Laser altimeters are capable of achieving fine mapping of the permanently shadowed regions (PSRs) of the Moon, which can provide fundamental topographic data for planetary missions. However, various factors can cause uncertainty in the geolocation of laser spots, which in turn causes terrain artifacts. In this article, we present an iterative self-constrained adjustment method to reduce the uncertainty of laser spot positioning. First, grid search was conducted for each altimetric profile from the lunar orbiter laser altimeter (LOLA), to minimize the weighted root-mean-square error (RMSE), constrained by the other altimetric profiles. Second, the updated profiles were iteratively adjusted until the adjustment value for the plane position converged. In addition, statistics from the standardized de-trended slope and residual were created to eliminate outliers, which were indeed some pseudo-topographic observations. In order to validate the results, the deviation of the elevation by projecting the adjusted laser profiles onto the improved LOLA digital elevation model (DEM) were calculated. The mean absolute error between the two is 0.25 m and the RMSE is 0.46 m. For the local terrain features with large differences, high resolution optical images were used for visual interpretation. The analysis shows that the obtained results appear to be more reasonable. Finally, using the corrected LOLA altimetric data, we made a new DEM of the PSRs within 89 & DEG;S of the lunar south pole, which can provide a refined and reliable topographic dataset for follow-up research.

Potential water ice concentrated within the permanently shadowed regions (PSRs) near lunar poles is both scientifically significant and of value for future explorations. However, after decades of observations, the existence and characteristics of PSR water ice remain controversial. The 1,064-nm laser reflectance measurements collected by the Lunar Orbiter Laser Altimeter (LOLA) onboard the Lunar Reconnaissance Orbiter (LRO) provide a unique opportunity to detect and characterize PSR water ice. In this work, we focus on all major PSRs on the flat floors of lunar polar craters and analyze their detailed LOLA 1,064-nm albedo and then compare this with the adjacent flat non-PSRs. We find that the LOLA albedo of the majority of these PSRs is systematically higher than their adjacent non-PSRs. Potential contributions of various factors to the observed LOLA albedo are individually quantitatively evaluated; we show that each of them is unable to account for the observed LOLA albedo anomalies and that the presence of surface water ice is the most likely explanation. Combined characterization of LOLA albedo and substrate impact cratering records (crater populations and depths) reveals that the inferred PSR water ices are in very small quantity (probably in the form of a surface frost layer or admixture with regolith) and are laterally heterogeneous in model ice concentration, ranging from negligible to similar to 6%. We recommend that these PSRs as priority targets for future surface in situ exploration endeavors, and a case assessment of Amundsen crater is presented.

Next Indian Lunar mission Chandrayaan-2 is expected to be launched in 2017/18 with a Lunar Orbiter Lander and Rover. Basically, the requirement of the Lander includes communication, Landing area shape, topography and sunlit area. For analyzing the landing site of chandryaan-2 we are using the data of LOLA which is one of the payloads onboard Lunar Reconnaissance Orbiter (LRO). The Lunar Orbiter Laser Altimeter (LOLA) is an instrument designed to assist in the selection of landing sites on the Moon for future robotic and human exploration. ICRS has analyzed total ten craters; three of them are located in the North Pole while remaining seven craters are located in the South Pole of the Moon. Permanently Shadowed Region (PSR) on the south pole of the lunar surface is of special interest to researchers due the presence of trapped water ice into these PSRs.