Using LROC WAC data for Lunar surface photoclinometry

All available lunar digital elevation models, e.g., SELENE LALT DEM, SELENE DTM LISM, Chang’E-1 LAM DEM, GLD100, SLDEM2015, have certain disadvantages, including insufficient resolution and/or the presence of defects as well as mismatching reference coordinate systems, making it difficult to incorporate the topographic effect on photometric LROC WAC observations. We here propose a photoclinometry technique that can be used to account for this effect. To do so, we modify our algorithm used to construct seamless photometric mosaics (Korokhin et al., PSS 2016, 122, 70–87) to determine local slopes simultaneously with parameters of photometric function during the mosaicing procedure. This technique can be useful for improvement of quality of remote sensing of surfaces with complex topography. We also develop a new algorithm for constructing the lunar digital elevation model based on the simultaneous use of laser altimetric measurements (LRO LOLA) and local longitudinal slopes obtained photoclinometrically from LROC WAC data. The algorithm provides a digital elevation model with accuracy and resolution not worse than SLDEM2015, yet demonstrating significantly fewer defects and artifacts. High-quality topo data can be useful for geology, geomorphology and for navigation/exploration/mission planning

The PHEMU15 catalogue and astrometric results of the Jupiter's Galilean satellite mutual occultation and eclipse observations made in 2014–2015

During the 2014-2015 mutual events season, the Institut de Mécanique Céleste et de Calcul desÉphémérides (IMCCE), Paris, France, and the Sternberg Astronomical Institute (SAI), Moscow, Russia, led an international observation campaign to record ground-based photomet-ric observations of Galilean moon mutual occultations and eclipses. We focused on processing the complete photometric observations data base to compute new accurate astrometric positions. We used our method to derive astrometric positions from the light curves of the events

The PHEMU15 catalogue and astrometric results of the Jupiter's Galilean satellite mutual occultation and eclipse observations made in 2014-2015

During the 2014-2015 mutual events season, the Institut de Mécanique Céleste et de Calcul des Éphémérides (IMCCE), Paris, France, and the Sternberg Astronomical Institute (SAI), Moscow, Russia, led an international observation campaign to record ground-based photometric observations of Galilean moon mutual occultations and eclipses.We focused on processing the complete photometric observations data base to compute new accurate astrometric positions. We used our method to derive astrometric positions from the light curves of the events. We developed an accurate photometric model of mutual occultations and eclipses, while correcting for the satellite albedos, Hapke's light scattering law, the phase effect, and the limb darkening. We processed 609 light curves, and we compared the observed positions of the satellites with the theoretical positions from IMCCE NOE-5-2010-GAL satellite ephemerides and INPOP13c planetary ephemeris. The standard deviation after fitting the light curve in equatorial positions is ±24 mas, or 75 km at Jupiter. The rms (O-C) in equatorial positions is ±50 mas, or 150 km at Jupiter. © 2017 The Author(s)