The in-flight absolute radiometric calibration of the Thematic Mapper (TM) is being conducted using the results of field measurements at White Sands, New Mexico. These measurements are made to characterize the ground and atmosphere at the time the TM is acquiring an image of White Sands. The data are used as input to a radiative transfer code that computes the radiance at the entrance pupil of the TM. The calibration is obtained by comparing the digital counts associated with the TM image of the measured ground site with the radiative transfer code result. The calibrations discussed here are for the first four visible and near-infrared bands of the TM. In this dissertation the data reduction for the first calibration attempts on January 3, 1983, and July 8, 1984, is discussed. Included are a review of radiative transfer theory and a discussion of model atmospheric parameters as defined for the White Sands area. These model parameters are used to assess the errors associated with the calibration procedure. Each input parameter to the radiative transfer code is varied from its model value in proportion to the uncertainty with which it can be determined. The effects of these uncertainties on the predicted radiances are determined. It is thought that the optical depth components τ(Ray), τ(Mie), τ(oz), and τ(H₂O) can be measured to within 10%, 2%, 10%, and 30%, respectively. For the white gypsum sand, surface reflectance uniformity is on the order of 1.5%, and the overall uncertainty in measured reflectance is about 2%. This is due to an uncertainty in the reflectance factor of the calibration plates. The greatest uncertainty in calibration is attributed to our uncertainty in the aerosol parameters, in particular the imaginary component of refractive index. The cumulative effect of these uncertainties is thought to produce an uncertainty in computed radiance of about 5%.

No description available.

Thesis (M.S.)--Brigham Young University. Dept. of Geography, 2006. / Includes bibliographical references (p. 50-53).

Thesis (B.S.)--Rochester Institute of Technology, 1983. / Typescript. Includes bibliographical references.

Thesis (M.S.)--Rochester Institute of Technology, 1987. / Typescript. Includes bibliographical references (leaves 129-134).

Thèses (M.Env.)--Université de Sherbrooke (Canada), 2005. / In ProQuest dissertations and theses. Titre de l'écran-titre (visionné le 17 oct. 2007). Publié aussi en version papier.

Thèses (M.Sc.)--Université de Sherbrooke (Canada), 2006. / Titre de l'écran-titre (visionné le 23 juin 2008). In ProQuest dissertations and theses. Publié aussi en version papier.

Thesis (M.A.)--Carleton University, 1988. / Also available in electronic format on the Internet.

Texte remanié de: Doctoral diss.--Austin--University of Texas, 1992. Titre de soutenance : Privatizing space-derived data : a case study of the effects of the Land remote-sensing commercialization act of 1984 on the academic geography community. / Notes bibliogr. Bibliogr. p.287-314. Index.

Landslides in the landscape exhibit predictable properties of shape, structure and orientation. These properties are reflected to varying degrees in their depiction in a satellite image. Landslides can be isolated along with similar objects in a digital image using differential and template operators. Extraction of the landslide features from these images can proceed using a logic-based model which draws on an appropriate object definition approximating the depiction of the landslides in an edge-operated image and a digital elevation model. An object extraction algorithm based on these concepts is used in repeated trials to ascertain the effectiveness of this automated approach. A low resolution linear object definition (Fischler et al. , 1981) is used to isolate candidate pixel segments in three enhanced images. These segments are classified as landslides or non-landslides according to their image pixel intensity, length, slope, and orientation. Digital elevation data is used to evaluate slope and orientation criteria. Results are compared to an inventory of landslides made using aerial photographs. Study results indicate that 17% to 28% of landslides in the image are identified for trials that produce a commission error rate of less than 50%. Commission errors are dominated by image objects related to roads and waste wood areas in clearcuts. A higher rate of successful identification was noted for landslides which occurred within 15 years of image acquisition (24% to 32%), and was most apparent for the subset of that group which was located in areas that were harvested more than 15 years before acquisition or were unharvested (29% to 38%). Successful identifications in the trials are dominated by events greater than 300 metres long and wider than 20 metres. The results suggest that the approach is more reliable in unharvested areas of the image. The poor quality of the digital elevation data, specifically artifacts produced by the contour-to-grid algorithm, was partly responsible for errors of commission and omission. The simplicity of the object definition used is another factor in error production. The methodology is not operational, but represents a realistic approach to scene segmentation for resource management given further refinement. / Forestry, Faculty of / Graduate