Search NASA⌕ Search

Engineering topics

Kowalik, W. S.

Publications and source records attributed to Kowalik, W. S..

8 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

Resolving the percentage of component terrains within single resolution elements

An approximate maximum likelihood technique employing a widely available discriminant analysis program is discussed that has been developed for resolving the percentage of component terrains within single resolution elements. The method uses all four channels of Landsat data simultaneously and does not require prior knowledge of the percentage of components in mixed pixels. It was tested in five cases that were chosen to represent mixtures of outcrop, soil and vegetation which would typically be encountered in geologic studies with Landsat data. For all five cases, the method proved to be superior to single band weighted average and linear regression techniques and permitted an estimate of the total area occupied by component terrains to within plus or minus 6% of the true area covered. Its major drawback is a consistent overestimation of the pixel component percent of the darker materials (vegetation) and an underestimation of the pixel component percent of the brighter materials (sand).

Marsh, S. E.↗
NASA NTRS1976

Evaluation of LANDSAT-2 (ERTS) images applied to geologic structures and mineral resources of South America

The author has identified the following significant results. The Salar of Coposa is located in northern Chile along the frontier with Bolivia. The surface was divided into six general classes of materials. Analysis of LANDSAT image 1243-14001 by use of interactive multispectral computer (Image 100) enabled accurate repetition of these general classes based on reflectance. The Salar of Uyuni is the largest of the South American evaporite deposits. Using image 1243-13595, and parallel piped computer classification of reflectance units, the Salar was divided into nine classes ranging from deep to shallow water, water over salt, salt saturated with water, and several classes of dry salt.

Carter, W. D.↗
NASA NTRS1975

Lineaments and Mineral Occurrences in Pennsylvania

The author has identified the following significant results. A conservative lineament map of Pennsylvania interpreted from ERTS-1 channel 7 (infrared) imagery and Skylab photography was compared with the distribution of known metallic mines and mineral occurrences. Of 383 known mineral occurrences, 116 show a geographical association to 1 km wide lineaments, another 24 lie at the intersection of two lineaments, and one lies at the intersection of three lineaments. The Perkiomen Creek lineament in the Triassic Basin is associated with 9 Cu-Fe occurrences. Six Pb-Zn occurrences are associated with the Tyrone-Mount Union lineament. Thirteen other lineaments are associated with 3, 4, or 5 mineral occurrences each.

Mcmurtry, G. J.↗
NASA NTRS1975

Comparison of Skylab and Landsat Lineaments with Joint Orientations in Northcentral Pennsylvania

The author has identified the following significant results. The histogram peaks of lineaments mapped from Skylab photograph at a scale of 1:517,000 lie subparallel, within 20 deg, to major shale joints and coal cleats on part of the Allegheny Plateau. The Landsat lineament, mapped at 1:989,000 are biased by illumination and scan line directions. While there is an illumination bias in the Skylab photograph, its direction does not coincide with the main transverse lineament trend, thus providing an independent assessment of the illumination direction bias. The coincidence in direction regardless of scale of the linear features suggests a mechanical relationship between joints, fracture traces, and lineaments which is more consistent with a tensional model than a shear model of origin.

Mcmurtry, G. J.↗
NASA NTRS1975

Diazo Printing of ERTS Color Composites

The author has identified the following significant results. ERTS-1 color composites were made with the help of a Diazo developer and printer. Five single channel, density standards were established, using typical ERTS images, in order to determine exposure time. These standards were used to develop a graph from which the exposure time for any transparency can be estimated. Exposure times varied from 3 to 30 minutes, and clear colored polyester sheets from two manufactures were used with slightly different, but equally successful, results.

Mcmurtry, G. J.↗
NASA NTRS1975

Interpretation and mapping of gypsy moth defoilation from ERTS (LANDSAT)-1 temporal composites

The author has identified the following significant results. Photointerpretation of temporally composited color Diazo transparencies of ERTS(LANDSAT) images is a practical method for detecting and locating levels of widespread defoliation. ERTS 9 x 9 inch images are essentially orthographic and are produced at a nearly constant 1:1,000,000 scale. This allows direct superposition of scenes for temporal composites. ERTS coverage provides a sweeping 180 km (110 mile) wide view, permitting one interpreter to rapidly delineate defoliation in an area requiring days and weeks of work by aerial surveys or computerized processing. Defoliation boundaries can be located on the images within maximum errors on the order of hundreds of meters. The enhancement process is much less expensive than aerial surveys or computerized processing. Maps produced directly from interpretation are manageable working products. The 18 day periodic coverage of ERTS is not frequent enough to replace aerial survey mapping because defoliation and refoliation move as waves.

Mcmurtry, G. J.↗
NASA NTRS1975

Application of satellite photographic and MSS data to selected geologic and natural resource problems in Pennsylvania. 1: Lineaments and mineral occurrences in Pennsylvania. 2: Relation of lineaments to sulfide deposits: Bald Eagle Mountain, Centre County, Pennsylvania. 3: Comparison of Skylab and LANDSAT lineaments with joint orientations in north central Pennsylvania

Those metallic mineral occurrences in Pennsylvania are reported which lie near lineaments mapped from LANDSAT-1 satellite imagery and verified from Skylab photography where available. The lineaments were categorized by degree of expression and type of expression; the mineral occurrences were classified by host rock age, mineralization type, and value. The accompanying tables and figure document the mineral occurrences geographically associated with lineaments and serve as a base for a mineral exploration model.

Kowalik, W. S.↗