of the gravitational potential, vector and tensor sampled at the 250-m resolution at the lunar surface and on its circumscribing sphere. The maps combine gravity observed by the GRAIL satellites (long wavelengths up to 11 km at the equator) with gravity inferred from the LRO and Kaguya topography employing 3D crustal density (short wavelengths up to 250 m). As a by-product, LGM2026 was converted into an external solid spherical harmonic expansion up to degree 11,519. This contribution focuses on the error assessment of LGM2026. First, we estimate commission errors for each LGM2026 quantity. To this end, we (i) propagate errors of the GRAIL-based spherical-harmonic gravitational model onto the lunar surface and its circumscribing sphere, (ii) study the propagation of errors of the topographic and density models to LGM2026 quantities and (iii) assess accuracy of gravity-forward modeling techniques that were used to deliver the key short-scale component of LGM2026. Second, we conduct an evaluation of LGM2026 with respect to (i) satellite gravity from GRAIL, (ii) surface gravity determined during the Apollo missions and (iii) gravity modeled from LGM2011, the most detailed model of the lunar surface gravitational field to date. Our error analysis suggests the 2-mGal accuracy of LGM2026 in terms of the gravitational vector at the lunar surface. LGM2026 will be released in mid-2026. This work was funded by the EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the project No. 09I03-03-V04-00273.