No description available.

Remote Sensing Group (RSG) at the University of Arizona has a long history of using ground-based test sites for the calibration of airborne- and satellite-based sensors. Often, ground-truth measurements at these tests sites are not always successful due to weather and funding availability. Therefore, RSG has also employed automated ground instrument approaches and cross-calibration methods to verify the radiometric calibration of a sensor. The goal in the cross-calibration method is to transfer the calibration of a well-known sensor to that of a different sensor.This dissertation presents a method for determining the radiometric calibration of a hyperspectral imager using multispectral imagery. The work relies on a multispectral sensor, Moderate-resolution Imaging Spectroradiometer (MODIS), as a reference for the hyperspectral sensor Hyperion. Test sites used for comparisons are Railroad Valley in Nevada and a portion of the Libyan Desert in North Africa. A method to predict hyperspectral surface reflectance using a combination of MODIS data and spectral shape information is developed and applied for the characterization of Hyperion. Spectral shape information is based on RSG's historical in situ data for the Railroad Valley test site and spectral library data for the Libyan test site. Average atmospheric parameters, also based on historical measurements, are used in reflectance prediction and transfer to space. Results of several cross-calibration scenarios that differ in image acquisition coincidence, test site, and reference sensor are found for the characterization of Hyperion. These are compared with results from the reflectance-based approach of vicarious calibration, a well-documented method developed by the RSG that serves as a baseline for calibration performance for the cross-calibration method developed here. Cross-calibration provides results that are within 2% of those of reflectance-based results in most spectral regions. Larger disagreements exist for shorter wavelengths studied in this work as well as in spectral areas that experience absorption by the atmosphere.

An attitude control system for the BRITE and CanX-4&5 nanosatellites is developed. BRITE and CanX-4&5 are research satellites based on the Space Flight Laboratory’s Generic Nanosatellite Bus, devoted to the study of star brightness and formation flying, respectively. Novel low-cost testing procedures are developed and used to characterize satellite sensor and actuator performance. The algorithm governing the pointing of CanX-4&5 is enhanced based on preliminary simulation results. A linear-time invariant controller architecture, applicable to both BRITE and CanX-4&5, is designed based on simulation of several competing controllers. Testing information is combined with control laws and controller to simulate the attitude performance of the satellites throughout their missions.

An attitude control system for the BRITE and CanX-4&5 nanosatellites is developed. BRITE and CanX-4&5 are research satellites based on the Space Flight Laboratory’s Generic Nanosatellite Bus, devoted to the study of star brightness and formation flying, respectively. Novel low-cost testing procedures are developed and used to characterize satellite sensor and actuator performance. The algorithm governing the pointing of CanX-4&5 is enhanced based on preliminary simulation results. A linear-time invariant controller architecture, applicable to both BRITE and CanX-4&5, is designed based on simulation of several competing controllers. Testing information is combined with control laws and controller to simulate the attitude performance of the satellites throughout their missions.

This thesis determined the feasibility of developing a 16-inch, gun-launched anti-satellite weapon. The general performance capability of rocket-and scramjet-boosted, gun-launched vehicles is examined with regards to propelling a miniature homing vehicle to a satellite intercept altitude. Rocket and scramjet boost vehicle performance is modeled and optimum trajectories are determined. A low gun elevation at launch and a pop-up manuever are required to maximize the scramjet boost vehicle acceleration potential. The rocket boost vehicle is capable of intercepting a low altitude satellite without a pop-up manuever from a gun elevation of 45 degrees. Both boost methods provide apogees consistent with the intercept of known Soviet Electronic Intelligence Ocean Reconnaissance satellites, EORSAT, and Radar Ocean Reconnaissance satellites, RORSAT.

No description available.

Satellite images have been used as a complementary information for geological studies. In order to realise the maximum potential of satillite imagery, then improvements are needed, both in the visual presentation of such images, and in their automatic classification , in order to reveal the rock differences. Methods of processing imagery, were evaluated (band ratio, principal components, decorrelated stretch and maximum likelihood) and new (canonical regression, hue-saturation-intensity HSI transform, with modified manipulation, and watershed) were evaluated with respect to their ability to reveal rock differences. It was found that the HSI method gave the best results, both for visual presentation and automatic classifcation. This method has the ability to enhance both spectral and spatial information simultaneously without any data loss which is not the case in the other image enhancement methods (band ratio, principal components or decorrelation stretch). For automatic classification, the 'hue' images produced by the HSI transformation typically gave accurate (91%) classification of all the major rock types. Further, it was shown that the watershed method of classification was superior error rate = 9% to the maximum likelihood method (error rate 14%) for the same inputs. The new method of canonical regression was evaluated and although it was not very successful, the results were encouraging and it was concluded that this method may enable the estimation of the chemical composition of exposed rocks directly from satellite imagery.

Thesis (M. S. - Hydrology and Water Resources)--University of Arizona, 2001. / Includes bibliographical references (leaves 112-115).

Thèses (Ph.D.)--Université de Sherbrooke (Canada), 1997. / Titre de l'écran-titre (visionné le 20 juin 2006). Publié aussi en version papier.

Thèses (Ph.D.)--Université de Sherbrooke (Canada), 2002. / Titre de l'écran-titre (visionné le 20 juin 2006). Publié aussi en version papier.