Lunar Reconnaissance Orbiter: Enabling CLPS Mission Success

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METHODS OF IMAGE RESTORATION FOR INCOHERENT AND COHERENT SYSTEMS (DECONVOLUTION, SIGNAL RECOVERY, DEBLURRING, ENHANCEMENT)

Satellite-based multispectral imaging systems have been in operation since 1972. The latest in the Landsat series of sensors was launched in March 1984. One of the system parameters of interest is resolution and in this thesis results in estimating the actual overall resolution after launch are discussed. Scene structures such as field edges are used with numerical estimation procedures to predict resolution. A discriminant function, based on statistical methods, is developed for the selection or rejection of the scene elements to be used. Different approaches are considered for processing the data used in the estimate of the LSF. For estimating the 2-dimensional PSF a parametric model using a finite number of edges in different orientations is presented. Knowing the PSF a restoration method is developed which, if desired, could be easily incorporated into the existing software used for processing the Landsat imagery. The restoration algorithm is a generalization of the method of compensating the Composite Point Spread Function (CPSF) using FIR filters, with the addition of direct constraints over the side-lobe levels present in the CPSF. Depending on the PSF and sampling rate, excellent results were obtained in controlling the side-lobe levels. In some cases they are reduced below the quantization level of the system, making them unnoticeable. An extension of the restoration method to coherent image formation systems is discussed. Results in enhancing TM Landsat data are presented

The Distribution of Molecular Water in the Lunar South Polar Region Based upon 6 μm Spectroscopic Imaging

The amount and distribution of water on the lunar surface are related to the input and production of water by solar wind and meteoroid bombardment, balanced by photodestruction and mobility across the surface. Using the Stratospheric Observatory for Infrared Astronomy (SOFIA), we imaged the 6.1 μ m feature that uniquely traces molecular water, covering 1/4 of the lunar nearside surface south of −60° latitude with 5 km resolution on 2022 February 17 UTC. The water feature strength varies significantly across the region, being drier at +28° longitude to more wet (170 ppm) at −7° longitude, and also decreasing toward the pole. Significant local enhancements are found, associated with south-facing, high-altitude topographic features. This includes relatively high H _2 O concentrations in a “wet ridge” just north of the Curtius crater; the south-facing, northern, inner rims of the most prominent craters; the south face of the central peak of the Moretus crater; and permanently shadowed polar regions

THE ALASKA SAR DEMONSTRATION: RADARSAT-1 EXPERIENCE AND ENVISAT PLANS

Information Service (NESDIS) ENVISAT project is focused on a pre-operational demonstration of wind and vessel position products using, predominately, the Wide-Swath Mode of the ENVISAT Advanced Synthetic Aperture Radar (ASAR). The necessary scientific algorithms, data management techniques, and product production and dissemination procedures are being prototyped using Canadian RADARSAT-1 SAR data. A near real-time demonstration of SAR product production, the Alaska SAR Demonstration (AKDEMO) has been underway since October 1999 for the waters surrounding Alaska. Wind speed, wind vector (with 180 degree ambiguity) and vessel position products are generated within about 6 hours of satellite acquisition and provided to operational agencies for evaluation and validation. Wind validation is accomplished by comparing SAR-derived winds with model output in Alaska and with buoy measurements from the NOAA moored meteorological buoys in the Atlantic off the U.S. East Coast. For validation of vessel positions, fishery observer reports are being paired with SAR-derived positions to ascertain vessel detection success. ENVISAT data will first be taken over the U.S. East Coast buoys to test and validate the wind algorithm. The vessel detection algorithm will be tailored for the ENVISAT ASAR imagery and tested as well. Once the algorithms ar

The low-iron, reduced surface of Mercury as seen in spectral reflectance by MESSENGER

The MESSENGER spacecraft's Mercury Atmospheric and Surface Composition Spectrometer (MASCS) obtained more than 1.6 million reflectance spectra of Mercury's surface from near-ultraviolet to near-infrared wavelengths during the first year of orbital operations. A global analysis of spectra in the wavelength range 300-1450 nm shows little regional variation in absolute reflectance or spectral slopes and a lack of mineralogically diagnostic absorptions. In particular, reflectance spectra show no clear evidence for an absorption band centered near 1 μm that would be associated with the presence of ferrous iron in silicates. There is, however, evidence for an ultraviolet absorption possibly consistent with a very low iron content (2-3 wt% FeO or less) in surface silicates and for the presence of small amounts of metallic iron or other opaque minerals in the form of nano- or micrometer-sized particles. These findings are consistent with MESSENGER X-ray and gamma-ray measurements of Mercury's surface iron abundance. Although X-ray and gamma-ray observations indicate higher than expected quantities of sulfur on the surface, reflectance spectra show no absorption bands diagnostic of sulfide minerals. Whereas there is strong evidence of water ice in permanently shadowed craters near Mercury's poles, MASCS spectra provide no evidence for hydroxylated materials near permanently shadowed craters